Music quartet based on a PSoC

Final Deg ee P ojec Bachelo 's deg ee in Indus ial Technology Enginee ing Music Qua e based on a PSoC REPORT Au ho : An onio Ma ínez Ga cía Di ec o : Manuel Mo eno Eguilaz Submission: Janua y 2017 Escola Tècnica Supe io d’Enginye ia Indus ial de Ba celona Music qua e based on a PSoC Page 1 Abs ac This epo de ails he mig a ion p ocess o he Qua e code om a Mic ochip PIC24 mic ocon olle , which was p e iously mig a ed by Pau Mendie a om a Mic ochip PIC18 mic ocon olle , o a CY8CKIT-042-BLE PSoC 4 mic ocon olle manu ac u ed by Cyp ess Semiconduc o . I also explains how se e al imp o emen s, bo h in sound quali y and p og am unc ionali y, ha e been implemen ed in o he inal p og am once he mig a ion was comple ed. The o iginal Qua e code, de eloped by Vic o Timo ee , syn hesized 4 di e en oices ( wo gui a s, a iolin and a bass) coo dina ed by a conduc o ask, each o which played om i s own music shee , which was s o ed in ROM. The sound samples we e gene a ed using ampli ude modula ion: he cha ac e is ic wa e o m o he ins umen (also s o ed in ROM) and i s ampli ude en elope (gene a ed h ough so wa e) we e mul iplied, and la e expo ed h ough an 8-bi PWM unning a 78 kHz. These could la e be played on speake s wi h he help o an RC il e . The p ojec was ca ied ou by con inuously es ing he so wa e on he ac ual mic ocon olle . Mo eo e , da a was ex ac ed om hese es s and compa ed wi h he simula ion o Pe e Domenech’s PIC18 code. A g ea use o he example p ojec s p o ided by Cyp ess Semiconduc o , which demons a e he ea u es o he PSoC 4 h ough simple applica ions, has also been made. I was also essen ial o analyze di e en signals wi h an oscilloscope a he labo a o y. The p og am ob ained a e comple ing he p ojec expo s he audio signal h ough a 16-bi PWM unning a 92 kHz and includes an ex a oice (a second iolin), mo e accu a e cha ac e is ic wa e o ms and imp o ed ampli ude en elopes, as well as added unc ionali y, such as an ex a oc a e and a wide no e equency ange. The epo i s p esen s he basic ope a ion o he o iginal code, which was ca e ully s udied a he beginning o he p ojec . Then, i explains how he OS (F eeRTOS) and he p og am we e mig a ed, along wi h he ex ensi e oubleshoo ing p ocess ha ollowed. Mo eo e , i de ails he imp o emen s ha we e made once he code wo ked co ec ly. Finally, sugges ions a e made o u u e imp o emen s. Page 2 Repo Con en s ABSTRACT _______________________________________________________ 1 CONTENTS _______________________________________________________ 2 1. GLOSSARY ___________________________________________________ 5 2. PREFACE ____________________________________________________ 6 2.1. P io wo ks ela ed o his p ojec ..............................................................................6 2.2. Mo i a ion ..................................................................................................................7 2.3. P e ious equi emen s ..............................................................................................7 3. INTRODUCTION _______________________________________________ 8 3.1. Objec i es .................................................................................................................8 3.2. Scope o he p ojec ..................................................................................................8 4. BASIC QUARTET OPERATION __________________________________ 10 4.1. The Conduc o ........................................................................................................10 4.2. The Ins umen s ......................................................................................................10 4.3. The Syn hesize ......................................................................................................11 4.4. Pulse Wid h Modula ion ..........................................................................................13 5. SOFTWARE MIGRATION _______________________________________ 14 5.1. F eeRTOS mig a ion...............................................................................................14 5.2. F eeRTOS con igu a ion .........................................................................................14 5.2.1. Co-ope a i e schedule .................................................................................................... 14 5.3. In oducing he TCPWM block ................................................................................15 5.4. Qua e code mig a ion ...........................................................................................16 5.4.1. Changes made o he ampli ude modula ion .................................................................. 16 5.4.2. Changes made o he PWM ............................................................................................ 17 6. QUARTET TROUBLESHOOTING ________________________________ 18 6.1. Adjus ing emp_dac ................................................................................................19 6.2. Inc easing clock speed ...........................................................................................20 6.3. Ex ac ing da a om he PSoC 4 ............................................................................21 6.4. Compa ison be ween PSoC 4 and PIC18 ..............................................................23 6.4.1. Tes ing condi ions ............................................................................................................ 23 6.4.2. S2. ................................................................................................................................... 24 6.4.3. Temp1 .............................................................................................................................. 25 6.4.4. S2. ................................................................................................................................... 25 6.4.5. Temp2 .............................................................................................................................. 26 6.4.6. Temp_dac ........................................................................................................................ 27 Music qua e based on a PSoC Page 3 6.4.7. Compa ison conclusions ................................................................................................. 27 6.5. Tempo al analysis .................................................................................................. 28 6.5.1. PWM equency e i ica ion ............................................................................................ 28 6.5.2. In e up equency .......................................................................................................... 28 6.5.3. Time implemen a ion...................................................................................................... 29 6.5.4. In e up equency e i ica ion ........................................................................................ 30 6.5.5. Tickless idle ..................................................................................................................... 32 6.6. Final co ec ions ..................................................................................................... 33 6.6.1. PWM block a ia ion ....................................................................................................... 33 6.6.2. Sound quali y co ec ion .................................................................................................. 34 7. QUARTET IMPROVEMENTS ___________________________________ 35 7.1. 16-bi PWM ............................................................................................................ 35 7.2. New ampli ude en elopes ...................................................................................... 36 7.3. Wa e o m ables wi h 128 da a poin s ................................................................... 39 7.3.1. Da a in e pola ion ............................................................................................................ 39 7.3.2. Da a eading me hod ....................................................................................................... 40 7.3.3. P og am modi ica ions .................................................................................................... 40 7.4. Wa e o m ables wi h 256 da a poin s ................................................................... 41 7.4.1. In e pola ed da a .............................................................................................................. 41 7.4.2. Code modi ica ions .......................................................................................................... 43 7.5. Wa e o m ables wi h 512 da a poin s ................................................................... 43 7.6. B oadening he no e equency ange ................................................................... 44 7.6.1. Du a ion modi ica ions ..................................................................................................... 44 7.6.2. Change in o he in ege ype ........................................................................................... 44 7.6.3. Command e-s uc u e .................................................................................................... 44 7.7. Adding an ex a oc a e .......................................................................................... 45 7.8. Adding an ex a oice ............................................................................................ 46 7.8.1. No elis and sound channel ............................................................................................. 46 7.8.2. Syn hesize modi ica ions ................................................................................................ 46 7.8.3. F eeRTOS ela ed modi ica ions .................................................................................... 47 8. FINAL QUARTET ANALYSIS ___________________________________ 50 8.1. Resou ce usage (4 oices) .................................................................................... 50 8.2. Tempo al analysis (4 oices) ................................................................................. 50 8.2.1. PWM equency ............................................................................................................... 50 8.2.2. In e up equency .......................................................................................................... 51 8.2.3. Tempo ............................................................................................................................. 51 8.2.4. Compu a ional e o o syn hesizing a sound sample .................................................... 52 8.2.5. Compu a ional e o o adjus ing emp_dac ................................................................... 53 8.2.6. Command p ocessing ..................................................................................................... 54 8.3. Resou ce usage (5 oices) .................................................................................... 55 8.4. Tempo al analysis (5 oices) ................................................................................. 55 Page 4 Repo 8.4.1. In e up du a ion .............................................................................................................. 55 9. FUTURE IMPROVEMENTS _____________________________________ 56 9.1. Blue oo h .................................................................................................................56 9.2. U ilizing ha dwa e blocks ........................................................................................56 9.3. Adding new ins umen s .........................................................................................56 9.4. Mul iple sound ou pu s ............................................................................................57 9.5. Widening he ange o no e du a ions .....................................................................57 10. PLANNING __________________________________________________ 58 11. BUDGET ____________________________________________________ 59 12. ENVIRONMENTAL IMPACT _____________________________________ 60 CONCLUSION ____________________________________________________ 61 BIBLIOGRAPHY __________________________________________________ 62 Music qua e based on a PSoC Page 5 1. Glossa y BLE: Blue oo h Low Ene gy BPM: Bea s Pe Minu e CAN: Con olle A ea Ne wo k CPU: Cen al P ocessing Uni DAC: Digi al o Analog Con e e IDE: In eg a ed De eloping En i onmen ISR: In e up Se ice Rou ine LED: Ligh -Emi ing Diode OS: Ope a ing Sys em PIC: Pe iphe al In e ace Con olle PSoC: P og ammable Sys em on a Chip PWM: Pulse Wid h Modula ion/Modula o RC: Resis o -Capaci o RF: Radio F equency ROM: Read-Only Memo y RTOS: Real Time Ope a ing Sys em SCB: Se ial Communica ion Block SRAM: S a ic Random Access Memo y TCPWM: Time Coun e Pulse Wid h Modula o UART: Uni e sal Asynch onous Recei e -T ansmi e UDB: Uni e sal Digi al Block USB: Uni e sal Se ial Bus Page 6 Repo 2. P e ace 2.1. P io wo ks ela ed o his p ojec The o igin o his p ojec goes back o Vic o Timo ee ’s usage example o he OSA RTOS [1]. Timo ee designed a p og am, which he named “Qua e ”, ha was able o syn hesize a 4-channel melody and expo i using an 8-bi PWM unning a 78 kHz so ha , wi h he help o an RC il e , i could be played on speake s o headphones. The o iginal code was w i en o a PIC16 mic ocon olle and used he OSA RTOS as an ope a ing sys em. In 2015 Pe e Domenech, a s uden a ETSEIB (Escola Tècnica Supe io d’Enginye ia Indus ial de Ba celona), succeeded in mig a ing Timo ee ’s code so ha i could be execu ed using a PIC18 mic ocon olle [2]. He chose his mic ocon olle in pa icula because i is widely a ailable a he Depa men o Elec onics a said uni e si y. Two yea s la e ano he s uden , Pau Mendie a, mig a ed Pe e Domenech’s code so ha a PIC24 could un i [3]. This mean a change om an 8-bi CPU o a 16-bi CPU and, he e o e, he expec ed o imp o e he sound quali y by inc easing he PWM esolu ion. In he end, howe e , only a 9-bi PWM unning a 31.25 kHz was achie ed and, hus, he audio quali y did no imp o e signi ican ly. He also made he necessa y changes so ha he code could un on F eeRTOS [4], a mo e uni e sal ope a ing sys em which is easie o mig a e. O he ela ed p ojec s include Juan Gallos a’s RF Music Fes i al: o ques a basada en mic ocon olado es PIC18 y RF [5] and Joan Cal e ’s CAN Music Fes i al: O ques a Basada en Mic ocon olado s PIC18 i un bus CAN [6]. The o me designed a musical o ches a whe e each ins umen was indi idually syn hesized by ou di e en PIC18 mic ocon olle s and he conduc o sen commands o no es o each ins umen h ough RF. The la e pu sued he same objec i e, bu using a CAN bus ins ead o RF as a means o communica ion. Music qua e based on a PSoC Page 7 2.2. Mo i a ion The easons ha jus i ied he c ea ion o his p ojec a e he ollowing:  Lea n how o p og am a mic ocon olle in C language.  Lea n how o use a PSoC and ge amilia ized wi h i s speci ic IDE.  Unde s and how a RTOS, mo e speci ically F eeRTOS, wo ks.  Apply he knowledge and skills lea ned in an enginee ing deg ee o a mo e p ac ical case.  Upg ade an exis ing code so ha i p oduces an imp o ed esul .  Lea n a me hod o syn hesizing music.  Deepen he pe sonal knowledge in he ields o elec onics, p og amming and music. 2.3. P e ious equi emen s Since he o iginal code is w i en in C language, i is essen ial o ha e a ce ain deg ee o unde s anding o his p og amming language be o e he ac ual p ojec can begin. In his case, an in oduc o y u o ial was consul ed [7]. Knowing he basics o digi al elec onics is also necessa y. Mo eo e , one has o amilia ize hemsel es wi h he PSoC speci ic IDE, PSoC C ea o 4.1 [8], in o de o de elop he code, ans e i o he p ocesso and manage he chip’s con igu able ha dwa e blocks. Wi h ega d o hese componen s, some o hei da ashee s ha e o be s udied ca e ully, namely he PWM [9], TCPWM [10], SCB [11], Clock [12], In e up [13] and Pins [14] componen s. In addi ion, i is impo an o s udy he pin dis ibu ion on he ki [15] whene e cable connec ions ha e o be made and o unde s and he undamen al beha io and cha ac e is ics o he F eeRTOS ope a ing sys em [16]. Page 14 Repo 5. So wa e mig a ion 5.1. F eeRTOS mig a ion The mig a ion p ocess began by es ing an example p ojec p o ided by Cyp ess Semiconduc o in which F eeRTOS was speci ically implemen ed o he PSoC 4 BLE [17]. The p ojec was buil using PSoC C ea o 4.1 [8]. This example basically de ec s when he SW2 swi ch o he CapSense Slide a e p essed and sends a message h ough one UART acco dingly. Once es ed co ec ly i was possible o mo e on o he con igu a ion o he OS. 5.2. F eeRTOS con igu a ion Fo he Qua e code o wo k co ec ly i is necessa y o change some pa ame e s inside he F eeRTOS con igu a ion. This is done by edi ing he F eeRTOSCon ig.h heade ile. Apa om disabling p e-emp ion (see sec ion 5.2.1), a i s all o he op ions we e le a hei de aul se ing. 5.2.1. Co-ope a i e schedule F eeRTOS allows he p e-emp ion o asks, which means ha du ing a ick in e up ( he OS’s own so wa e-gene a ed in e up ) a highe p io i y ask can o ce he unning ask ou o unning s a e, eplacing i . In case o he Qua e code, a con ex swi ch (changing which ask is unning) only happens when he ins umen s en e he blocked s a e o wai o he conduc o o gi e a semapho e o hem. The e o e, he co-ope a i e ask schedule was chosen, which is equi alen o disabling p e-emp ion. Music qua e based on a PSoC Page 15 5.3. In oducing he TCPWM block The nex logical s ep in he mig a ion p ocess is o es he PSoC 4’s TCPWM block and unde s and how i wo ks. In o de o do his, a TCPWM example p o ided by Cyp ess Semiconduc o was consul ed [18]. In his example p ojec , he b igh ness o a LED is con olled using he TCPWM block. Once i was success ully es ed in sepa a e, all necessa y code and con igu a ion was hen mo ed o he F eeRTOS example o check i bo h p ojec s we e compa ible. Mo e speci ically, i was necessa y o: - Replace all p e iously exis ing blocks in he TopDesign.cysch ile wi h he TCPWM block (see Fig. 5.2). - Enable he in e up componen linked o he TCPWM block (TC_ISR). This is done using he ollowing command in he main() unc ion: TC_ISR_S a Ex(In e up Handle ); - S a he TCPWM componen and con igu e i s pa ame e s. This is also done in he main() unc ion, e en hough he la e can also be done by di ec ly edi ing he block’s p ope ies: PWM_S a (); PWM_W i ePe iod(65300u); - Edi he ISR unc ion so ha i handles he TC_ISR in e up (see Fig. 5.1). - Remo e unnecessa y code om he i s example. Figu e 5.1: ISR unc ion ha handles he TCPWM in e up . Sou ce: [18] Page 16 Repo Figu e 5.2: TCPWM block, loca ed in he TopDesign.cysch ile, which con ols he b igh ness o a g een LED. Sou ce: [18] A e comple ing hese s eps, he TCPWM example wo ked as expec ed inside he F eeRTOS p ojec . Now ha he ope a ing sys em’s unc ions we e a ailable and he TCPWM block was implemen ed, all in he same p ojec , i was possible o p oceed o he mig a ion o he ac ual Qua e code. 5.4. Qua e code mig a ion The i s s ep in he code mig a ion was o copy all Qua e -speci ic iles (sinus.h, bach1067.h and elochka.h) in o he p ojec ’s olde . A e doing so, Pau Mendie a’s code [3] had o be implemen ed in o he p ojec ’s main.c ile. Ne e heless, some modi ica ions we e s ill necessa y. 5.4.1. Changes made o he ampli ude modula ion As explained in he p e ious chap e , he inal s ep in he syn hesizing p ocess is o mul iply wo signals, which was o iginally done using assembly language o mul iply wo a iables. Since mig a ing his piece o code would no be i ial ( he assembly language would be d as ically di e en ) and he PSoC 4’s p ocesso is mo e powe ul han he PIC24’s, his ope a ion was implemen ed as a simple p oduc be ween wo a iables in C language, which is mo e cos ly (compu a ionally). Music qua e based on a PSoC Page 17 5.4.2. Changes made o he PWM All o he code ela ed o he sound syn hesizing had o be in oduced in o he unc ion ha handles he in e up s while espec ing he s uc u e seen in sec ion 5.3 (see Fig. 5.1). The main di e ence is ha he in e up has o be clea ed a he s a o he unc ion and ha he pulse wid h is modula ed wi h he PWM_W i eCompa e( emp_dac) command, whe e emp_dac is he a iable ha holds he inal syn hesized sample o all 4 oices. I is also impo an o i he pe iod o he PWM so ha i s equency ma ches he desi ed alue. In o de o achie e a PWM equency o 78 kHz while using a 24 MHz clock, he pe iod has o be 300 (see calcula ion below). Page 18 Repo 6. Qua e oubleshoo ing The aim o he mig a ion p ocess desc ibed in he p e ious chap e was o achie e he same acous ic esul wi h he PSoC 4 as he one ob ained wi h he PIC mic ocon olle s. The mig a ed p og am did p oduce sound, bu i was signi ican ly di e en han wha was expec ed. The main issues we e: - The sound was highly sa u a ed. - The no es played by he p og am we e o a much highe equency han hey should be. - The melody could only be dis inguished when playing one ins umen a a ime. I wo o mo e ins umen s we e played simul aneously hey ell ou o synch oniza ion and he sound became dis o ed. - The empo was a slowe han he o iginal. - The sound had an o e all poo quali y. In his chap e , he p ocess o de ec ing and sol ing he mis akes ha caused hese aul s will be explained in de ail. This has been he mos challenging and ime-consuming pa o he p ojec . Hence, o simpli y i , se e al cha ac e is ics o he esul ing sound (lis ed below) ha e been e alua ed o e e y possible ix made o he p ojec , in acco dance wi h he legend p esen ed in able 6.1. - Cla i y: A highly sa u a ed audio signal has a loud c acking sound added o i (simila o whi e noise). This makes i bo he some o lis en o and some imes e en makes i di icul o iden i y he melody ha is being played. High cla i y will imply li le sa u a ion and ice e sa. - Accu acy o no e equency: Musical no es ha e a cha ac e is ic equency. The e o e, a syn hesize ha wo ks co ec ly should gene a e an audio signal wi h he equency o he desi ed no e. - Quali y: This is a mo e subjec i e pa ame e . Highe quali y he e will imply a mo e de ailed and ealis ic sound. - Co ec in e ac ion be ween ins umen s: T oubleshoo ing is made easie by analyzing a single oice, bu i is also impo an o check ha he sum o all 4 oices plays co ec ly. Music qua e based on a PSoC Page 19 Symbol Meaning + Sligh imp o emen ++ Signi ican imp o emen +++ C i ical imp o emen / No di e ence - Sligh wo sening -- Signi ican wo sening --- C i ical wo sening ? No es ed Table 6.1: Legend o he symbols used o desc ibe he imp o emen /wo sening o he audio esul E alua ion ables a e always ela i e o he bes con igu a ion ha has been ound a a pa icula poin . Ob iously, changes ha ha e a posi i e e ec on he esul a e kep and hose ha do no a e disca ded. 6.1. Adjus ing emp_dac A i s , i was hough ha emp_dac, he a iable ha holds he inal syn hesized sample, was no p ope ly adjus ed o he ange o alues accep ed by he PWM. Since he PWM pe iod was se o 300, any emp_dac alue ou side he ange o 0-300 would p oduce unexpec ed esul s. In he o iginal code, once all o he 4 oices we e added he esul was di ided by 4 and, la e , an o se o 128 was added. This las ope a ion was done because he wa e o m ables include nega i e alues. Howe e , since he mul iplica ion ope a ion used in his case is sligh ly di e en , he alues p oduced by he mig a ed code we e o a highe o de , and hus he a iable had o be di ided by a highe numbe . Se e al combina ions o di iso and o se we e es ed and e alua ed empi ically. Wi h a single ac i e oice, he bes esul was achie ed by di iding by 512 (shi ing 9 bi s o he igh ) and adding an o se o 220. The sound became sligh ly less sa u a ed, bu mos o he issues pe sis ed (see able 6.2). I was he e o e easonable o assume ha he e was a mo e se ious p oblem wi h he mig a ed code ha emained unde ec ed and was Page 20 Repo esponsible o he poo quali y o he esul . Cla i y + Accu acy / Quali y / Co ec in e ac ion ? Table 6.2: Sound e alua ion a e adjus ing he emp_dac a iable 6.2. Inc easing clock speed Be o e s a ing a mo e de ailed analysis o he mig a ed code’s beha io , i was decided ha i would be in e es ing o inc ease he equency o he clock ha con ols he TCPWM block. Un il now, i had been unning a he same equency as he ex e nal clock (EXTCLK), 24 MHz. Howe e , he TCPWM block allows clocks o ope a e up o a maximum o 48 MHz [10]. Choosing his clock speed means ha , i he same PWM equency is kep , he PWM pe iod should now be 600, hus doubling i s esolu ion. In o he wo ds, he emp_dac a iable would be able o hold double he amoun o di e en alues han i p e iously could. This would be equi alen o a 9-bi esolu ion. A e es ing his modi ica ion (see eco ding #1 o he annex), he quali y inc eased sligh ly bu so did he sa u a ion (see able 6.3). S ill, o e all his e sion o he mig a ed code sounded be e . Cla i y - Accu acy / Quali y + Co ec in e ac ion ? Table 6.3: Sound e alua ion a e inc easing he clock speed o 48 MHz Music qua e based on a PSoC Page 21 6.3. Ex ac ing da a om he PSoC 4 Once he PWM esolu ion and he adjus men o he emp_dac a iable we e disca ded om being esponsible o he majo sound issues, a mo e de ailed and comp ehensi e analysis o he code’s beha io was deemed necessa y. Up o his poin all da a had been ex ac ed om he PSoC using b eakpoin s in PSoC C ea o 4.1. This p ocedu e was enough o check he s a e o a iables a ce ain poin s o execu ion, bu i made sa ing la ge amoun s o da a almos impossible (sa ing da a om each in e up , o example). The e o e, i was necessa y o ind ano he way o ex ac in o ma ion. This was done by ollowing an online u o ial ha demons a ed how o implemen he p in C unc ion in o he PSoC (by de aul he unc ion compiles wi hou e o s, bu i does no hing when called) [19]. Fi s , a UART (SCB mode) block was placed in o he TopDesign.cysch ile wi h i s s anda d con igu a ion. Then, i was assigned o he co ec pins, P1.5 and P1.4 (see Fig. 6.1) and, a e wa ds, a cable connec ion was made om P1.5 o P12.6 and om P1.4 o P12.7 (see Fig. 6.2). Figu e 6.1: Pin assignmen o he UART block. Sc eensho aken om PSoC C ea o 4.1. Page 22 Repo Figu e 6.2: PSoC 4 a e making he cable connec ions o he UART block (g een cables). Sou ce: own. The ollowing s eps consis ed in inc easing he heap size, which is done in he “Sys em” ab in he .cydw ile, and adding he _w i e() unc ion o he main.c ile (see Fig. 6.3). Mo eo e , he UART block has o be s a ed wi h he UART_S a () command. Figu e 6.3: Addi ional code necessa y o he implemen a ion o he p in unc ion. Sou ce: [19]. Finally, he p og am PuTTY [20] was ins alled in o de o ecei e he in o ma ion ha he PSoC would be ansmi ing h ough USB. Music qua e based on a PSoC Page 23 6.4. Compa ison be ween PSoC 4 and PIC18 In o de o disco e wha had gone w ong in he mig a ion p ocess, a comp ehensi e compa ison o he PSoC and PIC18’s beha io was done. The PSoC’s da a was ex ac ed using he UART block (as seen in sec ion 6.3), while he PIC18 was analyzed by simula ing Pe e Domenech’s code [2] wi h he use o MPLAB IDE [21]. 6.4.1. Tes ing condi ions Bo h sys ems we e es ed in he ollowing condi ions: - Only one oice ( he iolin) was playing. - The only no e played was b0 (in Qua e no a ion) wi h a base scale o 0 and a du a ion o 4. - The a iables whose alues we e s o ed o e e y in e up we e:  S2. : Wo ks as an index o selec ing alues om he ables in sinus.h.  emp1: Holds he alue ead om he ables in sinus.h.  S2. : Inc eases by one e e y 64 in e up s and is used o gene a e he ampli ude en elope.  emp2: Holds he alue o he ampli ude en elope.  emp_dac: Holds he alue a e he ampli ude modula ion and be o e i is adjus ed. Page 30 Repo Some modi ica ions o he code in main.c we e also necessa y: - The Time block has o be s a ed in main(): Time _S a (); - The in e up associa ed wi h he ime has o be clea ed a he s a o he in e up handle unc ion ( eplacing he PWM in e up ): Time _Clea In e up (Time _INTR_MASK_TC); The modi ied p ojec was es ed wi h posi i e esul s (see eco ding #2 o he annex): he no e accu acy imp o ed signi ican ly, e en hough i was no ye co ec , and so did he sound quali y (see able 6.4). S ill, he p og am did no sound as in ended. Cla i y / Accu acy ++ Quali y ++ Co ec in e ac ion ? Table 6.4: Sound e alua ion a e changing he in e up equency. 6.5.4. In e up equency e i ica ion Jus as wi h he PWM, an oscilloscope was used o measu e he equency o in e up s. In his case, howe e , an ou pu pin had o be con igu ed (see Fig. 6.12). I was ini ialized o 0 and was se o 1 (Ou pu PinSW_W i e(1u)) a he s a o he in e up handle unc ion and back o 0 (Ou pu PinSW_W i e(0u)) a he end o i . Figu e 6.12: So wa e ou pu pin in he TopDesign.cysch ile. Sou ce: Own. Music qua e based on a PSoC Page 31 Figu e 6.13: Oscilloscope cap u e o he in e up signal. Sou ce: own. In Fig. 6.13 he high le el ep esen s he amoun o ime spen inside an in e up . This esul is qui e su p ising: No only is he in e up equency w ong (54 kHz), bu also he e is a second, unexpec ed in e up ha happens almos immedia ely a e he i s . A e u he es ing, i was concluded ha he OS was esponsible o his, because, i i was disabled (by ne e s a ing he ask schedule ), he in e up beha io was pe ec ly co ec (see Fig. 6.14). Figu e 6.14: Oscilloscope cap u e o he in e up signal while F eeRTOS was disabled. Sou ce: own. Page 32 Repo 6.5.5. Tickless idle A e lea ning ha he OS was somehow in e e ing wi h he in e up s, i seemed easonable o examine he F eeRTOS con igu a ion ile ca e ully. E e y hing seemed o be in o de , excep o his line: #de ine con igUSE_TICKLESS_IDLE 2 The F eeRTOS e e ence manual [23] was consul ed so as o lea n mo e abou i . Appa en ly, i he ickless idle is ac i e (se o 1 o 2), and only he Idle ask ( he ask ha uns when no o he asks a e able o) is unning, hen he mic ocon olle en e s a low powe s a e. This means ha he ick in e up , du ing which he OS can selec a new ask o en e he unning s a e, is s opped. This could explain he wei d beha io expe ienced be o e. Tes ing (see able 6.5) e ealed ha he in e ac ion be ween ins umen s was pe ec ly co ec (see eco ding #3 o he annex): all o hem we e audible and synch onized. Sound quali y also seemed o imp o e. As a downside, he e was mo e sa u a ion han be o e. Cla i y - Accu acy + Quali y ++ Co ec in e ac ion +++ Table 6.5: Sound e alua ion a e disabling he ickless idle. The case o no e accu acy bea s special men ion. The oo o his issue lies in a mac o called ‘Hz’ loca ed in elochka.h: #de ine Hz *64L*256/10000 This mac o’s pu pose is o ansla e a equency measu ed in He z in o he numbe o poin s in he sinus.h ables ha ha e o be skipped du ing each in e up . In o he wo ds: he p og am is designed o be cohe en wi h he no e equencies only when he in e up equency is 10 kHz. This is why he no es played a e now co ec . Music qua e based on a PSoC Page 33 6.6. Final co ec ions 6.6.1. PWM block a ia ion The sa u a ion no ed in he p e ious sec ion became wo ying, as he e was no way o adjus ing he emp_dac a iable ha comple ely sol ed i . The e o e, a di e en block ha could also wo k as a PWM was es ed. The TCPWM block ha was being used p e iously was eplaced by he PWM block [9] (see Fig. 6.15). Figu e 6.15: TopDesign.cysch ile o he main mig a ed p ojec a e eplacing he TCPWM block wi h a PWM block. Sou ce: Adap a ion o [18] and [22]. The main disad an adge o his new block is ha he maximum clock equency i allows is 12 MHz. This means ha he PWM esolu ion will be lowe (a ound 7-8 bi s) because he pe iod will necessa ily be lowe oo. Page 34 Repo Cla i y +++ Accu acy / Quali y --- Co ec in e ac ion / Table 6.6: Sound e alua ion a e swi ching he PWM block. A e e alua ing he esul ing sound (see able 6.6), he sa u a ion disappea ed (see eco ding #4 o he annex). Howe e , he quali y go signi ican ly wo se. 6.6.2. Sound quali y co ec ion Fu he analysis o he code e ealed ha he sinus.h ables we e no being ead co ec ly now. Mo e speci ically, he nega i e alues we e being con e ed in o posi i e ones. To sol e his, all o he ables in sinus.h, along wi h he emp1 a iable, we e changed in o he in ege ype (in he o iginal code hey belonged o he cha ac e ype). Cla i y / Accu acy / Quali y +++ Co ec in e ac ion / Table 6.7: Sound e alua ion a e changing he sinus.h ables in o he in ege ype. A e e i ying ha he ables we e now being ead co ec ly, he sound was e-e alua ed (see able 6.7). I seemed ha , wi h he inc ease in quali y achie ed, he sound esul was inally equi alen o ha o he p e ious p ojec s (see eco ding #5 o he annex). The e o e, he mig a ion p ocess had inished. Music qua e based on a PSoC Page 35 7. Qua e imp o emen s This chap e will be de o ed o explaining he imp o emen s made o he mig a ed Qua e p og am. Mos o hem a e designed o imp o e sound quali y, bu some add ex a unc ionali y o he p og am as well. 7.1. 16-bi PWM The mos e ec i e way o imp o e sound quali y was o inc ease he PWM bi esolu ion. In o de o do his, an exis ing p ojec by Ganesh Raaja was consul ed [24]. This p ojec consis ed in achie ing a high esolu ion PWM by combining lowe esolu ion PWM blocks (see Fig. 7.1). Figu e 7.1: Implemen a ion o he 16-bi PWM. Sou ce: Adap a ion o [24]. The PWM1 block has wo 8-bi ou pu s wi h a di e ence in du y cycle o one clock. The ou pu is selec ed by he ha dwa e cmp_sel signal, which is he ou pu signal o he PWM2 block. A 24 MHz clock is used o he PWM1 block (because i was he maximum equency i allowed), while he PWM2 clock is he e minal coun ou pu om PWM1. Page 36 Repo The e a e also se e al unc ions ha need o be added o he code in main.c. The i s wo a e he unc ions ha s a and s op he en i e 16-bi PWM (see Fig. 7.2). Figu e 7.2: Func ions ha s a ( op) and s op (bo om) he 16-bi PWM. Sou ce: [24]. I is also necessa y o implemen he unc ion ha w i es he compa e alue (pulse wid h) o he 16-bi PWM (see Fig. 7.3). Figu e 7.3: Func ion ha w i es he compa e alue o he 16-bi PWM. Sou ce: [24]. The sound ha esul ed om in oducing he high esolu ion PWM imp o ed g ea ly when compa ed o he p e ious e sion o he p og am (see eco ding #6 o he annex). 7.2. New ampli ude en elopes The nex upg ade consis ed in changing he ampli ude en elopes along wi h he way hey we e gene a ed. Ins ead o being c ea ed using simple ope a ions du ing in e up s, hey will be s o ed in ROM, ha ing al eady been calcula ed p e iously. This will allow less linea en elopes ha will gi e he sound a mo e na u al e olu ion. Fig. 7.4, 7.5 and 7.6 show he o iginal and new ampli ude en elopes o e e y ins umen . Music qua e based on a PSoC Page 37 Figu e 7.4: Compa ison be ween he o iginal and new ampli ude en elopes o he bass. Elabo a ed om Vic o Timo ee ’s code. Figu e 7.5: Compa ison be ween he o iginal and new ampli ude en elopes o he iolin. Elabo a ed om Vic o Timo ee ’s code. Figu e 7.6: Compa ison be ween he o iginal and new ampli ude en elopes o he gui a . Elabo a ed om Vic o Timo ee ’s code. Page 38 Repo These new en elopes we e s o ed in a ays inside he sinus.h ile. Las ly, he code which p e iously gene a ed he en elope had o be eplaced (see Fig. 7.7). Figu e 7.7: Compa ison be ween he o iginal (le ) and new ( igh ) code inside he syn hesize ha deals wi h he bass’s en elope. Adap ed om Vic o Timo ee ’s code. The change in sound was sub le, bu when lis ening ca e ully i was e i ied ha he ins umen s sounded mo e na u al (see eco ding #7 o he annex). In ac , he e ec can be obse ed in he ac ual eco dings (see Fig. 7.8). The o iginal wa e o ms in he audio eco ding we e mo e linea and a i icial, whe eas he new ones p esen mo e a iabili y. Figu e 7.8: Compa ison be ween he 16-bi PWM eco ding wi h he o iginal en elopes ( op) and wi h he new ones (bo om). Sou ce: own. Music qua e based on a PSoC Page 39 7.3. Wa e o m ables wi h 128 da a poin s Ano he way o imp o ing he sound quali y o he p og am is o inc ease he numbe o da a poin s ha make up one pe iod o he cha ac e is ic wa e o m o e e y ins umen . Mo e speci ically, he o iginal amoun o 64 alues will be doubled. The esul will be mo e ealis ic sounding ins umen s. 7.3.1. Da a in e pola ion The i s s ep in his p ocess is o in e pola e he o iginal da a poin s o c ea e a con inuous unc ion. The o iginal alues we e p e iously ampli ied (mul iplied by 4) so ha he e was oom o c ea e in e media e poin s. This was done o di e en pieces o he en i e se o poin s, as inding a unc ion ha desc ibed he en i e wa e o m would be oo complica ed. Fig. 7.9, 7.10 and 7.11 compa e he o iginal and new wa e o ms o e e y ins umen . Figu e 7.9: Compa ison be ween he o iginal bass wa e o m and he new one wi h double he amoun o da a poin s. Elabo a ed om Vic o Timo ee ’s da a in sinus.h. Figu e 7.10: Compa ison be ween he o iginal iolin wa e o m and he new one wi h double he amoun o da a poin s. Elabo a ed om Vic o Timo ee ’s da a in sinus.h. Page 46 Repo 7.8. Adding an ex a oice The las imp o emen made o he Qua e p og am consis ed in adding ano he oice. The idea was o in oduce ano he iolin ha played an oc a e lowe han he o iginal one, hus c ea ing a ha monized e ec be ween bo h (see eco ding #10 o he annex). 7.8.1. No elis and sound channel The i s s ep was o copy he o iginal iolin no elis , ename i and se he oc a e o 2 ins ead o 3. Also, he swi ch o his new oice was c ea ed: #de ine pin_ENABLE_VIOLIN2 1 // Swi ch iolin2 channel ON/OFF Fu he mo e, a new sound channel had o be de ined: TSound S5; // Fo channel 5 ( iolin2) 7.8.2. Syn hesize modi ica ions Addi ional code had o be in oduced in o he in e up handle unc ion so ha he new oice was co ec ly syn hesized (see Fig. 7.18 and 7.19). Figu e 7.18: F agmen o code ha syn hesizes he sound sample o iolin2. Adap ed om Vic o Timo ee ’s code. Figu e 7.19: F agmen o code ha con ols he e olu ion o he indexes o he en elope ables. Adap ed om Vic o Timo ee ’s code. Music qua e based on a PSoC Page 47 7.8.3. F eeRTOS ela ed modi ica ions The nex s eps, which we e mo e ela ed o he OS, consis ed in: 1. C ea ing a lag ha indica es ha iolin2 is playing (see Fig. 7.20). I was assigned o he nex a ailable bi (0001 0000). Figu e 7.20: De ini ion o lags o all 5 oices. Adap ed om Pau Mendie a’s code. 2. C ea ing a ask handle and a bina y semapho e o he new iolin2 ask (see Fig. 7.21). Figu e 7.21: De ini ion o all ask handles and bina y semapho es o all 5 oices. Adap ed om Pau Mendie a’s code. 3. De ining he new ask in he Task_De s.h ile (see Fig. 7.22). Figu e 7.22: De ini ion o all asks in Task_De s.h. Adap ed om Pau Mendie a’s code. Page 48 Repo 4. C ea ing he new ask and bina y semapho e in he main() unc ion (see Fig. 7.23). The code o he new ask can be seen in Fig. 7.24. Figu e 7.23: C ea ion o all asks and bina y semapho es. Adap ed om Pau Mendie a’s code. Figu e 7.24: Violin2 ask. Adap ed om Pau Mendie a’s code. 5. Edi ing he conduc o ask so ha i gi es he semapho e o he iolin2 ask as well (see Fig. 7.25). Music qua e based on a PSoC Page 49 Figu e 7.25: Conduc o ask a e adding he ex a oice. Adap ed om Pau Mendie a’s code. 6. Re-adjus ing he emp_dac a iable. Page 50 Repo 8. Final Qua e Analysis A de ailed analysis o he inal imp o ed Qua e p og am, wi h and wi hou he ex a oice, will be p esen ed in his chap e . 8.1. Resou ce usage (4 oices) SRAM 8.984 KB (54.8%) Flash 16.720 KB (12.8%) S ack 1280 by es Heap 1024 by es UDB 50% Table 8.1: Resou ces used by he inal imp o ed 4- oice Qua e p og am. Table 8.1 shows he amoun o PSoC’s esou ces consumed by he inal p og am. The SRAM and lash alues show ha he e is enough space o add mo e ins umen s o imp o emen s. UDB, which measu es he amoun o digi al blocks used, shows ha addi ional blocks could be included. 8.2. Tempo al analysis (4 oices) 8.2.1. PWM equency Figu e 8.1: Oscilloscope cap u e o he inal PWM signal. Sou ce: own. Music qua e based on a PSoC Page 51 The PWM equency, as shown in Fig. 8.1, has inc eased o 91.85 kHz because o he in oduc ion o he high esolu ion PWM. Since i is highe han he o iginal (78 kHz), he e is no p oblem wi h i . 8.2.2. In e up equency Figu e 8.2: Oscilloscope cap u e o he inal in e up signal. Sou ce: own. The in e up equency is app oxima ely 40 kHz (see Fig. 8.2), as was expec ed. The ime spen in high le el is he du a ion o an in e up . The es o i is a ailable o he OS o ca y ou i s own ope a ions, which in his case is mo e han enough. 8.2.3. Tempo Figu e 8.3: Oscilloscope cap u e ha shows he ime be ween wo consecu i e eigh h no es. Sou ce: own. Page 52 Repo The peaks shown in Fig. 8.3 ep esen he p ocessing o wo consecu i e eigh h no es. The e o e, using he ime be ween hese wo no es (162.2 ms), he empo o he song can be calcula ed: 8.2.4. Compu a ional e o o syn hesizing a sound sample Figu e 8.4: Oscilloscope cap u e ha shows he amoun o ime equi ed o syn hesize a sound sample o a single oice. Sou ce: own. Fig. 8.4 shows ha i akes he p ocesso 1.8 µs o syn hesize one sound sample o he bass. Assuming i akes mo e o less he same o syn hesize e e y oice, he p ocesso would need a ound 7.2 µs o gene a e he sample o all 4 oices, which accoun s o 60% o he o al in e up ime (see Fig. 8.2 o he o al in e up ime). Music qua e based on a PSoC Page 53 8.2.5. Compu a ional e o o adjus ing emp_dac Figu e 8.5: Oscilloscope cap u e ha shows he amoun o ime equi ed o adjus he emp_dac a iable. Sou ce: own. I is in e es ing o s udy he amoun o ime equi ed o adjus he emp_dac a iable because in he inal p og am his is done using a ma hema ical di ision. This was no possible in he PIC mic ocon olle s due o he high compu a ional cos o he ope a ion, so ins ead i was done using he bina y igh shi ope a o (>>), which is equi alen o a di ision by a powe o 2. The ma hema ical di ision, howe e , gi es mo e eedom when adjus ing emp_dac, and hus allows mos o he PWM esolu ion o be u ilized. Fig 8.5 e eals ha he ime spen making his adjus men is a ound 4.5 µs, 37% o he o al in e up ime. The e o e, i clea ly is a cos ly ope a ion, e en hough in his case his is no a p oblem due o how much ime is a ailable (in e up s ake only abou 50% o he a ailable ime, as seen in Fig 8.2). Page 54 Repo 8.2.6. Command p ocessing Figu e 8.6: Oscilloscope cap u e showing he amoun o ime du ing which he ins umen s a e wai ing o a command (high ol age). Sou ce: own. The ime spen in low ol age in Fig 8.6 ep esen s he momen when he ins umen s a e ecei ing a command om he conduc o . The es o i is spen wai ing o he command. This shows how as commands a e p ocessed. Music qua e based on a PSoC Page 55 8.3. Resou ce usage (5 oices) SRAM 9.008 KB (55.0%) Flash 17.624 KB (13.4%) S ack 1280 by es Heap 1024 by es UDB 50% Table 8.2: Resou ces used by he inal imp o ed 5- oice Qua e p og am. As i can be seen in able 8.2, he addi ion o an ex a oice ba ely has an impac on he esou ces consumed by he p og am. 8.4. Tempo al analysis (5 oices) 8.4.1. In e up du a ion Figu e 8.7: Oscilloscope cap u e showing he in e up signal ( op, CH1) and he PWM signal (down, CH2). Sou ce: own. Fig. 8.7 shows ha an en i e in e up now las s 13.53 µs, which is 1.37 µs mo e han he 4- oice e sion. The e is s ill enough ime o he OS o ca y ou i s asks. Page 62 Repo Bibliog aphy [1] Vic o Timo ee , OSA RTOS, [h p://www.picosa.na od. u/]. [2] Pe e Domenech, Aplicaciones musicales del sis ema ope a i o en iempo eal OSA RTOS, Ba celona 2015. [3] Pau Mendie a, Audio applica ion based on F eeRTOS Ope a ing Sys em, Ba celona 2017. [4] Real Time Enginee s L d., F eeRTOS O icial Websi e, [h p://www. ee os.o g/RTOS.h ml] [5] Juan Gallos a, RF Music Fes i al: o ques a basada en mic ocon olado es PIC18 y RF, Ba celona 2015. [6] Joan Cal e , CAN Music Fes i al: o ques a basada en mic ocon olado es PIC18 y bus CAN, Ba celona 2016. [7] Tu o ials Poin , C p og amming, [h ps://www. u o ialspoin .com/cp og amming/, consul ed on Augus 2017]. [8] Cyp ess Semiconduc o Co po a ion, O icial PSoC C ea o Websi e, [h p://www.cyp ess.com/p oduc s/psoc-c ea o -in eg a ed-design-en i onmen -ide] [9] Cyp ess Semiconduc o Co po a ion, Pulse Wid h Modula o (PWM) 3.30 Componen Da ashee , 2016. [10] Cyp ess Semiconduc o Co po a ion, PSoC 4 Time Coun e Pulse Wid h Modula o (TCPWM) 2.10 Componen Da ashee , 2016. [11] Cyp ess Semiconduc o Co po a ion, PSoC 4 Se ial Communica ion Block (SCB) 4.0 Componen Da ashee , 2017. [12] Cyp ess Semiconduc o Co po a ion, Clock 2.20 Componen Da ashee , 2017. [13] Cyp ess Semiconduc o Co po a ion, In e up 1.70 Componen Da ashee , 2017. [14] Cyp ess Semiconduc o Co po a ion, Pins 2.20 Componen Da ashee , 2017. [15] Cyp ess Semiconduc o Co po a ion, CY8CKIT-042-BLE Quick S a Guide, 2015. [16] Real Time Enginee s L d., Mas e ing he F eeRTOS™ Real Time Ke nel, 2016. [17] Cyp ess Semiconduc o Co po a ion, F ee RTOS wi h PSoC 4 BLE, [h ps://cyp ess.hacks e .io/42177/ ee- os-wi h-psoc-4-ble-82a61e, consul ed on Augus 2017] [18] Cyp ess Semiconduc o Co po a ion, TCPWM (PWM mode) example p ojec 2.0, Music qua e based on a PSoC Page 63 2016. [19] Alan Hawse, Implemen ing PSoC P in , [h ps://io expe .com/2017/05/10/implemen ing-psoc-p in /, consul ed on Oc obe 2017] [20] Simon Ta ham, PuTTY, [h p://www.pu y.o g/, consul ed on Oc obe 2017] [21] MICROCHIP TECHNOLOGY INC. MPLAB IDE. [h p://www.mic ochip.com/pagehandle /en-us/ amily/mplabx/]. [22] Cyp ess Semiconduc o Co po a ion, TCPWM (Time /Coun e mode) example p ojec 3.0, 2016. [23] Real Time Enginee s L d., The F eeRTOS™ Re e ence Manual, 2016. [24] Ganesh Raaja, HIGH RESOLUTION HIGH FREQUENCY PWM IN PSOC4 BLE, [h p://www.cyp ess.com/blog/psoc-hacke -blog/high- esolu ion-high- equency-pwm- psoc4-ble, consul ed on No embe 2017]. [25] Cyp ess Semiconduc o Co po a ion, AN69133 - PSoC® 3 / PSoC 5LP Easy Wa e o m Gene a ion wi h he Wa eDAC8 Componen , [h p://www.cyp ess.com/documen a ion/applica ion-no es/an69133-psoc-3-psoc-5lp- easy-wa e o m-gene a ion-wa edac8-componen , consul ed on Janua y 2018]. [26] Cyp ess Semiconduc o Co po a ion, AN62582 - AM Modula ion and Demodula ion, [h p://www.cyp ess.com/documen a ion/applica ion-no es/an62582-am-modula ion- and-demodula ion, consul ed on Janua y 2018]. [27] Vic o K emin, Analog Mul iplica ion wi h PSoC, 2010. [28] Cyp ess Semiconduc o Co po a ion, High Resolu ion DAC in PSoC 3/5, [h ps://communi y.cyp ess.com/docs/DOC-12231, consul ed on Janua y 2018]. [29] Cyp ess Semiconduc o Co po a ion, RoHS, G een and En i onmen al In o ma ion, [h p://www.cyp ess.com/suppo / ohs, consul ed on Janua y 2018].