{"id":774,"date":"2021-04-08T14:26:05","date_gmt":"2021-04-08T14:26:05","guid":{"rendered":"https:\/\/picockpit.com\/raspberry-pi\/?p=774"},"modified":"2023-11-23T02:13:08","modified_gmt":"2023-11-23T02:13:08","slug":"c-extension-for-micropython-on-raspberry-pi-pico","status":"publish","type":"post","link":"https:\/\/picockpit.com\/raspberry-pi\/sv\/c-extension-for-micropython-on-raspberry-pi-pico\/","title":{"rendered":"C-f\u00f6rl\u00e4ngning f\u00f6r MicroPython p\u00e5 Raspberry Pi Pico"},"content":{"rendered":"

Det h\u00e4r \u00e4r en guide f\u00f6r hur man skriver och k\u00f6r ett grundl\u00e4ggande C-till\u00e4gg f\u00f6r MicroPython p\u00e5 Raspberry Pi Pico. Jag kommer att behandla sk\u00e4len till att ut\u00f6ka MicroPython, hur man skriver till\u00e4ggsmodulen, hur man kompilerar den och hur man installerar den p\u00e5 Pico. Om du vill l\u00e4sa mer om det h\u00e4r \u00e4mnet kan du l\u00e4sa f\u00f6ljande https:\/\/docs.micropython.org\/en\/latest\/develop\/extendingmicropython.html<\/a><\/p>\n\n\n\n

Introduktion<\/h2>\n

Varf\u00f6r ut\u00f6ka MicroPython?<\/h3>\n

Det kan finnas flera anledningar till varf\u00f6r du vill ut\u00f6ka MicroPython. Eftersom MicroPython \u00e4r en nedbantad version av Python fungerar det inte s\u00e4rskilt bra n\u00e4r det g\u00e4ller ber\u00e4kningstunga uppgifter (som Python). C \u00e5 andra sidan \u00e4r verkligen v\u00e4l l\u00e4mpad f\u00f6r s\u00e5dana uppgifter. Ett C-f\u00f6rl\u00e4ngningstill\u00e4gg f\u00f6r Micropython g\u00f6r det m\u00f6jligt att utf\u00f6ra dessa ber\u00e4kningar med hj\u00e4lp av C-spr\u00e5ket och anv\u00e4nda resultaten i MicroPython. Detta kan p\u00e5skynda vissa processer med en storleksordning.<\/p>\n

En annan anledning kan vara att du vill koppla ihop en maskinvara som anv\u00e4nder ett C API fr\u00e5n MicroPython. <\/p>\n

Typer av MicroPython C-till\u00e4gg<\/h3>\n

Det finns tv\u00e5 olika s\u00e4tt att ut\u00f6ka MicroPython: externa C-moduler och inhemsk maskinkod i .mpy-filer.<\/p>\n

F\u00f6r att k\u00f6ra en extern C-modul m\u00e5ste du kompilera om den till MicroPython-firmware. Detta \u00e4r en ganska komplicerad process, vilket \u00e4r anledningen till att den h\u00e4r guiden kommer att fokusera p\u00e5 det andra alternativet. Om du dock \u00e4r intresserad av detta tillv\u00e4gag\u00e5ngss\u00e4tt kan du l\u00e4sa mer om det p\u00e5 dessa webbsidor:                https:\/\/docs.micropython.org\/en\/latest\/develop\/cmodules.html<\/a>                      https:\/\/www.raspberrypi.org\/forums\/viewtopic.php?t=300352<\/a><\/p>\n

.mpy \u00e4r en fil som lagrar kompilerad maskinprogramkod och kan l\u00e4nkas dynamiskt. Detta g\u00f6r den mycket mer flexibel eftersom du inte beh\u00f6ver kompilera om hela MicroPython firmware.<\/p>\n\n\n\n

Skriva till\u00e4ggsmodulen<\/h2>\n\n\n\n

Att skriva till\u00e4ggsmodulen \u00e4r den enklaste delen av att ut\u00f6ka MicroPython. Jag kommer att visa dig hur du g\u00f6r det genom att titta p\u00e5 ett enkelt exempel. Till att b\u00f6rja med skapar vi en ny katalog som heter factfib<\/em>. \u00d6ppna ett nytt terminalf\u00f6nster, cd:a till den nya katalogen och skapa en ny fil med namnet factfib.c<\/em>. Om du har skapat katalogen p\u00e5 en Raspberry Pi under Dekstop ser kommandot ut s\u00e5 h\u00e4r.<\/p>\n\n\n\n

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cd<\/span> <\/span>~\/<\/span>Desktop<\/span>\/<\/span>factfib<\/span><\/span>\n<\/span>\ntouch<\/span> <\/span>factfib<\/span>.<\/span>c<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
\u00d6ppna factfib.c<\/em><\/span> i din favorittextredigerare och ange f\u00f6ljande kod:<\/span><\/span><\/span><\/p>\n\n\n\n
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#<\/span>include<\/span> <\/span>"<\/span>py\/dynruntime.<\/span>h<\/span><\/span>\n<\/span>\nSTATIC<\/span> <\/span>mp_int_t<\/span> <\/span>factorial_helper<\/span>(<\/span>mp_int_t<\/span> <\/span>x<\/span>) <\/span>{<\/span><\/span>\n   <\/span>if<\/span> (<\/span>x<\/span> <\/span><<\/span> <\/span>1<\/span>) <\/span>{<\/span><\/span>\n      <\/span>return<\/span> <\/span>1<\/span>;<\/span><\/span>\n   <\/span>}<\/span><\/span>\n   <\/span>return<\/span> <\/span>x<\/span>*<\/span>factorial_helper<\/span>(<\/span>x<\/span>-<\/span>1<\/span>)<\/span>;<\/span><\/span>\n}<\/span><\/span>\n<\/span>\nSTATIC<\/span> <\/span>mp_obj_t<\/span> <\/span>factorial<\/span>(<\/span>mp_obj_t<\/span> <\/span>x_obj<\/span>) <\/span>{<\/span><\/span>\n   <\/span>mp_int_t<\/span> <\/span>x<\/span> <\/span>=<\/span> <\/span>mp_obj_get_int<\/span>(<\/span>x_obj<\/span>)<\/span>;<\/span><\/span>\n   <\/span>mp_int_t<\/span> <\/span>rslt<\/span> <\/span>=<\/span> <\/span>factorial_helper<\/span>(<\/span>x<\/span>)<\/span>;<\/span><\/span>\n   <\/span>return<\/span> <\/span>rslt<\/span>;<\/span><\/span>\n}<\/span><\/span>\n<\/span>\nSTATIC<\/span> <\/span>MP_DEFINE_CONST_FUN_OBJ_1<\/span>(<\/span>factorial_obj<\/span>,<\/span> <\/span>factorial<\/span>)<\/span>;<\/span><\/span>\n<\/span>\nSTATIC<\/span> <\/span>mp_int_t<\/span> <\/span>fibonacci_helper<\/span>(<\/span>mp_int_t<\/span> <\/span>x<\/span>) <\/span>{<\/span><\/span>\n   <\/span>if<\/span> (<\/span>x<\/span> <\/span><=<\/span> <\/span>0<\/span>) <\/span>{<\/span><\/span>\n      <\/span>return<\/span> <\/span>0<\/span>;<\/span><\/span>\n   <\/span>}<\/span><\/span>\n   <\/span>else<\/span> <\/span>if<\/span> (<\/span>x<\/span> <\/span>==<\/span> <\/span>1<\/span>) <\/span>{<\/span><\/span>\n      <\/span>return<\/span> <\/span>1<\/span>;<\/span><\/span>\n   <\/span>}<\/span><\/span>\n   <\/span>else<\/span> <\/span>{<\/span><\/span>\n      <\/span>return<\/span> (<\/span>fibonacci_helper<\/span>(<\/span>x<\/span>-<\/span>1<\/span>) <\/span>+<\/span> <\/span>fibonacci_helper<\/span>(<\/span>x<\/span>-<\/span>2<\/span>))<\/span>;<\/span><\/span>\n   <\/span>}<\/span><\/span>\n}<\/span><\/span>\n<\/span>\nSTATIC<\/span> <\/span>mp_obj_t<\/span> <\/span>fibonacci<\/span>(<\/span>mp_obj_t<\/span> <\/span>x_obj<\/span>) <\/span>{<\/span><\/span>\n   <\/span>mp_int_t<\/span> <\/span>x<\/span> <\/span>=<\/span> <\/span>mp_obj_get_int<\/span>(<\/span>x_obj<\/span>)<\/span>;<\/span><\/span>\n   <\/span>mp_int_t<\/span> <\/span>rslt<\/span> <\/span>=<\/span> <\/span>fibonacci_helper<\/span>(<\/span>x<\/span>)<\/span>;<\/span><\/span>\n   <\/span>return<\/span> <\/span>mp_obj_new_int<\/span>(<\/span>rslt<\/span>)<\/span>;<\/span><\/span>\n}<\/span><\/span>\n<\/span>\nSTATIC<\/span> <\/span>MP_DEFINE_CONST_FUN_OBJ_1<\/span>(<\/span>fibonacci_obj<\/span>,<\/span> <\/span>fibonacci<\/span>)<\/span>;<\/span><\/span>\n<\/span>\nmp_obj_t<\/span> <\/span>mpy_init<\/span>(<\/span>mp_obj_fun_bc_t<\/span> <\/span>*<\/span>self<\/span>,<\/span> <\/span>size_t<\/span> <\/span>n_args<\/span>,<\/span> <\/span>size_t<\/span> <\/span>n_kw<\/span>,<\/span> <\/span>mp_obj_t<\/span> <\/span>*<\/span>args<\/span>) <\/span>{<\/span><\/span>\n   <\/span>MP_DYNRUNTIME_INIT_ENTRY<\/span><\/span>\n<\/span>\n   <\/span>mp_store_global<\/span>(<\/span>MP_QSTR_factorial<\/span>,<\/span> <\/span>MP_OBJ_FROM_PTR<\/span>(<\/span>&<\/span>factorial_obj<\/span>))<\/span>;<\/span><\/span>\n   <\/span>mp_store_global<\/span>(<\/span>MP_QSTR_fibonacci<\/span>,<\/span> <\/span>MP_OBJ_FROM_PTR<\/span>(<\/span>&<\/span>fibonacci_obj<\/span>))<\/span>;<\/span><\/span>\n<\/span>\n   <\/span>MP_DYNRUNTIME_INIT_EXIT<\/span><\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
L\u00e5t mig f\u00f6rklara koden ovan: I MicroPython och Python \u00e4r varje variabel ett objekt. I C representerar vi dem d\u00e4rf\u00f6r som mp_obj_t<\/em>. Men ett C-program kan bara arbeta med variabler av C-typ, vilket \u00e4r anledningen till att vi m\u00e5ste omvandla objektet till en C-typ. Detta kallas Marshalling och MicroPython tillhandah\u00e5ller funktioner f\u00f6r att extrahera vilken C-typ som helst fr\u00e5n ett objekt.<\/p>\n\n\n\n
Bygg utbyggnaden<\/h2>\n\n\n\n
Vi bygger upp till\u00e4gget till en .mpy-fil med hj\u00e4lp av en Makefile. Men vi m\u00e5ste st\u00e4lla in n\u00e5gra saker f\u00f6rst. Se till att din terminal fortfarande \u00e4r \u00f6ppen i factfib<\/em> katalog. Klona sedan MicroPython GitHub-f\u00f6rr\u00e5det.<\/p>\n\n\n\n
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sudo<\/span> <\/span>apt<\/span>-<\/span>get<\/span> <\/span>install<\/span> <\/span>build<\/span>-<\/span>essential<\/span> <\/span>libreadline<\/span>-<\/span>dev<\/span> <\/span>libffi<\/span>-<\/span>dev<\/span> <\/span>git<\/span> <\/span>pkg<\/span>-<\/span>config<\/span> <\/span>gcc<\/span>-<\/span>arm<\/span>-<\/span>none<\/span>-<\/span>eabi<\/span> <\/span>libnewlib<\/span>-<\/span>arm<\/span>-<\/span>none<\/span>-<\/span>eabi<\/span><\/span>\n<\/span>\ngit<\/span> <\/span>clone<\/span> <\/span>--<\/span>recurse<\/span>-<\/span>submodules<\/span>\u00a0https<\/span>:<\/span>\/\/github.com\/micropython\/micropython.git<\/span><\/span>\n<\/span>\npip3<\/span>\u00a0<\/span>install<\/span>\u00a0<\/span>'<\/span>pyelftools>=0.25<\/span>'<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
Dessa installationer kommer att ta ett tag, men om du vill spara tid och vet vad du g\u00f6r beh\u00f6ver du bara klona katalogerna \/py och \/tools fr\u00e5n micropython-f\u00f6rr\u00e5det och l\u00e4gga dem i en micropython<\/em> i mappen factfib<\/em> mapp (hoppa \u00f6ver det andra kommandot).<\/p>\n\n\n\n
Medan installationen p\u00e5g\u00e5r kan vi anv\u00e4nda tiden till att skriva Makefilen. Exekvera helt enkelt<\/p>\n\n\n\n
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touch<\/span> <\/span>Makefile<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
och \u00f6ppna den nyskapade filen i en textredigerare.<\/p>\n\n\n\n
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MPY_DIR<\/span> <\/span>=<\/span> <\/span>micropython<\/span><\/span>\n<\/span>\nMOD<\/span> <\/span>=<\/span> <\/span>factfib<\/span><\/span>\n<\/span>\nSRC<\/span> <\/span>=<\/span> <\/span>factfib<\/span>.<\/span>c<\/span><\/span>\n<\/span>\nARCH<\/span> <\/span>=<\/span> <\/span>armv7m<\/span><\/span>\n<\/span>\ninclude<\/span> <\/span>$<\/span>(<\/span>MPY_DIR<\/span>)<\/span>\/<\/span>py<\/span>\/<\/span>dynruntime<\/span>.<\/span>mk<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
Du kanske har lagt m\u00e4rke till att vi har satt ARCH <\/em>variabeln till armv7m<\/em> \u00e4ven om pico \u00e4r armv6m<\/em>. Vi m\u00e5ste g\u00f6ra detta eftersom armv6m<\/em> arkitekturen (n\u00e4r jag skriver denna artikel) inte st\u00f6ds av dynruntime.mk<\/em> verktyg.<\/p>\n\n\n\n
Men som tur \u00e4r kan vi fortfarande kompilera ett fungerande till\u00e4gg f\u00f6r Pico. Vi beh\u00f6ver bara \u00e4ndra dynruntime.mk <\/em>filen, som b\u00f6r finnas under micropython\/py\/dynruntime.mk. <\/em>\u00d6ppna den och leta under Architecture configuration i armv7m efter variabeln CFLAGS (b\u00f6r vara rad 64). \u00c4ndra -mcpu=cortex-m3<\/em> till -mcpu=cortex-m0<\/em> och spara filen.<\/p>\n\n\n
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\"\u00e4ndra<\/figure>\n<\/div>\n\n\n
N\u00e4r allt \u00e4r installerat, k\u00f6r du sedan<\/p>\n\n\n\n
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make<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
och faktafib.mpy<\/em> filen kommer att skapas.<\/p>\n\n\n\n
Installera och testa till\u00e4gget<\/h2>\n\n\n\n
Det sista steget \u00e4r installation och testning. F\u00f6r detta anv\u00e4nder vi det filsystem som Micropython skapar p\u00e5 Raspberry Pi Pico. F\u00f6rst m\u00e5ste vi flasha Pico med MicroPython firmware. det enklaste s\u00e4ttet att g\u00f6ra detta \u00e4r att anv\u00e4nda Thonny IDE (f\u00f6rinstallerad p\u00e5 Raspbian\/Raspberry Pi OS).<\/p>\n\n\n\n
Om du inte anv\u00e4nder en Raspberry Pi f\u00f6r att programmera din Pico eller om du aldrig har anv\u00e4nt MicroPython p\u00e5 Pico tidigare, se guiden Kom ig\u00e5ng med MicroPython fr\u00e5n Raspberry Pi. https:\/\/www.raspberrypi.org\/documentation\/rp2040\/getting-started\/#getting-started-with-micropython<\/a><\/p>\n\n\n\n
Om du anv\u00e4nder Windows b\u00f6r du l\u00e4sa detta blogginl\u00e4gg om Raspberry Pi Pico och MicroPython p\u00e5 Windows. https:\/\/picockpit.com\/raspberry-pi\/raspberry-pi-pico-and-micropython-on-windows\/<\/a><\/p>\n\n\n\n
St\u00e4ng Thonny efter att du har flashat din Pico med MicroPython-firmware och installera rshell. Vi anv\u00e4nder rshell f\u00f6r att komma \u00e5t filsystemet fr\u00e5n kommandoraden.<\/p>\n\n\n\n
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sudo<\/span> <\/span>pip3<\/span> <\/span>install<\/span> <\/span>rshell<\/span><\/span>\nrshell<\/span> <\/span>--<\/span>version<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
Detta skriver ut rhsell-versionen om allt \u00e4r korrekt inst\u00e4llt. Koppla sedan ur pico och koppla in den igen (utan att h\u00e5lla BOOTSEL-knappen intryckt) f\u00f6r att se till att inget f\u00f6rs\u00f6ker komma \u00e5t filsystemet. Nu m\u00e5ste vi utf\u00f6ra<\/p>\n\n\n\n
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rshell<\/span> <\/span>-<\/span>p<\/span> <\/span>\/<\/span>dev<\/span>\/<\/span>ttyACM0<\/span> <\/span>--<\/span>buffer<\/span>-<\/span>size<\/span> <\/span>512<\/span><\/span>\n<\/span>\ncp<\/span> <\/span>factfib<\/span>.<\/span>mpy<\/span> <\/span>\/<\/span>pyboard<\/span>\/<\/span>factfib<\/span>.<\/span>mpy<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
F\u00f6r att testa installationen kan du anv\u00e4nda antingen rshell eller Thonny IDE f\u00f6r att spara din .py<\/em> filer p\u00e5 Pico, men jag kommer att visa hur man anv\u00e4nder MicroPython-tolken p\u00e5 minicom.<\/p>\n\n\n\n
Tryck d\u00e4rf\u00f6r f\u00f6rst p\u00e5 Ctrl+c<\/em> f\u00f6r att l\u00e4mna rshell och sedan installera minicom via<\/p>\n\n\n\n
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sudo<\/span> <\/span>apt<\/span> <\/span>install<\/span> <\/span>minicom<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
Nu kan vi f\u00e5 tillg\u00e5ng till Picos REPL (Read-eval-print-slinga).<\/p>\n\n\n\n
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minicom<\/span> <\/span>-<\/span>o<\/span> <\/span>-<\/span>D<\/span> <\/span>\/<\/span>dev<\/span>\/<\/span>ttyACM0<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
De tre avslutande vinkelparenteserna >>> indikerar att MicroPython-tolken k\u00f6rs. Nu kan vi importera v\u00e5rt till\u00e4gg och arbeta med det som vanligt.<\/p>\n\n\n\n
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>>><\/span> <\/span>import<\/span> <\/span>factfib<\/span> <\/span>as<\/span> <\/span>ff<\/span><\/span>\n<\/span>\n>>> <\/span>ff<\/span>.<\/span>factorial<\/span>(5)<\/span><\/span>\n<\/span>\n>>> 120<\/span><\/span>\n<\/span>\n>>> <\/span>ff<\/span>.<\/span>fibonacci<\/span>(7)<\/span><\/span>\n<\/span>\n>>> 13<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
Vi gratulerar! Du har skapat ditt f\u00f6rsta MicroPython C-till\u00e4gg f\u00f6r Pico! N\u00e4sta steg \u00e4r att l\u00e4ra dig hur man skriver och kompilerar mer komplexa moduler. Ett bra s\u00e4tt att b\u00f6rja \u00e4r att testa hur Marshalling av listor och dicts fungerar (se webbsidan Marshalling ovan). <\/p>\n\n\n\n
Om du har n\u00e5gra fr\u00e5gor om detta inl\u00e4gg \u00e4r du v\u00e4lkommen att skriva en kommentar.<\/p>\n
Den h\u00e4r webbsidan av Oliver Robson \u00e4r till stor hj\u00e4lp f\u00f6r Marshalling. https:\/\/mpy-c-gen.oliverrobson.tech\/<\/a>. Dessutom kan du hitta exempel p\u00e5 Marshalling i MicroPython-dokumentationen. https:\/\/docs.micropython.org\/en\/latest\/develop\/natmod.html<\/a>. Jag rekommenderar att du l\u00e4ser den h\u00e4r artikeln om du beh\u00f6ver ytterligare f\u00f6rklaringar.<\/p>\n\n\n\n