TODO: Unrelated to VTLUUG
'''PIC''' microcontrollers are a relatively popular line of [[w:Reduced_instruction_set_computing|RISC]] microcontrollers from [[w:Microchip_Technology|Microchip Technology]]. Different toolchains are required to build code between the 8-bit, 16-bit, and 32-bit data size lines. They are used in [[gp:ECE 2504 Introduction to Computer Engineering|ECE 2504 Introduction to Computer Engineering]] and [[gp:ECE 4534 Embedded System Design|ECE 4534 Embedded System Design]].
==Toolchains==
===8-Bit===
The [[freeware]] [http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en536656 MCC18 toolchain] from Microchip provides libraries and will compile and link for the 8-bit data word chips such as PIC18 devices. MCC18 can be run on Linux using wine. [http://sdcc.sourceforge.net/index.php sdcc] is a [[software libre]] toolchain that supports a [http://sdcc.sourceforge.net/doc/sdccman.html/node122.html number of PIC18 devices].
===16-Bit===
To build a nonfree toolchain for Linux, use the instructions at [http://www.electricrock.co.nz/blog/microchip-c30/]. To build a completely [[software libre]] toolchain for the PIC24 or dsPIC, follow the steps below.
<pre>
sudo apt-get install build-essential tofrodos
mkdir ~/prj/pic30
cd ~/prj/pic30
wget http://ww1.microchip.com/downloads/en/DeviceDoc/mplabalc30v3_31.tar.gz
wget http://ww1.microchip.com/downloads/en/DeviceDoc/mplabc30v3_31.tar.gz
wget http://www.electricrock.co.nz/c30/pic30-binutils-v01.tar.bz2
wget http://www.electricrock.co.nz/c30/pic30-gcc-v01.tar.bz2
tar xf mplabalc30v3_31.tar.gz
tar xf mplabc30v3_31.tar.gz
find . -type f -exec fromdos {} \;
# We don't need to "fix" the search path by adding -nonfree directories
tar xf pic30-binutils-v01.tar.bz2 --exclude=search-path-fix.diff
tar xf pic30-gcc-v01.tar.bz2 --exclude=search-path-fix.diff
for p in pic30-binutils-v01/patches/*; do patch -p0 < $p; done
for p in pic30-gcc-v01/patches/*; do patch -p0 < $p; done
cd acme
CFLAGS=-DMCHP_VERSION=v3.31-Debian ./configure --prefix="${HOME}/prj/pic30/build" --target=pic30-coff
make
cd ..
cd gcc-4.0.2/gcc-4.0.2
CFLAGS=-DMCHP_VERSION=v3.31-Debian ./configure --prefix="${HOME}/prj/pic30/build" --target=pic30-coff --enable-languages=c
make
cd ../..
</pre>
===32-Bit===
==Programmers==
See the [[PICKit 2]] article for programming your hex file natively using <code>pk2cmd</code>.
==Integrated Development Environments==
MPLAB is the freeware IDE written by Microchip. Only Windows versions of older versions were made available, although those could be run with wine and with a [[Windows virtual machine]]. The newer MPLAB X is cross-platform [[freeware]]. [http://piklab.sourceforge.net/ Piklab] is a [[software libre]] IDE for PIC microcontrollers.
==Compiling Code==
MPLAB is the IDE recommended by the ECE department. It can be run inside a Virtual Machine, programming using USB passthrough. It can also be installed under wine and the compiler used from the commandline. [http://sdcc.sourceforge.net/index.php sdcc] is a GPL C compiler with some support for PIC devices. Some GNU utilities (namely the assembler and linker, but not compiler) have been modified to support Microchip's microprocessors as part of the [http://gputils.sourceforge.net/ gputils project]. [http://piklab.sourceforge.net/ Piklab] is an IDE with support for both open source toolchains.
MPLABX, the current version of MPLAB, runs natively under Linux.
===Using Wine to Run the Toolchain===
The [http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en536656 MCC18 toolchain] can be run using wine. This page should be updated to give more detailed instructions.
===Makefile Using Wine===
The file below is a work in progress.
<pre>
# Hacked up makefile for Linux
export WINEPREFIX = /home/user/class/embedded/pic/toolchain
MCCPATH = $(WINEPREFIX)/drive_c/MCC18/bin
CC = wine $(MCCPATH)/mcc18.exe
CFLAGS = --extended -Opa-
# -D__DEBUG -Ou- -Ot- -Ob- -Op- -Or- -Od- -Opa-
LD = wine $(MCCPATH)/mplink.exe
AR = wine $(MCCPATH)/mplib.exe
PK2PATH = /home/user/class/embedded/pic/pk2cmd/pk2cmdv1.20LinuxMacSource
PK2CMD = $(PK2PATH)/pk2cmd
RM = rm
Proj1.cof : main.o messages.o interSecure Shellrupts.o user_interrupts.o my_uart.o uart_thread.o timer1_thread.o timer0_thread.o my_i2c.o
$(LD) /p18F2680 /l"C:\MCC18\lib" "main.o" "messages.o" "interrupts.o" "user_interrupts.o" "my_uart.o" "uart_thread.o" "timer1_thread.o" "timer0_thread.o" "my_i2c.o" /u_CRUNTIME /u_EXTENDEDMODE /z__MPLAB_BUILD=1 /m"Proj1.map" /w /o"Proj1.cof"
main.o : main.c ../toolchain/drive_c/MCC18/h/stdio.h ../toolchain/drive_c/MCC18/h/usart.h ../toolchain/drive_c/MCC18/h/i2c.h ../toolchain/drive_c/MCC18/h/timers.h messages.h my_uart.h my_i2c.h uart_thread.h timer1_thread.h timer0_thread.h main.c maindefs.h ../toolchain/drive_c/MCC18/h/p18f2680.h ../toolchain/drive_c/MCC18/h/stdarg.h ../toolchain/drive_c/MCC18/h/stddef.h ../toolchain/drive_c/MCC18/h/pconfig.h interrupts.h
$(CC) -p=18F2680 "main.c" -fo="main.o" $(CFLAGS)
messages.o : messages.c messages.h messages.c maindefs.h ../toolchain/drive_c/MCC18/h/p18f2680.h interrupts.h
$(CC) -p=18F2680 "messages.c" -fo="messages.o" $(CFLAGS)
interrupts.o : interrupts.c messages.h my_uart.h interrupts.c maindefs.h ../toolchain/drive_c/MCC18/h/p18f2680.h interrupts.h user_interrupts.h
$(CC) -p=18F2680 "interrupts.c" -fo="interrupts.o" $(CFLAGS)
user_interrupts.o : user_interrupts.c ../toolchain/drive_c/MCC18/h/timers.h messages.h my_uart.h user_interrupts.c maindefs.h ../toolchain/drive_c/MCC18/h/p18f2680.h ../toolchain/drive_c/MCC18/h/pconfig.h user_interrupts.h
$(CC) -p=18F2680 "user_interrupts.c" -fo="user_interrupts.o" $(CFLAGS)
my_uart.o : my_uart.c ../toolchain/drive_c/MCC18/h/usart.h messages.h my_uart.h my_uart.c maindefs.h ../toolchain/drive_c/MCC18/h/p18f2680.h ../toolchain/drive_c/MCC18/h/pconfig.h
$(CC) -p=18F2680 "my_uart.c" -fo="my_uart.o" $(CFLAGS)
uart_thread.o : uart_thread.c ../toolchain/drive_c/MCC18/h/stdio.h uart_thread.h uart_thread.c maindefs.h ../toolchain/drive_c/MCC18/h/p18f2680.h ../toolchain/drive_c/MCC18/h/stdarg.h ../toolchain/drive_c/MCC18/h/stddef.h
$(CC) -p=18F2680 "uart_thread.c" -fo="uart_thread.o" $(CFLAGS)
timer1_thread.o : timer1_thread.c ../toolchain/drive_c/MCC18/h/stdio.h messages.h timer1_thread.h timer1_thread.c maindefs.h ../toolchain/drive_c/MCC18/h/p18f2680.h ../toolchain/drive_c/MCC18/h/stdarg.h ../toolchain/drive_c/MCC18/h/stddef.h
$(CC) -p=18F2680 "timer1_thread.c" -fo="timer1_thread.o" $(CFLAGS)
timer0_thread.o : timer0_thread.c ../toolchain/drive_c/MCC18/h/stdio.h timer0_thread.h timer0_thread.c maindefs.h ../toolchain/drive_c/MCC18/h/p18f2680.h ../toolchain/drive_c/MCC18/h/stdarg.h ../toolchain/drive_c/MCC18/h/stddef.h
$(CC) -p=18F2680 "timer0_thread.c" -fo="timer0_thread.o" $(CFLAGS)
my_i2c.o : my_i2c.c ../toolchain/drive_c/MCC18/h/i2c.h messages.h my_i2c.h my_i2c.c maindefs.h ../toolchain/drive_c/MCC18/h/p18f2680.h ../toolchain/drive_c/MCC18/h/pconfig.h
$(CC) -p=18F2680 "my_i2c.c" -fo="my_i2c.o" $(CFLAGS)
clean :
$(RM) "main.o" "messages.o" "interrupts.o" "user_interrupts.o" "my_uart.o" "uart_thread.o" "timer1_thread.o" "timer0_thread.o" "my_i2c.o" "Proj1.cof" "Proj1.hex" "Proj1.map"
prog : Proj1.hex
$(PK2CMD) -A3.3 -B$(PK2PATH) -P -M -FProj1.hex -Y -T
</pre>
==Programming==
See the [[PICKit 2]] article for programming your hex file natively using <code>pk2cmd</code>. The PICKit 3 has superceded the PICKit 2 but is lacking certain features.
==Debugging Hardware==
Reading printf-style debugging messages over UART with the [[PICKit 2]] is possible from a Windows virtual machine with USB passthrough.
===I2C===
here's a variety of useful hardware available for debugging I2C:
* The [http://www.totalphase.com/products/aardvark-i2cspi/ Aardvark I2C/SPI Host Adapter] is capable of acting as either an I2C master or slave and reading and writing data over USB. There is an [https://aur.archlinux.org/packages/aardvark-gui/ AUR package] for the Aardvark GUI for 32-bit machines. VTLUUG [https://vtluug.org/files/aardvark/ mirrors] other Aardvark files since they are no longer available on the vendor's website. The Aardvark also works well in a VM with USB passthrough.
* A [[Raspberry Pi]] has two onboard I2C buses and should be able to act as a master or slave. Performance and reliability may be suboptimal.
* A [[Bus Pirate]] can act as an I2C master or slave and is suitable for human-speed interaction.
===UART===
UART can easily be debugged using an RS232 and a level shifter in the [https://en.wikipedia.org/wiki/MAX232 MAX232] family. For computers without hardware serial ports, USB to serial adapters have near-universal Linux support. For a simpler hardware setup, it may be desirable to use a Bus Pirate or Raspberry Pi as they both support 3v3 CMOS-level UART.
==External Links==
* [http://hackaday.com/2010/11/03/how-to-program-pics-using-linux/ How-to Program PICs using Linux - Hackaday] (see article and comments)
* [http://gun.io/open/43/libre-pic30-toolchain-bitbake-recipe Bounty on a libre pic30 toolchain BitBake recipe]
[[Category:Hardware hacking]]
[[Category:Classwork]]
[[Category:Pending deletion]]