mimoja

TLDR:

Enable I2C and disable SPI in rasp-config
Update C library for Broadcom BCM 2835
Rebuild libpif with the updated header for Pi 2 and 3 using clang/clang++

Resources

Bugblat does not longer list the resources for the original PIF on their site. They can be found here:

Enable I2C and Disable SPI

Run sudo rasp-config and choose 5 Interfacing Options in the menu.

Disable SPI
Enable I2C

Install i2ctools and check modules

Execute sudo apt install i2c-tools python-smbus to install i2c-tools

Check if both i2c_dev and i2c_2708 are present by running lsmod | grep i2c* . In case one is mising try to load them with

sudo modprobe i2c_2708
sudo modprobe i2c_dev

To auto-load them after reboot add the module name (if necessary) to /etc/modules.

Download Broadcom C wrapper library

For this library to work correctly on RPI2/3, you MUST have the device tree support enabled in the kernel. Modern Raspbian version have this enabled by default.

The C library is hosted at airspace.com. The current version as of writing is 1.52.

We build and install the library:

wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.52.tar.gz
tar xzvf bcm2835-1.52.tar.gz
cd bcm2835-1.52
./configure
make
sudo make install
cd ..

Build libpif

You can either download the Software/Firmware Bundle:

wget www.bugblat.com/products/pif/pif.zip
unzip pif.zip

Or clone the Github Repo

git clone https://github.com/bugblat/pif

Copy the downloaded bcm2835.{c,h} from the Broadcom C wrapper library to the libpif src folder: cp bcm2835-1.52/src/bcm2835.* pif/software/src

Now we try to build (which is most likely to fail): cd pif/software/src make

If building fails with errors like this:

g++ -c -o pif.o -ansi -Wall -g -fPIC -I. -DBUILDING_LIBPIF -fvisibility=hidden -fvisibility-inlines-hidden pif.cpp
pif.cpp: In member function ‘bool Tpif::_progPage(int, const uint8_t*)’:
pif.cpp:320:32: error: taking address of temporary array
   nanosleep((struct timespec[]){{0, (200 * MICROSEC)}}, NULL);
                                ^~~~~~~~~~~~~~~~~~~~~~~
pif.cpp: In member function ‘bool Tpif::setUsercode(uint8_t*)’:
pif.cpp:398:32: error: taking address of temporary array
   nanosleep((struct timespec[]){{0, (200 * MICROSEC)}}, NULL);
                                ^~~~~~~~~~~~~~~~~~~~~~~
makefile:17: recipe for target 'pif.o' failed
make: *** [pif.o] Error 1

we will have to modify the makefile as modern gcc versions (>=gcc-4) do not support using the address of a temporary array.

To solve this without modifiering the source we can simply use clang:

sudo apt install clang
sed -i 's/gcc/clang/g' makefile
sed -i 's/g++/clang++/g' makefile

Now

make
sudo make install

should succeed.

Test configuration

i2cdetect -y 1 should output something like this:

$ i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: 20 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

Lets try to access the pif via libpif: From within the pif/software folder execute: sudo python piffind.py. Which should prompt:

================= pif find ========================
Using pif library version: 'libpif,Nov 18 2017,22:23:31'

XO2 Device ID: 012bd043  - device is an XO2-7000HC

==================== bye ==========================

Congratulations! You can access your pif.

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