A small PIC12F1840 will be use to get 2 channels 10 bit analog converter using the i2c smbus. This is to be used with the Raspberry Pi board.
Up to 5K samples per seconds is possible. Each sample conversion includes 2 channels.
The I2C bus allow us to use more than one device. Up to 117 in theory. This way it is easy to implement more Analog channels by adding more PIC cpu with a different I2C address. A special command allow to change the I2C address and store it into the build-in eeprom.
Three modes are available,
-Single shot
In this mode, a command is send to start a conversion
-Timer mode
A special timer will be use to start the conversionA2 on each n * 100us time slot. This is a continuous mode.
-Trigger mode
On each rising of the port RA5, one conversion is done. This could be use with an other PIC to create a
synchronisation between peripherals.
Files Information
Main CPU program
- RpiA2D.c This is the PIC program written in C.
- RpiA2D.hex This is the Hex file needed to burn the program into the cpu.
Test program
- A2DTest.c This is the test program to check and demonstrate the function in C .
- I2CWrapper.c This is the functions wrapper to comunicate using I2C needed in A2DTest.c .
- I2CWrapper.h This is the header of I2CWrapper.c
- I2C_A2D.h This is the header definition for the A/D converter communication protocol.
- AdTest.py This is the test program written in python to demonstrate how to use it.
Schematic
- RpiA2D.png This is the schematic on how to connect on cpu.
- RpiA2D_2.png This is the schematic on how to connect multiple cpus.
Programmer
- RpiPgm.png This is the schematic on how to connect the cpu to program it.
- burnLVP.py This is the application in python to program the cpu with the Raspberry Pi.
license
- LICENSE.txt MIT license