A PIC Programmer by Raspberry Pi Pico and the cousins

WIP

RP2PIC is a LV-ICSP Programmer for the PIC16F1xxx which runs on circuitpython.

This project is based on a blog article. Thanks!

• Command Mode
• Auto-Programming Mode
• I2C Tool

For now I've just built it on a breadboard, but I'm going to make dedicated PCBs when I have time.

1. Download Circuitpython UF2 from https://circuitpython.org/downloads

2. Press button BOOTSEL on Raspberry Pi Pico

3. Connect USB cable to Raspberry Pi Pico

4. Release button BOOTSEL on Raspberry Pi Pico

5. Copy UF2 to RPI-RP2

6. After a while, CIRCUITPY should be appeared instead of RPI-RP2

RP2PIC requires a library function adafruit_datetime.mpy. It has to be download and installed under the directory /lib on the device.

1. download adafruit-circuitpython-bundle-NN.x-mpy-YYYYMMDD.zip from https://circuitpython.org/libraries.

2. copy adafruit_datetime.mpy in the zip into the folder /CIRCUITPY/lib

copy code.py into the folder CIRCUITPY

Copy the .hex file directly under /CIRCUITPY/ then RP2PIC will recognize it. RP2PIC checks the timestamp of the all .hex file.

RP2PIC has two modes.

Command Mode can be Program/Erase/Verify by CUI through USB serial terminal such like gnu screen, minicom, teraterm, etc.

To show command help, type h at the top-level prompt >.

Head 3 lines on help shows current status such as Auto-Prog, Target device name, .hex filename currently selected. The following lines show each programmer commands.

# RP2PIC - PIC16F1xxx LV-ICSP Programmer
waiting hex...
> h
Auto Prog : No
Device    : PIC16F1503
File      : 16f1503_blink_intosc.hex    2023-4-26 18:13:4

MI/MO     : Enter/Exit LV-ICSP Mode
RP/RD/RC  : Read   Program/Data/Configuration Memory
EP/ED     : Erase  Program/Data               Memory
WP/WD/WC  : Write  Program/Data/Configuration Memory
VP/VD/VC  : Verify Program/Data/Configuration Memory

Auto-Prog Mode behaves as an automatic programmer. You can program it into PIC just by Drag and Drop a hex file.

This tool is for debugging PIC devices that implement I2C slave functionality.

RP2PIC acts as an I2C master device to send and receive I2C commands to and from PIC devices. If you only test a simple circuit using I2C, you can input I2C commands to the device from the host PC and check the response while the RP2PIC is connected. To use the I2C tool, type i2c at the top level prompt >. A new prompt (e.g. I2C 0x2f>) shows the slave address of the device debugging now.

To show command help for this tool, type h at the i2c prompt I2C 0xXX>.

# RP2PIC - PIC16F1xxx LV-ICSP Programmer
waiting hex...
> i2c
I2C 0x2f> h
e.g. help          : Print examples for all I2C Tool
     help w        : Print examples for "w" commands
     h             : <alias>
     ?             : <alias>
e.g. exit          : Exit from I2C Tool
     quit          : <alias>
     !!!           : <alias>
e.g. reset         : Reset target device
e.g. scan          : Scan I2C bus then list slave addresses
e.g. addr 42       : Set 0x42 as target device
     addr          : Show target device currently set
e.g. w C4 2 15     : Write data "0xC4 0x02 0x15" to target device
     w             : Write to target device without any data
     s             : <alias>
e.g. r 8           : Read 8 bytes from target device
     r             : Read 1 byte from target device
e.g. wr 2 C2 5 10  : Write data "0x02 0xC2 0x05" to target device,
                   :  then read 10 bytes from target device
     wr 10         : Write to target device without any data,
                   :  then read 10 bytes from target device
     wr            : Write to target device without any data,
                   :  then read 1 byte from target device
e.g. test i2c_1    : Start test for i2c commands according to the test file "i2c_1"

Bisides, the I2C Tool has a simple test suite. With it, you can give a test file and run a series of tests like any other software testing environment. This feature is not as good for detailed debugging as ICE, but it will be useful for the regression test like CI.

In the test file, list the expected response for the send command and the subsequent receive command as follows.

#
# i2c_1   command test example
#

# CMD_SPEC = 0xFF	 ;; param:[],			        ret: [PROD_ID, VER, N_PORT]
wr ff 3
=> 01 01 08

# test to this testing suite, should be failed always
wr ff 3
=> 01 01 01

Once you have your test file, drag and drop it into /CIRCUITPY/ just like you would a .hex file.

After that, you can type a test command like test i2c_1 and the I2C tool will open the test file, send the commands and show a test report checking each response.

> i2c
I2C 0x2f> test i2c_1
------------------------------------------------------------
1: wr ff 3      => 01 01 08      PASS
2: wr ff 3      => 01 01 08      FAIL    Should be "01 01 01"
------------------------------------------------------------
FAILED: 1/2, Lines: 4

• rewrite the output for icsp pulse to properly
• cleanup command loop
• dedicated pcb
• spi debug tool
• uart debug tool

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