labjack_pic

Program PIC microcontrollers using LabJack U3

I have multiple PICkits 1, 2, and 3, but none of them can program the part I selected for my latest project. Rather than shell out for yet another PICkit, I wrote this script to program the part using a LabJack U3 which I already had lying around.

Connections

Connect GND, MCLR, ICSPDAT, ICSPCLK to FIOs on the LabJack. Defaults are:

• MCLR on FIO4
• ICSPDAT on FIO5
• ICSPCLK on FIO6

You can select different pins with the --mclr, --icspdat, and --icspclk arguments.

If your circuit is OK with 5V power and doesn't draw too much current, you can power it with VS (USB power). Otherwise arrange some other power supply. LabJack outputs are 3.3 V, so lower voltages are a bad idea.

Installation

pip3 install labjack_pic

Usage

labjack_pic [filename.hex]

This programs the hex file:

• If the hex file contains program code, it will bulk erase that area first
• If the hex file contains config words, it will erase those first
• If the hex file contains user id words, it will erase that area first
• If the hex file contains EEPROM data, it will not erase that first. It will update any bytes specified.

Devices supported

This script only supports low-voltage programming. This means MCLR is not available as a general-purpose input in the circuit. This also means that this programmer cannot recover a part that has been programmed to MCLR-as-input.

Currently supports devices covered by Programming Specification 40002317, Programming Specification 40002266, and Programming Specification 40001683B

These are:

• PIC16F1703
• PIC16LF1703
• PIC16F1704
• PIC16LF1704
• PIC16F1705
• PIC16LF1705
• PIC16F1707
• PIC16LF1707
• PIC16F1708
• PIC16LF1708
• PIC16F1709
• PIC16LF1709
• PIC16F17114
• PIC16F17115
• PIC16F17124
• PIC16F17125
• PIC16F17126
• PIC16F17144
• PIC16F17145
• PIC16F17146
• PIC16F17154
• PIC16F17155
• PIC16F17156
• PIC16F17174
• PIC16F17175
• PIC16F17176
• PIC16F18013
• PIC16F18023
• PIC16F18014
• PIC16F18024
• PIC16F18044
• PIC16F18054
• PIC16F18074
• PIC16F18015
• PIC16F18025
• PIC16F18045
• PIC16F18055
• PIC16F18075
• PIC16F18026
• PIC16F18046
• PIC16F18056
• PIC16F18076

I would accept patches to support other PICs, but larger memory devices are probably going to be obnoxiously slow to program with LabJack hardware.

Performance

The SPI clock of the U3 is relatively slow. Writing takes maybe 2-3x as long as a proper programmer that can do the full 5 MHz clock.