Programming a MC908JK3ECDWE without a computer

[AdamHer]

Hi all,

I am attempting to create a programming/testing fixture for PCB that is using a MC908JK3ECDWE.

One of the features I want to have is not needing a computer to program the PCBs.

Any tips on how I can achieve this?

Thanks,
Adam

[eutectique]

Base your fixture on Raspberry Pi or Arduino.

[AdamHer]

well yeah, but I couldnt find anything about how an arduino can communicate with a microcontroller that is programmed using one wire +5V logic.

[pgo]

Gee what an old micro.

The chip can be programmed through a serial interface.  The suggested cct. from the manual is attached.
Given this circuit all you need is another micro to interact with the monitor program in the chip.
From memory the programming interface was a bit of a pain but worked OK.
Note that the chip may require Vtst ~8.5V to enter monitor mode if already programmed.
You should be able to find details on NXP (formerly Freescale/Motorola) website.
Manual  https://www.nxp.com/docs/en/data-sheet/MC68HC908JL3E.pdf
Web https://www.nxp.com/products/HC08JK-JL

The above assumes you can access the required pins (IRQ and PTB0) and can apply Vtst without conflict or damage since it is ~8.5V.

bye

[eutectique]

well yeah, but I couldnt find anything about how an arduino can communicate with a microcontroller that is programmed using one wire +5V logic.

Wiggle an arduino pin programmatically. Use a level shifter if necessary.