Autosport Labs

Hi everyone.

I have 10 x HC908KX8s. I built a programmer board and programmed one of them with mjlJunior_V3.3.1.s19.

I then built a custom(reduced functionality) version of the V3 controller board to test the firmware.

However, although it passes the serial comms. loopback test, I can't communicate with the board.

Did I need to program the KX8 with a bootloader first? Of course it may be a problem with my custom board

but I can't find one yet. I've set the IRQ line, pin 4, to 5V so that the KX8 starts in User Mode.

Thanks in advance.

Yes, you need both the bootloader and app programmed for it to work correctly. Read up on the motorola / freescale documentation on how the bootloader works. Good luck!