Code Programming Error at 0900

I have a nice little system which uses CanBus to Control 8 LED lights on a bespoke PCB.
I am using Darrel Taylors excellent SPWM_Int routines.

I have run this for several weeks now on a LABx2 board with the necesary to control four lights for test purposes.

This evening I got round to setting up the bespoke PCBs and programmed the working code.

The code ran first time, but, via telltale leds on the pcb I noticed the mapping of some lights was not correct.

A quick look at the schematic showed that B0,B1,D7,D6,D5,D4,C5,C4 are lights 1-8 respectively
The original test config is B0,B1,D4,D5,B4,B5,B6,B7

No problem I thought, just redefine the SPWM_Pin entries in the main program appropriately.

The code compiled and assembled without errors, but when I program, it quickly fails with code error at 0900.

I have changed the code back and get the same error, I then compiled back up versions of both my program and the SPWM include file, same error.

I changed the programmer hardware, same error. I tried to compile to the LAbx2 hardware and got the same error , but at 0300...

I checked all the configuration settings against 'program, Read' and the configurations are correct. I can reprogram after Read without error. Of course this is just reloading the original code back to the device.

SO....why does a new compile of 'backup' unadulterated code not program, but read back code does?

Why did it compile the first time, but not subsequently?
Clearly missing something...but what ?

Using Mpasm5.03 and PBP 2.6 Pic 18f4580

9PM brainfade may be at play here. Perhaps a fresh look in the morning.
Any wisdom most welcome.

PS
Quick question for Darrel,
I notice the last line in SPWM_Int.bas is OverSPWM:

There is no code after this and no Return ... appreciate this is an include file, so, is this a neat way to branch out of the include back to the main program? I see the sub is called from within the include....

It sounds like the chip may not be getting erased before programming.

If you are using an melabs programmer, in meprog go to Options > More Options > Set Options to Defaults.

The OverSPWM label is so the include can jump over all of it's code.
Otherwise execution would fall into a subroutine without being called from a gosub.

All include files should jump over their own subroutines.

You nailed it. Programming as expected now. Sincere thanks for your support.


I have been using this kit for about six years now and never experienced this. However MEProg does occasionally uncheck 'configuration' in 'Options , More Options , Program' . I quickly recognise the signs now and recheck it, but, anyone else experienced this? Is there a fix or update ?

Get a PicKit2.