Help Getting Started

[mackrackit]

What are you using for an oscillator and how are the configs set?

[doggitz]

Thanks for your quick reply!

I am using the 4 MHz crystal that came mounted on the board
The configs for the programmer are:
Osc XT
Watchdog Enabled
Power-up Timer Enabled
Brown-out Enabled
Low Voltage Pgm disabled
flash pgm write All
Code NOT protected
Data EEPROM Not protected

I took these setting from the board test program that works

Thanks
Fred

[mackrackit]

Maybe try HS OSC.
But if it worked the way you have it on the sample, it is just a guess.

[Archangel]

Add these to you code:
DEFINE OSC 4 ' Tells your PIC how fast it is running
ADCON0 = 0 ' Disable A/D
CCP1CON = 0 "Disable Comparators

Power on.MCLR,BOD, . . . reset . . . Defaults to TRISD = %11111111
TrisE = %00001111 FYI check Datasheet 3.5 RE: MSP if TrisE.4 is set, As a beginner, if I were you, I would park that HP Chevelle in the garage and practice in the Toyota. A 16F628A, 16F648A, or !6f690 with PICKIT2 and Demo board, Get your feet wet with those, then go back to the 877. Just my opinion.

[doggitz]

Thanks for the advice

I did try changing the oscillator type to HS - no luck

I will try the other suggestions. I read a fair amount before investing and was under the impression that the 16F877a was a reasonable place to start. Maybe not!

Thanks

Fred

[mackrackit]

I still think the 877A is a good starter chip. It can do enough things untill you need LONGS or something like that.

Seems like there is some problem with the programs that set the fuses for you over riding the code. At least over the years it seems like this has come up before.

On the test board, is the OSC a resonator or does it have capacitors added?

Port D is non analog so that should not be the problem. MCLR has to be tied high on this one. High and Low make the pin an output so TRIS should not be it either.

I still think it is in the programers software.

[doggitz]

I think there is something wrong in the programmer. Nothing that I write in PBPRO seems to work. In fact, the ONLY thing I have gotten to run is the .hex X-1 board test file that came with the development board. The interesting thing is that this file is loaded directly into the programmer and never passes through PBPRO.

I looked at the configurations of the compiler. PBPRO came with Mecanique microcode and that is the IDE I'm using. It also came with MPLAB so I played with it a bit. According to the info that came with the compiler, for the 16F series, the IDE automatically uses MPASMWIN - so I looked at that. It is creating a hex file, so I took the hex file and passed it to the melabs USB programmer and then programmed the chip - I even used the manual clear on the programmer and then checked the memory in the chip after programming to be sure that the same hex file was present in the chip as that created by MPASM. I also switched off MPASM and opted to use the PM assembler provided - no luck. I even wrote the a simple led on/off program in assembly using the ASM...ENDASM commands in PBPRO and that didn't work. The bottom line is that nothing I do in PBPRO works. The problem is likely so fundamental that "we" are all overlooking it. Yes, the board is plugged in and I have measured the Vdd (4.99V).

Thanks

Fred