16F877A and LCD HD44780

[Archangel]

_WDT_ON try change to _WDT_OFF it could be your reset

I am NOT overly familiar with the analog stuff. What I THINK I SEE, is ADCON1 is set to use VDD & VSS as voltage reference, you can change this to an external vref for your A/D conversion in the ADCON1 register, see sect. 11.2 of the data sheet, and you can supply that vREF on AN3, also you lose about .7 volt across those diodes, you could use schottkey or germanium which switch at lower voltage.

[Acetronics2]

Hi, Joe

looks most of the config section diseappeared in the source file ...

Where are gone the TRISA/TRISB definitions ??? , that between others !!!

I know most of PBP commands set the I/O's by themselves ... but not all of them !!!
especially IF ... THEN !!!

Have a nice day ...

Alain

PS: here, the sim runs fine ...

[Archangel]

You Shore is RIGHT ! How ya doin' Alain ?
I just sort of think the author of this code expected users to download and not dissect the code, foolishly I filtered it through Google translator, then spent an hour fixing what Google did to it What I learned was the author is worried about audio pulses above 5 volts blowing the pic's inputs and he suggested resistors and zeners to clip those voltages. I am guessing he might have used it on speaker outputs, whereas our member I think wants it on his preamps.

[towlerg]

1. What voltages did you apply to the anodes of the diodes and what voltages were required to engage all 16 blocks of the display in your simulation?
2. What type of diodes did you use?
Is it possible that Proteus introduces some parameters that I cannot obtain on my protoboard and which make all the difference?

1. As I said, 2volts on the first run and 1.5 on the second. 2 and 4 Hz for both.
2. No components were changed.
It's a sim so all things are possible. BUT these are very common devices and Proteus will report wrongly configured i/o. eg. using ADC module with i/o set for digital. I agree that the prog gets no style points and relies upon defaults but it does seem to work. Sims tend to fall down with arcane timing issues (race conditions, read modify write etc.)

With all due deference to the other more PBP savy posters on this thread your problem is most likely physical. Check that you have flashed what you think you have flashed, use the pre-compiled HEX. Check component values and the circuit. Make sure your input is what you think it is.

For example, does your programmer pick up the config fuses from the HEX file? According to my trusty PicKit2 it should be 2F4D.

Good luck, George