Going backwards, can't even get a basic blinky working now

[Demon]

Started trying to get USART going on the LAB X1, but was getting garbage - couldn't figure it out, so I moved to a breadboard and started at the beginning. It doesn't get much more basic than this on a 16F877; blinky on pin D1.

#CONFIG
    __config _HS_OSC & _WDT_OFF & _WRT_OFF & _BODEN_ON & _LVP_OFF  & _CPD_OFF & _PWRTE_OFF & _DEBUG_OFF
#ENDCONFIG

DEFINE  OSC     20

ADCON1 = 7              ' A/D off, all digital
TRISD = %00000000
PORTD = %00000000

START:  PORTD = %00000000
        PAUSE   500      
        PORTD = %00000010
        PAUSE   500      

        GOTO    START
Finish: end

Compiled using PK4 successfully:

DFP Version Used : PIC16Fxxx_DFP,1.4.149,Microchip
*****************************************************

Connecting to MPLAB PICkit 4
Currently loaded versions:
Application version...........00.09.46
Boot version..................01.00.00
Script version................00.05.58
Script build number...........abbfe90327
Tool pack version ............1.15.1688
Target voltage detected
Target device PIC16F877 found.
Device Revision Id  = 0x6
Device Id = 0x9a0
*****************************************************
Erasing...
Erase successful
*****************************************************
Erasing...
The following memory area(s) will be programmed:
program memory: start address = 0x0, end address = 0x1fff
EEData memory
Programming/Verify complete
 Program Report
01-May-2023, 17:01:53
Device Type:PIC16F877
Program Succeeded.
PK4 Verify Report
01-May-2023, 17:01:53
Device Type:PIC16F877
*****************************************************
The following memory area(s) will be verified:
program memory: start address = 0x0, end address = 0x1fff
EEData memory
Verification successful.
Verify Succeeded.

• I added two power LEDs at the top to show both rails are powered.
  
  Blinky LED is on pin D1, and yet nothing happens.
  
  LED comes on if I manually apply 5V to pin.
  
  I've changed 20MHz OSC and caps.
  
  Changed MCU.

I've been trying to figure this out for waaaay too long now, I feel I'm getting dumber by the minute.

Robert




EDIT: For a sec I thought my CONFIG was obsolete, but that looks ok.

[Demon]

It gets dumber still.

I use this code in parallel with a 18F4550.

INCLUDE "ALLDIGITAL.pbp"        ; Set all pins as digital

TRISD = %00000000
PORTD = %00000000

PAUSE   2000      

START:  PORTD = %10101010
        PAUSE   500      
        PORTD = %01010101
        PAUSE   500      

        GOTO    START
Finish: end

It compiles and works just fine on the Lab X1.

It compiles on the breadboard, but doesn't run.

I move it to the Lab X1, the darn thing runs fine...?

---------------------------------------------------

3 ICs of 16F877 compile, but don't do nothing (including a new one from my stock).

1 of the old ones compiles and runs on the Lab X1, it does nothing on the breadboard.

Robert



EDIT: Oh yeah, I'm using my "weirdo" cable for my X1, and my new cable for the breadboard.

[Demon]

Update: compiled that 16F877 on the Lab X1, it blinks, but it's not consistent.

Works a bit, then stops.

If I lightly touch the IC on the X1, it starts up for some random time period.

Now I noticed I can wave my hand over the X1 to affect it.

Robert


EDIT: Linoleum floor, no carpet, barefeet.

[Demon]

Connected my Saleae probe to the oscillator on the 16F877 while it's on the X1, the thing spits out like crazy on both pins.



But when I connect to the osc while it's on the breadboard, nothing, no activity. Something is definitely wonky on that breadboard.

I tried with 18, 22 and now 33pF caps just to eliminate that possibility.

Might have dead circuits inside, that sucker's brand new too.

[Demon]

This pic was just out of curiosity. I never saw what was going on during ICSP.

Gotta love this probe.

[Demon]

I wonder if I haven't damaged by PICs with static somehow:
- 2 of my workhorse aren't programming on breadboard, ZIF adapter or Lab X1.
- 1 new one has the same problems.
- 1 workhorse works, but intermittently.
- and then there's the 18F4550 that just works, on anything.

I've handled all these ICs the same, same surfaces, same work area, nobody else here messing with them.

I must be doing something really dumb on the Lab X1, my configs or osc setting. Thing is, I haven't changed anything, the X1 OSC jumpers are always set at 20 MHz for all my ICs (A12, B12 and C23, J3 is at top position when looking at the X1 properly).

I set the 18F4550 for 1 second blink intervals, and it seems to be keeping time. I also set the 16F877 at 1 second blink intervals, but it seems to be going twice at fast.

Also, the 16F877 take a long time to erase and program; the 18F4550 takes a fraction of that, maybe 25% at max. And it's technically the same code, just the config changes.

Robert