Cannot download program

[manie]

I have a straight forward 28x2 circuit for which I will post the schematic if needed.

I get the following error after about 1 to 2 seconds from attempting a download.
It is not the chip as I have changed chips on the board but the error remains the same.

ERROR:

Error:
Verification error - 0x00 transmitted but 0xFFFFFF80 received at byte 68

Does anyone know what this means ?

I have checked the board and traces. I have resoldered some parts. I have replaced some parts.

Can anyone help please ?
The AXE27 cable is fine as I have downloaded another program on another board...........

Thanks

 

[AllyCat]

Hi,

Did you try putting "Verification Error" into the Forum search box? There are several threads , for example this one.

It's nearly always a power supply issue of some type. Either a low battery, missing supply decoupling capacitors or an unsuitable (e.g. noisy) power supply.

Cheers, Alan.

 

[bpowell]

Post pictures of the board, post your schematic.

Is this a new design? First time trying to download?

 

[BeanieBots]

Hi manie, long time no chat.
As others have already said, almost certainly a power supply issue.
Other possibility is if you have the download circuit wrong. ie as a potential divider instead of pull-down + current limit.

 

[manie]

Hi Alleycat,Bpowell and BB...........
Thanks for the reply. Its funny, the 7805 was the first part that I replaced on the board......

I aloso power from a PC power supply and have done so for donkey's years, NO PROBLEM.
The other board I am talking about is powered from this same power at the SAME TIME, and no problem there.
I will try and replace the caps in the supply line on the board and see what happens.

bpowell, no its not a new design, it is my chicken coop controller (beanie knows this circuit well) and it has worked WELL in the past.
Yes the layout has changed somewhat but the circuit is the same as always.

I will have another look at the power supply part of it and let you know.

Thanks as always........

 

[BeanieBots]

...the layout has changed somewhat but the circuit is the same ...

That might be a clue!
If you don't find any issues with the power supply, check and double check that the new layout does not do anything like run high currents down the same cables as those used for PICAXE supply and/or ground.

Have you checked that the PICAXE giving the issue is OK in another circuit?
Whatever is causing the problem might have done permanent damage, so worth double checking that it's still OK somewhere else in a known working board.

 

[Goeytex]

You might stumble upon a resolution by arbitrarily or randomly swapping parts. But I think a better method is to use you meter or scope to isolate the problem.

Measure the voltage directly across the Picaxe power pins. Does it match the supply voltage? Check the grounds, specifically the ground from the Programming cable to the Picaxe 0V pins. Measure the resistance between Picaxe Pins 8 and 19 (0v). It should be close to zero Ohms. Then measure the resistance from these pins to the 0V pad on the download jack. It should also be close to zero Ohms.

Do the serial test (PE5) while measuring the voltage from the Picaxe 0V pin to the serin pin.

Measure the Picaxe current by putting your meter in the +V line. With no pins active ( blank program) , it should be no more than about 4 ma.

 

[manie]

Thanks guys

I am designing a NEW PCB, wasted enough time on this one already, somebody is waiting for this board to control his chicken coop...........

Thanks for the replies, I appreciate it.