Re: [avr-gcc-list] avrdude, ATMega128

[Torsten Mohr]

Hi,

> > The supply voltages look ok.
> > PEN is connected to GND.
>
> This should be VCC. Not even JTAG programming works if this is GND.

i just soldered some additional capacitors to the pcb i made.  Just when i
did this, the wire that held PEN to GND fell off.

Now the program works and i see 2.5 V with the DMM on Port B (as expected)
and i see the expected pattern on port D.

Also, i soldered the additional capacitors off again and now it also works, i
can erase and reprogram the device.

I see two possibilities now:

1. PEN has to be left open (i understand the data sheet differently)

2. when i soldered the SMD capacitors i had bad contact on some pads and
    i fixed that when i soldered the additional capacitors.


Any way, i wonder now why i can erase and reprogram the device even with
PEN left open.  According to the data sheet there is an internal pull-up and
PEN needs to be pulled low during reset.  On the PCB, PEN is now open and
by that pulled high during reset.  I measure 5V at PEN.


Thank you all for your hints.


Best regards,
Torsten.