Microchip ICD problem with debugging

[salamander]

Microchip ICD Problem

Hallo,
I have built an ICD with the schematic from microchip and when I try to begin with debugging (programming with the Linux icdprog software works well) I always get an error saying my MCLR voltage is wrong (but there is the right resistor on my demo board).

As I think the Problem could be the Programming voltage and an incorect reference voltage (because programming with linux also only works when I use an external 13V source) I would appreciate if you could tell me working voltage values for:
Portpin RA3 and the voltages (in debugging mode) on the 78l12 (both in/out and ground(voltage on diode to ground also)).

Thanks a lot
salamander

 

[klemm]

Microchip ICD Problem

Hi,

this is a known problem. If you use it with mplab, there is a screen on which you can see the voltage. Play with the resitors (RA0 and RA1) until you have the right voltage. You can also try to change the led with an other color (green). This led generates the referenz voltage. A another way is to play with the current through the led to get the correct voltages.
My ICD works with the following voltages:
VDD = 4,85 - 4,9V and VPP = 12,46 - 12,5 V.
After changes you can look with the "update" button for the new voltage.

Hope this helps.


Klemm

 

[salamander]

Hi,
my voltages are in this range, but it still does not work and so I would like to know the voltage comming out the 78l12 voltage regulator and the voltages generated by the LED going into the AD of the pic measured by an DVM.

thx
regards
salamander

SOrry for my bad English...

 

[crazyduck]

Hello,
You must use a led which have a direct voltage of 2V.
Look at this site:
**broken link removed**
CD

 

[salamander]

Hi,
thanks for this answer, I will try it with another LED an then we will see...

regards
salamander