Hi Everyone,
I have successfully used a Dontronics DT-001 and DT-106 to prototype a
circuit I am making. I have since made a new veroboard version of my
circuit which also works successfully.

However, I have tried to add ICSP support to the veroboard and can't get
it to work with the DT-001. I have used J1 on the dt-001 to connect
MCLR, VDD, VSS, RB6 and RB7 to the target board (5 wires), but can't get
it to read, or write to the PIC.

If I install the PIC back into the dt-106 it works OK.

I have also noticed that the PIC when in the veroboard still runs even
though the MCLR line is at Vihh (12.9v). I know this because the LCD
screen still boots up and displays the first message, rs232
communication also begins.

The MCLR line is connected in the target circut with a 10k resistor, and
diode.

I have checked continuity between MCLR, RB6 and RB7 with slot 1 of the
dt-001 board (when switch is in LOAD mode), all checked out.

RB6 and 7 are both isolated, I even have the '877 LVP pin tied to GND
with a 4.7k resistor. I am thinking that I need to externally power the
circuit prior to the dt-001 programming it so +5v can be ready and
stable before the MCLR pin goes high.

Also, low voltage programming is disabled on the target PIC.

Does anyone know of anything I can try?

I have tried isolating +5v, as well as MCLR, and still getting nowhere.

Thankyou for reading my post

Regards,
Daren


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