Reset pin 9 always LOW

Development Boards MicroMod
1

Hi there,

I’m a novice using an Atmega32 dev board and PonyProg. I am able to download codes to the MCU but they dont work and I think its because my reset pin (9) is always LOW. What code could I use to change this? Could that be the problem?

Thanks[/b]

2

The RESET (negative logic) needs to be held to ground when programming. Is the reset low when the programming dongle is disconnected from the ICSP port? It should be at logic high when in normal operation.

3

Try a 10k pull up resistor on the reset pin

Is this a commercial board or did you make it your self?

If it is a commercial board I would have thought it would have a pull up on the reset.

Does it work with the programmer connected to the board?

4

Yes I made my own board based off http://www.sparkfun.com/datasheets/AVR/ … 35-sch.gif

I find that the RESET pin is always LOW because the 5V goes through the 10K resistor, it becomes a LOW and then goes to pin 9. I’m not sure if the ZM33064 reset IC has anything to do with it.

Does anyone know?

Thanks

5

What are you using as a power supply for this board?

What is the output voltage when connected to your board?

What package is the ZM33064?

What is voltage on pin 2 (TO92) or pin 1 (SOT223) of the ZM33064?

6

The reason it’s going low after the 10k resistor is probably because the reset circuit (ZM33064) is sinking current.

This can be because of:

  1. It is not properly connected or soldered.

  2. The Vcc on the board is not above 4.5v (minimal, >4.7 should be your target).

  3. Defective or damaged product.

The third is the least likely, but I would double check the Vcc and the connections to the reset circuit.

Check:

http://www.datasheetcatalog.com/datashe … 3064.shtml

for the connection diagram (page 5 on the pdf). Note the bottom and top views.

7

Thanks for all the help guys, I really appreciate it.

I figured out one of the problems. I had the variable power supply set to 6V when it should have been 9V.

Since I made that change PonyProg works all the time now. :wink: When I connect the board to the PC and use my logic probe on pin 9 there is no light. While I’m programming the MCU, pin 9 is LOW and when it finishes downloading the program, there is no light on the probe again. Is that the way it should be? When I disconnect from the PC, pin 9 is LOW too.

After the code downloads successfully, I test the port and there is nothing (no light on the probe) Any suggestions?

Thanks

8

I got it WORKING!!!

Thanks guys. My second problem was that when I followed the ponyprog tutorial it didnt say that I had to choose RESET for the code to start running. So now I got the ports working!! :smiley:

Thanks everyone!