Society of Robots - Robot Forum
Software => Software => Topic started by: d13 on June 30, 2007, 01:09:58 PM
-
Hi everyone. I'm having a problem using my AVRISP mkii. I'm very new to this so please pardon any obvious problems that I may be overlooking.
Here's the setup:
AVRISP mkii
atmega8
AVR Studio 4 (build 528)
WinAVR
The problem is that whenever I try to do anything with the atmega8 through the isp I get a "No target was detected. Ensure that the target has power". The status light is initially off and stays solid red when I try to communicate. I did the initial firmware update when prompted by AVR Studio when I first tried to connect to the ISP. I also did a manual firmware update, but I still have the same problem. I have a 4.7kOhm resister from RESET to Vcc. I tried both a 1kOhm and a about 260ohm as well. I am able to change the ISP Frequency and it is currently set to 125 kHz.
I have put up a few images of the circuit and a few AVR Studio screen shots.
http://corruptionexperiment.com/misc/mkii_error/index.html (http://corruptionexperiment.com/misc/mkii_error/index.html)
Any help would be greatly appreciated.
-
Your ISP wiring seems to be correct.
Using your voltmeter, verify the voltage to the VCC pin it should be equal to your supply voltage (+5V in this case).
Nice work on the photos!
Good luck.
-
Your ISP wiring seems to be correct.
Using your voltmeter, verify the voltage to the VCC pin it should be equal to your supply voltage (+5V in this case).
The voltage to VCC for both the atmega8 and the isp are +5v. Also, just for kicks, I checked the ribbon cable and there doesn't seem to be any breaks in the cable.
Nice work on the photos!
Thanks!
-
I have a 4.7kOhm resister from RESET to Vcc. I tried both a 1kOhm and a about 260ohm as well.
Try to use a larger resistor. The data sheet specifies 20K - 100K as the value of the RESET pull-up resistor.
Verify your wiring again. In the third photo on your site, the value of VTarget should never be ZERO if you've wired it correctly.
-
Try to use a larger resistor. The data sheet specifies 20K - 100K as the value of the RESET pull-up resistor.
Thanks for the suggestion. I tried about a 87K, but it didn't seem to help. The help file says that the LED would normally blink orange for a "Reversed target cable connection, or not correct pull-up on the reset line."
Verify your wiring again. In the third photo on your site, the value of VTarget should never be ZERO if you've wired it correctly.
I rechecked the wiring again, but I didn't find any problems.
Should the VTarget on the Board tab of the Connect dialog always read the voltage on the isp's pin 2 (VCC). (assuming GND is connected too.) For example, if pin 2 has +5v then VTarget should read 5v? I'm trying to rule out a defective ISP. I'm sure that pin 2 is +5v and the ribbon cable is good.
Thanks again for your help.
-
Thanks for the suggestion. I tried about a 87K, but it didn't seem to help. The help file says that the LED would normally blink orange for a "Reversed target cable connection, or not correct pull-up on the reset line."
Yep that's correct. I actually have a setup which uses only a 22K resistor.
Should the VTarget on the Board tab of the Connect dialog always read the voltage on the isp's pin 2 (VCC). (assuming GND is connected too.) For example, if pin 2 has +5v then VTarget should read 5v? I'm trying to rule out a defective ISP. I'm sure that pin 2 is +5v and the ribbon cable is good.
Yep.
I really can't find anything wrong with your wiring. Maybe it's a bad ISP, but that's going to be a BIG MAYBE since it should've been captured by Atmel QA.
-
Well, it turns out that I had the pins reversed on the connector. For example, pins 1 & 2 were backwards, 3 & 4, 5 & 6. The diagram that is in the help file is meant to be viewed as if you are looking down through the connector, but not as an overlay from the bottom. :P
I was a little unsure about which resistor to use, but you helped me fix that before it even became a problem.
I really appreciate your help.