Iduino Hardware test points

I have built my first two Arduino Kits this week:

A MPGDuino - that works great! :)

A Iduino - that does not work great! :(

The Atmel chips both work in the MPGDuino, but they will not work on the Iduino Board.

I keep getting SYNC Errors.

I have read that this is a result of the Atmel chip not functioning and I have tried all the solutions that I could find on this board that seemed to resolve the issue - none have worked (switched board types, switched com ports, renumbered com ports, cleared all un-used com ports - No dice)

I have also double checked, and triple checked all of my solder joints, components, and have found no visible issues.


At this point, I am sitting here with my meter, wondering what I should be seeing at different pins when the device is powered up.

This leads to my question.

Does anyone have any sage advice as to what I may possibly check, or maybe some guidance as to what I should expect to see at certain test points on this board?

Thanks in advance


PS - it is a Atmel Atmega168

The first thing to test in a situation like this is the power supply. Test the power supply at the ATmega18's Vcc and Ground pins.


Thanks for your reply.

I guess I had already gotten this far, but I should report the data.

I am finding 4.35 volts between pins 7 and 8 (VCC and Ground)

So, the device has power.

I think the issue lies with the interface between the USB chip (FTDI FT232RL) and the ATmega 168. The issue is I am not certain the best way to diagnose it.

Any further guidance would be appreciated.

Warmest Regards


I am finding 4.35 volts between pins 7 and 8 (VCC and Ground)

That should be 5V if you are only measuring 4.35V it sounds like something is drawing too much current. That is probably the cause of your problems and my guess is bad wiring.

I never considered that....

I will have to grab the schematic for the board and see if I can find a short somewhere.

I just verified my incoming from the USB port at 5 volts, and I confirmed 5 volts across the usb connection just before the usb chip, so I must have something buggered up between the usb chip and the avr.

Hope I can find it.