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Topic: Etched a Purpose-Built Arduino - It Does Nothing! (Read 957 times) previous topic - next topic

trialex

It's always frustrating when it's good in theory, but just doesn't bloody work!

That said, remote de-bugging is difficult too.

I'd try...

[1] Check there is zero resistance between pins 8 and 22 of the AtMega

[2] Plug in power, and make sure you get +5V on pins 7 and 20 of the AtMEga

[3] With power still on, check you get > ~3.5V on pin 1 of the AtMega

[4] Check the LED lights up if you take out the AtMega, apply power, and plut a bit of jumper wire between pins 7 and 19 of the empty socket

SpikedCola

#6
Oct 08, 2009, 12:25 am Last Edit: Oct 08, 2009, 12:26 am by SpikedCola Reason: 1
Here's a shot with the leads connected to the outside legs of the resonator, the time/div set to .2uS and 10x magnification. Does this sound about right?


SpikedCola

#7
Oct 08, 2009, 12:38 am Last Edit: Oct 08, 2009, 12:45 am by SpikedCola Reason: 1
Quote
I'd try...

[1] Check there is zero resistance between pins 8 and 22 of the AtMega

[2] Plug in power, and make sure you get +5V on pins 7 and 20 of the AtMEga

[3] With power still on, check you get > ~3.5V on pin 1 of the AtMega

[4] Check the LED lights up if you take out the AtMega, apply power, and plut a bit of jumper wire between pins 7 and 19 of the empty socket

1. Check - 0.7 ohms between them (which is what I get if I short the probes)
2. Check - 4.84v on each pin
3. Check 0.84v on Pin 1
4. Nothing happens. I tried powering the LED by applying 3.3v from the Duemilanove to the anode of the LED, with the ground wire connected to the Duemilanove's ground, and it didnt light up either. Perhaps the LED is bad aswell. Ill swap that out right now.

EDIT replaced the LED and now it lights when I connect 19 and 7, but it still doesnt flash when I apply power with the chip on.

trialex

Quote
3. Check 0.84v on Pin 1


Well that's not considered "HIGH" in Arduino world, and pin 1 needs to be high, otherwise it is in the "reset" state.

Oh wait I meant pin 1 of the atmega (i.e. reset), not like "digital pin1" inside the arduino IDE yeah? just checking.

Your schematic / board does show a resistor going between Vcc and reset, so if you have a suitable value resistor soldered in, and are not getting a HIGH, check that area of the board.

Looking at the photo maybe the leg of the resistor isn't soldered properly to the reset line?

SpikedCola

#9
Oct 08, 2009, 01:11 am Last Edit: Oct 08, 2009, 01:15 am by SpikedCola Reason: 1
I just disconnected the via right near Pin 1 that connects the reset line to the ICSP header, and now I get > 4v on the reset pin. I hit upload and the sketch uploads! However, the LED STILL doesnt flash

EDIT I probed the pin of the 328 and saw voltage on and off, and I adjusted the socket that digital pin 13 connects to, and now the light flashes. For some reason, I guess the pin wasnt making connection. I guess this means everything is all fixed! Thanks for your help!

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