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Project Help and Ideas » Chip wont run/program after putting it onto PCB

April 12, 2010
by carlhako
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Hi

Ive started putting my alarm clock together onto a PCB. When putting the chip onto the board i cannot program the thing nor will it run.

Here is a photo link

This is what ive tried: . checked power getting to chip, put multimeter on pin 7-8, getting 5.01v . checked for any shorts between pins . swapped crystal over, i thought i may have put too much heat into the 1st one, thats why the current one such long legs . swapped chip, even taken it out and successfully reprogrammed it on a breadboard . isolated chip, removed ds1302 and max7219 checked serial wires running to those sockets for shorts.

output from programming notepad: Connecting to programmer: . Found programmer: Id = "ÿÿ("; type = 8 Software Version = NUL. NUL; Hardware Version = NUL. NUL avrdude: error: buffered memory access not supported. Maybe it isn't a butterfly/AVR109 but a AVR910 device?

im lost here, any suggestions? Thanks

April 12, 2010
by Rick_S
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What do the wires from pin 1 and 14 connect to?

April 12, 2010
by mongo
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Pin 14 should not be connected to anything in 'run' mode. It would be grounded for programming. Is that where the green wire is going?

It looks like you are trying to incorporate the reset function at pin 1. Just let it be V+ for the time being.

April 12, 2010
by mongo
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I mean the green and white wire at pin 14.

April 12, 2010
by carlhako
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oops should have mentioned where they go. Pin 1 & 14 goto a breadboard. Pin 1 has a tactile switch to reset it, when pressed temporarily grounding the pin. Pin 14 goes to a switch, when switched on its grounded. To put the chip into programming mode i switch the switch on and then press reset. or power it up with the switch on.

April 12, 2010
by Rick_S
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It's really hard to see from the photo what is connected where on the far side. I'm assuming based on the board that you just mimicked the circuit from your solderless breadboard.

When you plug in all your chips (with the pre-programmed micro) does your circuit work?

If not, one thing you might try (assuming you didn't miss anything in the transition) is to add a couple of capacitors on your crystal. (22pf should be fine) The inherent capacitance in the solderless breadboard may not be there in the pc board. Just connect one side of a capacitor from pin 9 of the micro and the other side to ground, then connect one side of another capacitor from pin 10 with the other side to ground. You may have an issue with the crystal oscillating. The capacitors can help that along.

Hope that helps,

Rick

April 12, 2010
by bretm
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Have you verified that pin 14 is at 0V when you try to program it? If the switch is wired incorrectly it could be floating.

April 12, 2010
by carlhako
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No the chip will not run, i replicated the same circuit i had running on the breadboard. Will try the capacitors this afternoon after work. I have not measured voltage on pin 14 but checked continuity from the leg of pin14 through to grounding pin on the voltage regulator.

April 12, 2010
by carlhako
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I have put on the other 2 capacitors that came with the nerdkit i think 22pf. i basically grounded the 2 pins 9-10 via a capacitor. Still cannot get the damb chip to program getting the same output. pin 14 to ground reads 0.01v, pin 1 is 5v when tactile switch is not pressed.

Here is a more complete pic link

There are a few jumper wires running all over the place, i think my next step is to start removing them.

April 13, 2010
by Rick_S
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I don't know, it's difficult to say. I probably would have just connected the two capacitors to the ground at pin 8 keeping the leads nice and short rather than jumping the chip with the long leads but I don't know if that would make a difference. How are you determining if the chip is running or not?? Are you looking for the bootloader to send it's string to the serial port?

If you aren't getting the bootloader string, I'd start checking for shorts or bad connections.

April 13, 2010
by bretm
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In your second picture I don't see where pin 7 is connected to the power rail. Is it underneath the board, or is the wire I saw in the first picture just hidden behind the UART wires?

April 14, 2010
by carlhako
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lol problem was so simple I hadn't connected the earth from the usb -> serial converter to the earth on my circuit. Since i was using external power i didn't hook it up.

This still doesn't explain why my chip wasn't running but at least now I can put in debugging code to see whats going on.

Thanks for the help bretm & Rick_S

April 14, 2010
by Rick_S
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Odd, I thought of that but your second photo appeared to have both grounds common?? Anyway, Glad to hear you got it functional!!

Rick

April 14, 2010
by carlhako
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Yup it looks like its hooked up but if you look behind the green & green/white wires near the mcu you can see the copper end poking its head out wondering where it should touch to short something out.

The reason for the chip not running, it actually was but the code to init the uart was commented out so nothing would output. I had 2 pins around the wrong way running to the max7219 so nothing was lighting up on the led display. geez spend hours on these crazy little things.

Its all running and happy now im finishing off the case will post a pic when its done.

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