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By vettett15
#206545
Hello, I received an Arduino Pro Mini and FTDI cable... Setup the IDE per the website recommendations and then uploaded the blink code just to make sure everything was working. Code uploaded fine, had it running for awhile and when i came back the green LED was not coming on any longer and had just a solid red light (power on).

I unplugged the FTDI cable, plugged it back in, tried to upload the code and kept getting the "avrdude stk500_getsync() not in sync resp=0x00 arduino uno" error. Tried all sorts of different solutions that didn't work. Finally ran across one example where the guy said to switch the board in the IDE to the "Arduino Duemilanove or Diecimila"... Did that and now it works... What is going on?
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By TS-Mark
#206579
Hi vettett15,

Which version of the Pro Mini and FTDI Cable do you have? Most likely, you had the wrong board definitions selected when you got the "avrdude stk500_getsync()" error. There are two versions of the Pro Mini (5V/16MHz and 3.3v/8MHz) so if you had the wrong option selected (Arduino defaults to 5V/16MHz), the oscillator speed would be off and not in sync. Double-check you had the right board and voltage/oscillator speed selected.
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By vettett15
#206581
I have the 5v/16mhz version. Selections were correct and I had been uploading to the arduino fine over a period of time. Ask of a sudden I can't upload to it any longer and the only fix was changing the arduino board as mentioned.
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By TS-Mark
#206610
Interesting. I have never heard of that fix or of these boards getting into that state before. Did you by chance select the "ATMega168 5V/16MHz" option at any point? That may be what caused the issue initially. After you uploaded to the board as "Arduino Duemilanove or Diecimila", did that fix the issue permanently or do you constantly need to upload to the board as that alternate definition? Finally, I'm not really sure what is causing the issue here so can you please take a few photos of your board(s) and how you are connecting them to your computer and attach them to your response? Please do your best to make sure they are clear and well-lit. Thanks!
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By vettett15
#206713
Nope, never changes it to the ATMega168 5V/16MHz. It did fix it permanently for my first board. I then made a second copy with the same arduino pro mini (bought 2) and had it working for an hour or so with the same settings and then all of a sudden it stopped working... I have no idea what is going on here
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By vettett15
#206714
Tried two different FTDI cables, doesn't seem to make a difference... Something is happening with the boards and it occurs while the arduino is running the code. It seems to start when i have it running the code for awhile, i close the serial monitor and some time later i notice the green LED goes away. When i try to re-upload i get the sync error.
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By vettett15
#206722
Here is a quick overview of my setup (see picture): A1335 sensor is hooked up to the Arduino through a SPI bus and the MCP4725 through a I2C bus. The headers next to the A1335 sensor allow me to interface with the SPI bus to program the sensor. Note that I do that programming prior to the Arduino being present.
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By TS-Chris
#206751
Hi vettett15.

It could be any number of things causing issues but it's impossible for us to tell what direction to look. You might try running the Pro Mini's off your assembly first, then connecting pins up one by one until you begin seeing troubles again. It could be something as simple as a bad setting in your computer or something more complex like a intermittent short circuit in your PCB.
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By TS-Mark
#206752
Chris' recommendations here are great. I have two other thoughts about this issue. First, how are you powering the other components in this circuit? Are you running them from the Pro Mini's Vcc pin? The voltage regulator for the Pro Mini can only source up to 150mA so if you have the other two components running off that pin along with the Pro Mini, it might be overtaxing the regulator and causing it to possibly go into thermal shutdown. The fact that it's locking up after running for a period of time kind of points to that. An alternative would be to use the RAW pin with a regulated 3.3 or 5V source.

The other thought is if you are opening up a serial terminal while the code is uploading or something similar to that. This is much more unlikely since that issue usually crops up on boards with an IC that has a built-in USB to serial converter like the Pro Micro.
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By vettett15
#206755
Thanks for the replies guys.

Chris, not sure what you mean by powering it off the assembly first and then connect pin by pin.

Whenever this has happened I've been powering everything off of the usb ftdi cable thru the arduino. The arduino is connected to the boards power plane thru the vcc pin. The other two devices besides the arduino should only be pulling 30mA each.

I attached the schematic. I don't get why it doesn't work one night and then the next morning it does. I know it's not the cable because when the one board wasn't working I switched to another board with the same cable and it works fine.
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By TS-Chris
#206805
Chris, not sure what you mean by powering it off the assembly first and then connect pin by pin.
What I meant by that was to disconnect the Pro Mini from the rest of your assembly and power it through the FTDI cable.
If it's accepting code and running, then start connecting the Pro Mini to the rest of your circuit pin by pin checking to make sure everything is working between each connection.

You'd probably want to start with ground, then power, then add I2C then SPI. I suspect you may have an intermittent short somewhere and this might help isolate where it is.
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By vettett15
#206944
So it looks like i may have an intermittent short... What's interesting is if i get the arduino in the mode where i can't upload to it, I unplugged the arduino from the circuit card, plugged it back in and then it works again. Wonder what is causing that.

I let the device run for 3 days, checked it 1-2 days out and it was working fine. I come home tonight (3rd day) and the serial monitor is showing a bunch of parity errors and isn't reading from my magnetic sensor any more... I unplugged everything but the magnetic sensor, hooked it up to the development kit from the sensor vendor and the sensor is working fine. I plug a new arduino in and it works fine. Not sure what can cause an error on the arduino spi bus? The "bad" arduino allows me to still upload to it so i uploaded the blink program and it works fine... Thoughts?
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By TS-Chris
#206970
I plug a new arduino in and it works fine. Not sure what can cause an error on the arduino spi bus? The "bad" arduino allows me to still upload to it so i uploaded the blink program and it works fine... Thoughts?
Unfortunately we're not really sure what's causing your trouble. If it was just a single Pro Mini, we'd chalk it up to a defect in the Pro Mini, but two of these have failed on you now and we don't see Pro Mini's failing like you describe. I really think it's something in your design or possibly your power supply that's causing the issues but I don't know where to advise you to look. You might try bread boarding the circuit to see if everything functions long term that way and if it does, it's got to be a problem somewhere in your PCB.