Arduino Compatible Pro Micro (HCDVBD0013)

pgrunwald
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Joined: Wed Jul 13, 2016 2:06 am

Re: Arduino Compatible Pro Micro (HCDVBD0013)

Post by pgrunwald » Wed Jul 13, 2016 2:12 am

Hi - I just built a headtracker (HCKITS0021-HCKITS0021C) with the EDTracker rev 2.0 board.

The red LED between RX1 and GND flashes for 5-10 seconds when I connect a USB cable (multiple tried). VCC->GNDreads ~1.24V to all three grounds. RAW->GND reads 1.7V. With drivers installed, I don't see anything in Windows 10 device manager and cannot connect to EDTracker GUI.

I have checked for cold solder joints and bridges, everything looks clean.

Please advise.

Thanks,
Paul

andrew
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Re: Arduino Compatible Pro Micro (HCDVBD0013)

Post by andrew » Wed Jul 13, 2016 8:56 am

Thanks for the information although there are a few things that have a little me confused as to what the problem could be...
The red LED between RX1 and GND flashes for 5-10 seconds
I believe the LED you are referring to is the power LED. It's connected permanently across the 5V (VCC) supply and so shouldn't be able to flash. Is it flashing as a steady rate, or is it flickering/not flashing at a constant speed?

Also when you first connect the USB cable do you see any of the amber LEDs flash?

VCC->GNDreads ~1.24V
1.24V is too low for anything to work and I would expect it to need at least double that before any LEDs will even begin illuminate. I assume you are measuring this voltage after the red LED stops flashing? If so then it looks like power is initially there and then drops out after a few seconds. There's a couple of reasons that come to mind why this could happen:

First is a partial short somewhere that's causing the 5V regulators on the Pro Micro to overload. When you connect the USB, and assuming you can get access to it, can you check if this regulator gets hot? It's a small black square component with 5 pins and is located between the two big square orange capacitors.

The second and more likely possibility is that the computer is removing the 5V power from its USB port because it either cannot recognise what is attached to it, or your Pro Micro is drawing too much power from the USB port. If so the easiest thing to try is another USB cable (if you have one) in case it's a bad cable. This does happen. If this doesn't fix the problem then as above it could still be pointing to a partial short circuit. Whilst the LED is illuminated check that nothing on either the Pro Micro or the accelerometer is getting hot to the touch.

I can't connect this forum account to an order so I don't know which accelerometer you purchased with the bundle. If my suggestions don't resolve your problem could let me know if it was a GY-521 or an MPU9250?
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pgrunwald
Posts: 3
Joined: Wed Jul 13, 2016 2:06 am

Re: Arduino Compatible Pro Micro (HCDVBD0013)

Post by pgrunwald » Wed Jul 13, 2016 5:54 pm

andrew wrote:Thanks for the information although there are a few things that have a little me confused as to what the problem could be...
The red LED between RX1 and GND flashes for 5-10 seconds
I believe the LED you are referring to is the power LED. It's connected permanently across the 5V (VCC) supply and so shouldn't be able to flash. Is it flashing as a steady rate, or is it flickering/not flashing at a constant speed?

>>> It is flickering.

Also when you first connect the USB cable do you see any of the amber LEDs flash?

>>> No

VCC->GNDreads ~1.24V
1.24V is too low for anything to work and I would expect it to need at least double that before any LEDs will even begin illuminate. I assume you are measuring this voltage after the red LED stops flashing? If so then it looks like power is initially there and then drops out after a few seconds. There's a couple of reasons that come to mind why this could happen:

First is a partial short somewhere that's causing the 5V regulators on the Pro Micro to overload. When you connect the USB, and assuming you can get access to it, can you check if this regulator gets hot? It's a small black square component with 5 pins and is located between the two big square orange capacitors.

>>> Yes, it is getting very hot.

The second and more likely possibility is that the computer is removing the 5V power from its USB port because it either cannot recognise what is attached to it, or your Pro Micro is drawing too much power from the USB port. If so the easiest thing to try is another USB cable (if you have one) in case it's a bad cable. This does happen. If this doesn't fix the problem then as above it could still be pointing to a partial short circuit. Whilst the LED is illuminated check that nothing on either the Pro Micro or the accelerometer is getting hot to the touch.

I can't connect this forum account to an order so I don't know which accelerometer you purchased with the bundle. If my suggestions don't resolve your problem could let me know if it was a GY-521 or an MPU9250?
>>> MPU9150

I'm going to pull off the Pro Micro and check for shorts. I will keep you posted.

pgrunwald
Posts: 3
Joined: Wed Jul 13, 2016 2:06 am

Re: Arduino Compatible Pro Micro (HCDVBD0013)

Post by pgrunwald » Wed Jul 13, 2016 8:07 pm

I pulled off both the Arduino and the MPU9150. The Arduino worked fine stand alone. I put it on the tracker PCB and it also worked fine and programmed. When I put the 9150 on, it started failing again. I don't know if I can lift things again without starting to lose pads.

My original order was 548416ac7.

Thanks,
Paul

andrew
Site Admin
Posts: 791
Joined: Sun Aug 05, 2012 4:15 pm

Re: Arduino Compatible Pro Micro (HCDVBD0013)

Post by andrew » Thu Jul 14, 2016 9:12 am

Thanks for the information. If it's pulling the 5V power rail down then there must be a short on the MPU9150 somewhere. If it's a component on the module causing the short I'd expect it to be to be getting hot to the touch. You may want to try briefly connecting the USB cable and checking to see if any component on the MPU9150 immediately gets hot. This would at the very least help confirm there is a problem with the MPU9150. If no components are getting hot then it could just be a rouge piece of solder shorting somewhere. This does assume of course that your confident the MPU9150 is soldered to the EDTracker pcb in the correct orientation and position.

Failing this, I would suggest your best option would be to replace the MPU9120. We've not sold that module for quite some time but the MPU9250 we currently sell is a direct replacement.
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