I am building a quadcopter using Teensy 3.1, MPU-9150 sensors, NRF24L01 radio and Pololu voltage converter. After initial success Teensy has died or so I thought.
Teensy is powered through a 3.3v converter. I've cut the VUSB - VIN pads, but I've soldered a wire from VUSB to the converter input to be able to power it from both battery pack and USB and reprogam it using USB. 3.3v from is connected to Teensy VIN pin.
Having soldered everything together on an universal pcb, I've tested it, first by uploading standard blinky, then by testing the sensors. Both seemed to work. Bliny blinked and sensors read good values. The after a while it simply stopped. A tried plugging it off and on again. It blinked for a second or two then went off again. I repeated it for a few times, but then it simply wouldn't even start. PC detected no device connected either.
I've read quite a few topics about dead Teensys and tried measuring voltages and checking for shorts. VIN reads steady 3.31v, the 3.3v pin reads about 3v, but program pin reads 0v. I checked the resistance to ground an it was about 600ohm. I've read that there could be some residue from soldering so the next day I've thoroughly washed everything in denatured alcohol and dried it. There was more conduction between PROG and GND. I plugged the Teensy uploaded standard blinky and it worked... for about a minute, then it died again. Plugging it off and on again didn't help.
This time when I measured PROG pin it read anything from 0 to 3v, so I guess it switches between these two very rapidly. What bothers me most that one time it works, the next it doesn't. Sometimes when I plug it while I hold the reset button it connects to the PC, successfully uploads a program and stops working.
Yesterday I cleaned it again using more denatured alcohol and a toothbrush. After letting it dry for the night I plugged it in and miraculously it began working. I managed to work with it for well over 8 hours, after that it died on me again.
Since then I haven't managed to get it working. Normally I'd try desoldering everything and check if it's one of the other devices that might be causing problems but in this case it's so tightly soldered that it's beyond my abilities. If it simply didn't work at all I would assume I had made an error somewhere while soldering but in this case I have no idea what could be the cause of this weird behaviour.
Teensy is powered through a 3.3v converter. I've cut the VUSB - VIN pads, but I've soldered a wire from VUSB to the converter input to be able to power it from both battery pack and USB and reprogam it using USB. 3.3v from is connected to Teensy VIN pin.
Having soldered everything together on an universal pcb, I've tested it, first by uploading standard blinky, then by testing the sensors. Both seemed to work. Bliny blinked and sensors read good values. The after a while it simply stopped. A tried plugging it off and on again. It blinked for a second or two then went off again. I repeated it for a few times, but then it simply wouldn't even start. PC detected no device connected either.
I've read quite a few topics about dead Teensys and tried measuring voltages and checking for shorts. VIN reads steady 3.31v, the 3.3v pin reads about 3v, but program pin reads 0v. I checked the resistance to ground an it was about 600ohm. I've read that there could be some residue from soldering so the next day I've thoroughly washed everything in denatured alcohol and dried it. There was more conduction between PROG and GND. I plugged the Teensy uploaded standard blinky and it worked... for about a minute, then it died again. Plugging it off and on again didn't help.
This time when I measured PROG pin it read anything from 0 to 3v, so I guess it switches between these two very rapidly. What bothers me most that one time it works, the next it doesn't. Sometimes when I plug it while I hold the reset button it connects to the PC, successfully uploads a program and stops working.
Yesterday I cleaned it again using more denatured alcohol and a toothbrush. After letting it dry for the night I plugged it in and miraculously it began working. I managed to work with it for well over 8 hours, after that it died on me again.
Since then I haven't managed to get it working. Normally I'd try desoldering everything and check if it's one of the other devices that might be causing problems but in this case it's so tightly soldered that it's beyond my abilities. If it simply didn't work at all I would assume I had made an error somewhere while soldering but in this case I have no idea what could be the cause of this weird behaviour.