hello_world.c
New member
My application couldn't be simpler so I'll just describe it:
- Teensy 3.2 supplied with 5.1V on Vin
- UART level shifter (MAX3232) connected to RX1/TX1 and powered by Teensy's 3.3V line
- Pin 2 as output connected to a WS2812B LED matrix data input via series resistor
This has been running for weeks but now something strange occurs. When I power everything, the Teensy is suddenly trying to draw >800 mA and the voltage drops.
However, when I have the USB port connected to my computer, or even a 5V-powered USB hub without connection to the computer, this doesn't happen and everything works normally! This regardless of whether I apply the external power at Vin or not.
For testing I've isolated pin 2 and whether or not it's connected to the LED matrix doesn't make any difference. I've also measured the current to the LED matrix and it is not causing the issue.
Any idea where to look? Could the USB chip on the Teensy be the culprit?
- Teensy 3.2 supplied with 5.1V on Vin
- UART level shifter (MAX3232) connected to RX1/TX1 and powered by Teensy's 3.3V line
- Pin 2 as output connected to a WS2812B LED matrix data input via series resistor
This has been running for weeks but now something strange occurs. When I power everything, the Teensy is suddenly trying to draw >800 mA and the voltage drops.
However, when I have the USB port connected to my computer, or even a 5V-powered USB hub without connection to the computer, this doesn't happen and everything works normally! This regardless of whether I apply the external power at Vin or not.
For testing I've isolated pin 2 and whether or not it's connected to the LED matrix doesn't make any difference. I've also measured the current to the LED matrix and it is not causing the issue.
Any idea where to look? Could the USB chip on the Teensy be the culprit?