search

Heltec-Aaron-Lee / WiFi_Kit_series

Arduino source codes and toolchain for WiFi_Kit_series made by HelTecAutomation.
GNU Lesser General Public License v2.1
766 stars 308 forks source link

Using 5V Source from Board break serial/usb interface #106

Closed b3ster closed 4 years ago

b3ster commented 4 years ago

Hi,

I hope someone can explain the following behaviour and may help me to figure out whats going wrong.

Setup:

If I have something like a sds011 attached to the board via RX/TX - uart2 (Pin 16/17) I'm not able to connect to the board via REPL anymore (uart0 / usb), just get the feedback that a serial connection ist already established and this should be closed first. I#m wondering as I believe that uart(0) and uart(2) should be separate, how can one affect the other ? Thank you very much for your help :)

b3ster commented 4 years ago

I have found the Solution on my own, may this information help someone in the future: -> dust sensor sds011 (~70mA @5V) can not be used with the provided 5V from the heltec board, this causes the serial/usb interface to crash. Even if the main process is still running and the code is executed. So serving 5V from an external source solve the issue for this sensor. Would be nice to know what are the official specs for the provided 5V source from heltec board?