I bought my first microcontroller and a few shields for it, and they arrived yesterday. I was so excited about tinkering with them that I completely forgot about all safety precautions and think that I might have broken them.

The microcontroller is the Wemos D1 Mini and the shields are:

I downloaded the Arduino IDE and installed the related libraries for ESP-8266 support and the shield specific libraries, and then compiled and uploaded sample code for operating the OLED and the SHT30, but nothing seemed to happen.

Serial out was just printing "Error" from the sample code, indicating that the sensor didn't respond on I2C, and the OLED display was just black. I then tried moving the shields a bit and disconnecting and reconnecting them while still powered. I'm quite sure that I connected the shields the correct way, but I can't be completely sure.

I then tested only the OLED shield, only the SHT30 shield and only the TFT shield, but I couldn't manage to get any of them to work. I managed to get about 10 readings from the SHT30, but after that it started erroring again. The TFT screen also displays white only when trying its example code.

So here are the main questions:

  1. If I accidentally placed some shield upside down or rotated it, so that the pins were incorrectly, could this have killed the pins for example from the 5V pin touching something it shouldn't?

  2. Could I have shorted some pins with my fingers by touching them while powered?

  3. Could I have damaged the shields/microcontroller by disconnecting/reconnecting them while powered?

  4. Is it possible that the components have been damaged from the start before I touched them?

I will probably have to buy new components and be more careful this time.


1 Answer 1

  1. It seems that the MCU board doesn´t have a reverse protection with an diode. So it is possible that you kill the board (other solution is, that you put +5 V on a GPIO of the MCU).
  2. I don´t think that you get a good connection with your fingers, so I think that wasn´t the issue (maybe ESD?).
  3. Very unlikely. I disconnect/connect all devices to my MCU, while the MCU or the device is powered.
  4. This is an option with every delivery.

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