[SOLVED] Reset pin with a NPN transistor

General
1

Mod edit (@harrisonhjones): Solution: Use System.reset() to issue a reset with code

Hello and Happy New Year to all :slight_smile:
I would like to ground the reset pin with a NPN transistor.
I need to reset the photon via Blynk app and dont have much room in my project for a relay. I though of using a transistor. Receive a HIGH from a digital pin to ground the reset pin.
Could someone tell me if a BC337 would do the job and if so, what resistor values to use.
Thanks in advance!

2

Do you actually need to do that via hardware or would calling System.reset() via a virtual pin suffice?

The problem with your approach will be that you’d need extra hardware to keep the transistor switched long enough for a proper reset, since your digital pin will fail to hold the required signal almost instantly.

3

That will suffice. Thank you. Give it a try soon.
I have accomplished it with a relay and works every time. Just wanted to save room.
So is that all is needed?
System.reset();

4

The switching speed of a transistor is magnitudes higher than that of a relay.

5 
BLYNK_WRITE(10)
{
  if (param.asInt()) {
    System.reset();
  } 
  else 
  {
  }
{

This didn’t work. I don’t think I’m writing the code correctly.

6

You want to use a virtual pin and try it without condition first

BLYNK_WRITE(V1)
{
  System.reset();
{
1 Like
7

2 posts were split to a new topic: Using transistor instead of a relay