ESP8266 Community Forum

- Fri Apr 19, 2019 3:21 am #81896 If the problem is the slow start of the power supply you may be able to work around that by slowing down the rise of the reset signal so that it goes high after the power supply has reached working voltage.

To achieve that you could put extra capacitance from the reset line to ground. I'd suggest putting a 25uF capacitor to see if that worked.

- Fri Apr 19, 2019 3:30 am #81897 I think for that to work best, you'd also have to add a resistor between the capacitor and the reset pin, so the capacitor drains more slowly. Then you'd probably need a smaller capacitor and the strain on the power supply is less.

- Sat Apr 20, 2019 6:28 am #81923 I don't think any extra resistor is necessary or even desirable.

The reset line has a 12K resistor pull up to 3.3V and a capacitor of unknown value to ground. So unaided when power is applied the capacitor charges up 'slowly ' through the 12K resistor and when it crosses threshold the reset is released and the chip starts up.

By adding a capacitor from the reset pin to 0V all one is doing is increasing the time constant and delaying when the voltage crosses the threshold.

There is no stress on the supply as the 12K resistor limits the charging current already.

- Sat Apr 20, 2019 6:58 am #81924 Why not confirm it starts OK with the lab supply and if it does just buy another PSU?