ESP8266 Community Forum

- Tue Jun 30, 2015 6:04 am #22049

Paul, that is good, thank you!

Unfortunately this part would be the "show-stopper" for many applications:

Since my ESP-01 boots before the sensor device ever sends a HIGH, this works very well.

I had the same thought and wondered what to do in that case - Any ideas? Keep my circuit and delay powering the sensor or is there a better circuit? I'd like to find a solution that would work in both scenarios.

- Tue Jun 30, 2015 8:10 am #22055 I was thinking yes a delay might be necessary. Could be as simple as resistor/cap/transistor but I don't have a circuit handy.

- Wed Jul 01, 2015 4:40 pm #22195

This circuit seems awfully complicated to me. I'm not an electrical engineer, but from what I understand you just want to invert logic levels. Why don't you just use a simple transistor inverter or any standard NOT, NAND or NOR gate from the 74xx or CD40xx logic IC series?

Sounds awesome. Please post the circuit so we can take a look.

I'm too lazy to draw one, but luckily it's the most basic transistor circuit & there are plenty examples available
Any of these should work: https://en.wikipedia.org/wiki/Inverter_%28logic_gate%29
The "NMOS inverter" or "NPN resistor–transistor logic inverter" are most commonly used. Resistor values are not too critical, 4k7-10k would be ok.