ESP8266 Community Forum

- Wed Jun 01, 2016 3:44 am #48373 Hi, +1 on martinayotte's comments. The outputs are rated at 12mA max so given V = I * R
R = V / I = 3.3V / 0.012A = 275 ohms.
The smallest pull up you can use is 275 ohms, it's not worth going that low and risking damaging the outputs. If 1K doesn't work, then you need to rethink the implementation. I'm not sure how your coding the button presses but it might be worth having a second look at the button 50mS later to make sure it's still pressed and not just a transient.

- Wed Jun 01, 2016 7:39 am #48392 I also tried with 100kΩ and 10KΩ resistors, seems to improve a bit, but still getting a lot of false reads if the ESP gets too close to the Contactor (like 10cm or so).

I don't have any capacitor at hand, but I will try as soon as I get one. How should I wire the capacitor ?

I guess I could code something smart to check if its a real trigger or not, but yesterday I tested some more, wrote a simple push button to add to a counter and display on the LCD and some weird things started to appear on the LCD, like a 4 digit number turned into a 8 one (I guess its a LCD positioning thing, nothing memory related).

I'll need to test some more, but I'll try to keep the solution to a hardware level for now.

- Wed Jun 01, 2016 8:01 am #48394

How should I wire the capacitor ?

As I said : in parallel with the switch.

- Mon Aug 15, 2016 1:59 pm #53006 Hey guys, it's been a while but I'm back with a few updates on the project, but still bugged by the same issue.

Since last time I've made a PCB and tested for a few days with success but only when powered by an external battery, Here are some images:




When the board is powered by any source of power other than the battery (via the breadboard power supply or a cell phone charger), every time the Electromechanical Contactor is triggered, it also trigger some other random input on the board, even when there are no wires between the Contactor and the Board, just by being on the same electric grid those issues occur.

I'm pretty new at this, I've tried what martinayotte said regarding the external pull-ups and decoupling capacitor, but I'm not sure if I understood him right, so here's a picture(bellow) of what I did (the capacitor is connected on only one of the switches(above), but since it still randomly triggers it, my guess is that it's not working, so I haven't placed it on the any other switches).