ESP8266 Community Forum

- Fri Jul 03, 2015 2:53 pm #22383

I'm too lazy to read upthread. Have you tried a snubber diode across the relay coil? That eats up the reverse spike generated by the collapsing field when the relay is switched off.

No problem:)

I use these cheap 4x relay modules off of ebay/aliexpress with the blue songle relays, apparently they have a snubber diode.

- Sat Jul 04, 2015 12:02 pm #22433

I use these cheap 4x relay modules off of ebay/aliexpress with the blue songle relays, apparently they have a snubber diode.

Ah. Interesting. Yes I see the diodes. I have a couple of these boards too but haven't tried them yet.

So, when one of these relays turns off, your ESP8266 resets?

The only possibilities I see are:

[1] - some sort of disruption or impulse on the power to the ESP8266
[2] - field collapse of the relay causing interference, possibly through the reset


#1 is the most likely culprit I suspect. You can try diagnosing #1 with a scope on the ESP8266's power line, or you can try to reduce possible effects by trying better power supplies, adding more power filtering at the ESP, dedicated 3.3v regulator for the ESP, even trying separate power supplies.

I still have a hard time believing that interference through the reset pin is the issue, but I haven't done any specific tests for this. You can try separating the ESP and relay board by a meter or more, you can even try removing connections between the relays and the ESP, then using an external jumper or switch to energize the relay, to see if the effect is still there. And you can add stronger pullups to reset of course.

Bonne chance.

- Wed Jul 08, 2015 9:44 am #22771 I had similar reset issues (or suspected reset issues)
In one case switching on a load caused the UART to send garbled data. In another case the CPU got stuck. I had to toggle the RST pin to revive the board. I used to use a reed relay to switch on a heating element.

As mentioned in previous posts, ESP is highly susceptible to voltage fluctuations. Most of my issues were solved on breadboard by a large cap (470u 10V) across the Vcc & Gnd (as close to Vcc as possible) and 100nF ceramic.
The clatter of the reed (similar to the arcs on your relay) might be the cause. The problem disappeared entirely when I switched to solid-state design.

Try soldering these two caps to the ESP board and see whether the problem persists.
For RST you can pull up the pin with a 4k7 resistor to Vcc

- Sun Aug 23, 2015 7:17 pm #26919 I am also having the same issue and I am using ESP8266 ESP-12 along with a similar 2 relay board as shown by "iothing". The module resets if I touch with multimeter, screwdriver or any other conductive material. I have tried using different supplies but problem persists. Also have tried with different capacitors and pull up combination but no success. Somebody mentioned about cutting the RST wire. Has anybody tried this on ESP-12? I don't really want to cut this connection since I want to use reset. I will try to connect the mains earth with the ground of my supply and see if it solves. Really frustrating!