ESP8266 Community Forum

- Fri Jun 15, 2018 9:23 am #76455 Lots of post about loosing connection but I can't find any that say "... because and the fix is...".

So, I have 3 01's with the little blue relay. The sketch is simple, connect as a fixed IP, start web server and wait for ".../on" [../off]. The wifi server is a RasPi 3B 30 ft away, so great signal. When I first set it up it ran for at least a week for without any problem - then all 3 failed. I checked the voltage and it was 4.6v, adjusted up to 5.02 and I'm back in business - for about 2 hrs. Now I can't get it to connect at all. Blue led blink blink blink blink.........

In looking at my sketch I had left several "Serial.print.." lines in. So my question is: If there is no serial connection what happens to the print lines? > null or > buffer (which fills up)? My thought is the latter because (now won't connect after power off) blue led blinking(delay 500) that if > buffer it's buffer overflow in to ?bios? area????

Enquiring mind

- Fri Jun 15, 2018 10:42 am #76456 As with everything, it could be anything; that's why there's no "... because and the fix is".

I checked the voltage and it was 4.6v, adjusted up to 5.02 and I'm back in business

You are aware that the ESP-01 (just like all ESP modules) runs solely on 3.3V?
It's important to have a solid and stable power supply that's able to deliver at least 500mA, but it really has to be 3.3V (+-10%) or the ESP will fail in the end.

Assumption is the mother of all f*ckups. At least: that's what I'm assuming.

- Fri Jun 15, 2018 10:46 am #76457

Lots of post about loosing connection but I can't find any that say "... because and the fix is...".

So, I have 3 01's with the little blue relay. The sketch is simple, connect as a fixed IP, start web server and wait for ".../on" [../off]. The wifi server is a RasPi 3B 30 ft away, so great signal. When I first set it up it ran for at least a week for without any problem - then all 3 failed. I checked the voltage and it was 4.6v, adjusted up to 5.02 and I'm back in business - for about 2 hrs. Now I can't get it to connect at all. Blue led blink blink blink blink.........

In looking at my sketch I had left several "Serial.print.." lines in. So my question is: If there is no serial connection what happens to the print lines? > null or > buffer (which fills up)? My thought is the latter because (now won't connect after power off) blue led blinking(delay 500) that if > buffer it's buffer overflow in to ?bios? area????

Enquiring mind

Nope, serial uart output data is volatile (I.e. In RAM) not persistently stored anywhere. Power off/on would clear any buffered serial out data. If you were outputting HUGE amounts of data the serial speed will be such that it slows down the ability to service other interrupts, which might cause unreliability (at least that is what I have seen in experiments with interrupts and serial out). I've seen cases where the timer interrupt gets suspended and millis/micros output stops changing.

- Fri Jun 15, 2018 11:44 am #76459 https://smile.amazon.com/WHDTS-ESP8266- ... elay+board

Requires 5V in - has onboard 3.3 reg.
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As to Serial.print - I had to ask