I've now connected my board (from the same supplier) to a 3.3V supply. It is drawing 10.8mA in deep sleep. The red LED is drawing 1.5mA so I expect most of the remainder is being drawn by the UART bridge and perhaps by back-powering of the regulator. Anyway with 10.8mA being drawn, the batteries sho...

I've just tried writing 60 bytes to flash and timed it using the micros() function (before and after). It took 212μs (including some time taken by the 'micros' function calls, but excluding opening of file). I wonder if it may sometimes take longer, such as if the filing system sometimes needs to re...

If your booster is getting alarmingly hot it's not going to be a small current from your batteries.

Do you have something else such as a display connected?

Kazuya91 makes a good point about the AMS1117 regulator wasting current. The datasheet says the quiescent current is typically 5mA, possibly 11mA (when the voltage drop is 1.5V). As you are now using the 3V3 pin, hopefully there will be no wasted current through the regulator, but it's possible ther...

The Vin pin goes to the input of the low drop-out (LDO) regulator. The drop-out voltage (input to output differential) for that regulator is in the range 1.0V to 1.3V. So the regulator needs a supply to the Vin pin of at least 4.3V, possibly 4.6V. You need to use the 3V3 pin to avoid the regulator, ...

Thanks for the information Angus.

I suggest we now treat this issue as closed.

Thanks Sprite,

I was expecting anything that compiles for an Arduino should compile for the ESP32. I still think that should be the case (unless impossible due to hardware differences).

According to Wikipedia (here) in a standard library for C it should be tgamma, not gamma.

The datasheet says the control inputs are TTL compatible. That means anything over 2.0V should be recognised as 'high'. So I would say that there's no need for a MOSFET circuit.

BTW: as the 'on' resistance of each switch is about 4Ω, I don't understand how this device can do level shifting.

Many thanks.

So there is quite a large number of extra 'reserved words' when compiling for an ESP32. I was expecting only the usual C++ reserved words and the Arduino extras such as "delay".

When I compile this code within the Arduino IDE . . . . float gamma; void setup() { // put your setup code here, to run once: } void loop() { // put your main code here, to run repeatedly: } . . . . I get the warning message "float gamma redeclared as different kind of symbol". I don't get the warni...