ESP32 Forum

Hi All,

I would like to ask if someone could have information about the power consumption for the ESP32 in Bluetooth mode, In the datasheet is good information about WiFi, but not for BT.

I am testing some examples for BT and WFI, they are within the IDF, I made come current measurements and I got around 150mA from the 5V Power supply, which is ok for wifi but not for BT in BLE mode.

As BT and WIFI are sharing the RF path, maybe this is the reason that the power consumptions is high for BT?

Any advice how to test BT in BLE mode...

Regards

Juan

Hi

I had the same measurements almost - around 120-130 mA. As of now only BTDM (Dual Mode, both classic and BLE) is supported and my assumption is that it is because of the bluetooth classic that current consumption is so high - but I do not know for sure. It could be nice if someone could confirm this.

Also, make sure to check how you configured your CPU. Running two cores at 240MHz can easily eat up 80mA or so. Using only one core at e.g. 80MHz should bring that number down a fair amount.

Would that be configured with make menuconfig?

Thanks

Yep, Component config -> ESP32-specific -> CPU frequency

And disabling one is also done in make menuconfig?

Thanks

ESP_Sprite wrote:Also, make sure to check how you configured your CPU. Running two cores at 240MHz can easily eat up 80mA or so. Using only one core at e.g. 80MHz should bring that number down a fair amount.

I did the down tuning of the CPU frequency to 80MHZ but still up around 100-110 mA.

How do you run only one core? Is it something that is configurable or how do you achieve that?

Yes, although I can imagine its location is slightly less findable. Easiest way is to disable 'Component Config -> esp32-specific -> Reserve memory for two cores'; this will also disable FreeRTOS multicore support and should keep the 2nd cpu clock gated.

Note that disabling the second CPU doesn't reduce current consumption as much as lowering the CPU frequency does.
At 80 MHz, with two idling CPUs the chip consumes 44mA (without any radios), and with one CPU it consumes 40mA.

ESP_igrr wrote:Note that disabling the second CPU doesn't reduce current consumption as much as lowering the CPU frequency does.
At 80 MHz, with two idling CPUs the chip consumes 44mA (without any radios), and with one CPU it consumes 40mA.

Ok, thanks for the updates.

So I guess what you are saying is .. it is all about the radio? What can be done about the radio to get the mA further down? Or do I just have to accept that using ble requires 100-110 mA during operation at 80 MHz, maybe 95-100 mA if I use a single core?

Thanks