ESP8266 Community Forum

- Fri May 15, 2015 12:35 am #17428 Hi,

The main drain on the battery takes place during transmission. On GitHub I notice that the release of the RSSI (Received Signal Strength Indication) functionality is getting closer.

A very handy feature would be to be to have control over the output power level to be able to set it at the minimum level dictated by the Received Signal Strength.

This will stop "wasting" unnecessary high RF power levels draining the battery when the ESP is located close to an WiFi AP that can be "reached" with low transmission power levels.

Would this be possible ?

Nicol

- Wed May 20, 2015 7:53 am #17951 Or, as an alternative, does ESP8266 API allow to turn off WiFi hardware (RF blocks) when not in use?

I am thinking of a client application that needs to monitor something happening on GPIO thus needs 8266 computing power, but would connect to the network only when a given event occurs. Such as an alarm on high temperature, intrusion, ...

- Wed May 20, 2015 8:52 am #17958 The ESP does allow RF components (modem) to be turned off in the NodeMCU API , using the wifi.sleeptype() command.
Using this functionality with the possibility to reduce the transmit power level would provide maximum control.

- Thu May 21, 2015 6:12 am #18052 Excellent. The documentation is being slowly built up about what each of the sleep modes actually does. Info are sparse, but can be located with a search engine

The same choice is available in the Arduino IDE/firmware/whatever. I understand that RF is disabled after the ESP8266 comes to life after a deep sleep. So it would be:

power up with RF active
go into a deep sleep mode
wake-up without RF
go into a deep sleep mode, maybe a different one that allows external communication

To my understanding, the whole process requires a strong firmware that handles multiple ways to go into deep sleep. It's not just like a toggle switch for RF.

Unfortunately there does not seem to be a way to reduce RF output power.