ESP8266 Community Forum

- Wed May 17, 2017 6:56 am #66006 Hi All,

From ESP12e datasheet I can see there are two pins dedicated to IR 38KHz transmission, Can't find any manual on how to use it.

Does anyone knows how to make it happen?

IRPins_FromDatasheet.png

You do not have the required permissions to view the files attached to this post.

- Thu May 18, 2017 5:55 am #66034 There are two main methods to getting the 38Khz modulation for IR transmission.

First some libraries just bit bang in the foreground with delays to give the 38Khz.

Second is to exploit the capability to put out internally generated clocks onto specific pins 2 or 14). It uses the I2S word clock which can generate frequencies in the 10 - 400KHz range fairly accurately. This is the method referred to in the datasheet when it talks about pins supporting IR.

There is an example of the second method in the SDK but it is not brilliantly documented.

I also use the second method in my interrupt driven bit bang libraries as used in my IR blaster project. These allow turning on and off the 38KHz clock very efficiently. Details are at https://github.com/roberttidey/IRBlasterWeb Specifically the pin drivers are in the BitTX library