If I make the esp_now_send to the broadcast address (FF FF FF FF FF FF) then the esp_wifi.close() is only 1ms still. I think the delay is if there is an incomplete esp_now send.

Would be nice to make an improvement on the esp_wifi_start() side of it because 8ms is painful there.

I will look at the ESP-IDF to see if it improves things, but automatic light sleep won't work here as I am using ESP NOW and the timings of communications aren't as pre determined as with the DTIM WiFi situation involving an access point. I do need to be controlling the sleep directly and therefore ...

Thanks Angus. Automatic light sleep does look like a good solution. I'll have to look at how much pain is involved in transitioning across to ESP-IDF. It would be good to take advantage of the work I have done within Arduino though.

should be:

In my application, I am using light sleep and periodically waking up and using esp now. I want the time awake to be an absolute minimum. I use the following code: esp_sleep_enable_timer_wakeup(SLEEP_US); esp_wifi_stop(); esp_light_sleep_start(); esp_wifi_start(); For the first cycle, the esp_wifi_st...