ESP8266 Developer Zone

Re: MODEM_SLEEP_T and system idle task

2017-11-17T10:19:53+08:00

Or, if it is really due to waiting for DTIM, is there a way to check, or to set a timeout? Or is this all in the sdk, and not accessible by developers?

Statistics: Posted by andrewtinkers — Fri Nov 17, 2017 10:19 am

Re: MODEM_SLEEP_T and system idle task

2017-11-17T01:27:28+08:00

I see it go into DTIM mode later actually. I attached a oscilloscope capture. There is a steady modem on period (RX I guess?) and then later it goes into DTIM, which is characterized by 15mA base, with 60mA spikes at a regular interval. I'm trying to figure out what the long 60mA bit is. This tail is always after a successful http transaction. And sometimes it is 500ms long, sometimes it can be as long as 10 seconds. I'm trying to figure out why, and how to make it consistent.

Statistics: Posted by andrewtinkers — Fri Nov 17, 2017 1:27 am

Re: MODEM_SLEEP_T and system idle task

2017-11-16T16:00:56+08:00

Maybe because of the idle task, but the more likely reason is the DTIM of your router.

Statistics: Posted by Her Mary — Thu Nov 16, 2017 4:00 pm

MODEM_SLEEP_T and system idle task

2017-11-16T05:06:11+08:00

In the documentation, MODEM_SLEEP_T seems like a great way to keep the wifi connection alive, yet still saving power.

However, I see some indeterminate behavior:

Most of the time, after a http request, I see the modem turn off, and the current draw drops from ~60mA to ~15mA within a second. And then there are short keep-alive connections later. This is expected.

However, sometimes after the http request, the modem stays on for 5 seconds, 10 seconds, even minutes. What determines this? Is it because we haven't hit a system idle task yet? If so, is there a way to debug which task is executing and preventing the system idle task?

Thank you!

Statistics: Posted by andrewtinkers — Thu Nov 16, 2017 5:06 am