ESP8266 Community Forum

- Thu May 21, 2015 9:18 pm #18130 Deep sleep (<10uA) is very impressive. May I ask whether ESP8266 can remain connected to the Access Point even in deep sleep?

The ESP-Wroom module datasheet has the following line;
- Wake up and transmit packets in < 2ms

Does it mean that the modue can wake up from deep sleep and starting sending out packets through the Access Point within 2ms?

- Thu May 21, 2015 10:22 pm #18132

Deep sleep (<10uA) is very impressive. May I ask whether ESP8266 can remain connected to the Access Point even in deep sleep?

No, the device is basically off in deep sleep, only the on-board RTC keeps running. It will do a full reset on wake-up.

Does it mean that the modue can wake up from deep sleep and starting sending out packets through the Access Point within 2ms?

While that number might technically be true, don't expect the device to be fully connected after 2ms. That number most likely means, that the ESP will send its first probe request after 2ms, from there it needs to wait for replies, begin association and finally request an IP via dhcp. While this process is pretty fast, it will take a lot longer than 2ms (in my very unscientific tests, the ESP started replying to pings approx. 1-2s after powerup).

- Thu May 21, 2015 11:30 pm #18133 Thanks for your helpful reply. What is the lowest current consumption the ESP8266 can be in when it is idle and connected to an AP? Is that a specific state to be in? Something like deep sleep?

- Fri May 22, 2015 12:26 am #18135 Moin,

I expect the startup to be faster if you don't do dhcp every time but most times to set the ip
directly.

I didn't tested it myself.

Cal

Get your modules here:

https://www.banggood.com/custlink/KvGGhGF4wG