ESP8266 Community Forum

trackerj wrote:On the basic, it's nothing more than a clasic Li-Ion battery charger with RTC power monitor

Which RTC, Charger, regulator are you using? What are battery dimensions? Thanks.

wififofum wrote:

trackerj wrote:On the basic, it's nothing more than a clasic Li-Ion battery charger with RTC power monitor

Which RTC, Charger, regulator are you using? What are battery dimensions? Thanks.

RTC: any that have programable Alarm and INT out pin:
Used so far:
PCF8563
DS3231

Charger: MCP73831

REG: any LDO with over 300mA capabilities, like MCP1825

Battery, as I said, is just a poor one, probably a clone for a Nintendo DS Lite (at least this is what is written on it, don't remember how landed in my drawer and when, never had or seen around a NDS Lite ). Size is about 2.8x4.8x0.5 cm.

Does the ESP8266 not include a built in RTC? If so it would most likely be based on the Cadence IP defined here. Assuming that it exists, and that the on-board RTC is powered from the same source as the main processor, does this not make an additional RTC redundant?

Hi Andy,

Glad to see you here !

For the ESP8266 RTC, unfortunately, Espressif never give much details about it. In fact, RTC means here more Real Time Counter than Real Time Clock. Although, I didn't verify myself, some people reported that this counter is even reset to zero when waking up from deep-sleep.
Also, most softwares are only using the SDK function system_get_rtc_time(), but not much more, although there are some other functions to access registers, but since no docs are provide for them, it is difficult to run in the fog.
I hope that with ESP32 things will become clearer and that we can get a real RTC with a VBat pin.