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  • NODEMCU Lua ESP8266 With Real Time Clock (RTC) & EEPROM

    Em... This post says that one could use the onboard RTC. That seems like a good option to me. However, this post also says that the onboard RTC is not a good option, because the chip operates at various frequencies. Why does operating at various frequencies cause a problem with using the onboard RTC?I guess what's meant is that you need to power the whole chip in order to keep the RTC running; however, I think there is a way to run the onboard RTC without powering the whole chip: the VDD_RTC pin. I haven't read the datasheet yet (just looked at a schematic), but it seems that if you supply power to that pin, then you can run the RTC without powering the whole chip. The WeMos D1 Mini does not connect the VDD_RTC pin though (this might be true for many other ESP8266 boards as well...). See…

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    Em... This post says that one could use the onboard RTC. That seems like a good option to me. However, this post also says that the onboard RTC is not a good option, because the chip operates at various frequencies. Why does operating at various frequencies cause a problem with using the onboard RTC?I guess what's meant is that you need to power the whole chip in order to keep the RTC running; however, I think there is a way to run the onboard RTC without powering the whole chip: the VDD_RTC pin. I haven't read the datasheet yet (just looked at a schematic), but it seems that if you supply power to that pin, then you can run the RTC without powering the whole chip. The WeMos D1 Mini does not connect the VDD_RTC pin though (this might be true for many other ESP8266 boards as well...). Seems like it would be a good idea to hack in a connection. Perhaps, such a hack would make for a good Instructables article?Ultimately, there must be some reason that Espressif included this feature. It'd be nice not to have to use another chip (+ break out board) to do a function that the ESP8266 already has.

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