ESP8266 Community Forum

- Mon Feb 08, 2016 6:42 am #40680

I thought the ESP could measure the voltage of the battery that feeds it, but I could be wrong.

ESP8266 internal ADC Max input Voltage is about 1V. You need a voltage divider for any Voltage bigger than that:

You can read more about in this ESP8266 Internal ADC Blog Post

ESP8266 MPDMv4 AC MAINS Dimmer Home: http://esp8266-projects.com/2016/04/mpdmv4-mains-dimmerswitch-html/
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- Mon Feb 08, 2016 7:25 am #40685

I thought the ESP could measure the voltage of the battery that feeds it, but I could be wrong.

Yes, but the only analog pin must be used either for voltage measurement or sensor pin. In my case I have an analog sensor already using the pin..

- Mon Feb 08, 2016 8:04 am #40691

Your Setup with ATtiny85 seems a bit overkill to get additional ADC.
You can simple add an MCP3008 on an SPI provide by ESP and you get 8 input ADC at more than 75ksample.
There is also some I2C bus ADCs, such MCP3021 or MCP3421 which provide 1 input, 8-to-1 analog multiplexer such CD4051 can be added to them consuming 3 address more GPIOs.

Thank you Martin. Those babies do look juicy, something to play with in the future.

Wanted to get your take on the price point, guys. Even a basic chip from above was at around $0.85 in a 10 unit lot on Ali. Many go well above that. Given that I can get a full attiny85 breakout board for $1.00-1.15 delivered, I'm really on the fence here. Sure, 3 adc pins vs 8 or 16 argument stands. Plus precision differences. And I have a bunch of attiny85 already But other than that, am I missing anything else?

Having spent the last 15 or so years in enterprise software, having 2 boards figure out a way to communicate is not an issue. The electrical part is a new world to me though, and I really appreciate how helpful the esp8266 community has been so far

- Mon Feb 08, 2016 9:18 am #40701 Hi Andrew,

I think this is the question if you are developing a “product” or need to quickly hack together a solution with what have handy. If the latter and your world is s/w rather than h/w then quick overkill with programming two controllers instead of one looks justified

Krzysztof