ESP8266 Community Forum

- Wed Dec 16, 2015 12:24 am #36546 Hello friends, I'm trying to decide on an external ADC module to use with the ESP8266. I will be making my own board and will program using the RTOS SDK.

Any suggestions for external ADC modules?

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- Wed Dec 16, 2015 12:41 am #36548 If you don't need high speed, MCP3421 is a quite nice and cheap ADC.

Example here: MCP3421 I2C ADC Driver example

Also used for the ESP8266 Analog Extension Board - AN1

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- Wed Dec 16, 2015 12:47 am #36549 There are lots of ADC chips. First thing you should do is to outline the specs your need for your application, such as:
- sample rate
- number of channels
- precision (bits/sample, noise)
- supply voltage (3.3V or 5V?)
- do you need a differential ADC?
- interface (SPI? I2C?)
- package type

These features will significantly narrow your choice of ADCs...

- Wed Dec 16, 2015 1:17 am #36551 Thanks for the replies, guys. TrackerJ - I was just reading your blog post about all this

I was actually thinking about MCP3021.

Don't need high resolution, don't need high speed.
Supply - like ESP - 3.3V. I don't think I need differential.

The main concerns are:
- Hooking it up to the ESP - i2c seems to be the answer here, as SPI is taken up by flash.
- Driver. Don't think there is one for RTOS SDK, but at least I can look off the Lua/Ardruino verions.

EDIT:
Oh, the one bell-n-whistle I would like to have is a built-in amplifier... MCP3421 has it, but MCP3021 does not

Some of my work