MCP342x

A Rust crate for interfacing with the MCP342x ADC.

dependences

• log
• esp_idf_hal::i2c
• esp_idf_hal::delay::BLOCK

Usage

1. declare use mcp342x

use mcp342x::MCP342X;

2. decalre i2c

let i2c = peripherals.i2c0;
let sda = peripherals.pins.gpio0;//declare sda pin
let scl = peripherals.pins.gpio1;//declare scl pin
let config = i2c::I2cConfig::new().baudrate(100.kHz().into());
let mut i2c = i2c::I2cDriver::new(i2c, sda, scl, &config)?;

3. instantiate

Argument of new() is device address. 7bits device address is 0b110_1xxx. xxx is selectable. datasheet(P.21,Table5-3) or table below. For example, if adr0 is high and adr1 is low, slave address is "0b1101100".

let adc =MCP342X::new(0b1101000);

I²C Device Address Bits			Logic Status of Address Selection Pins
A2	A1	A0	Adr0 pin	Adr1 pin
0	0	0	Low	Low
0	0	1	Low	Float
0	1	0	Low	High
1	0	0	High	Low
1	0	1	High	Float
1	1	0	HIgh	High
0	1	1	Float	Low
1	1	1	Float	High
0	0	0	Float	Float

4. Get voltage

After instantiate, you can get voltage data as f64 using read_and_convert_adc. You can select channel, samplerate, pga.

Argument-num:

1. I2C
2. channel
   • 1, 2, 3(MCP3424 only), 4(MCP3424 only)
3. sample rate
   • 12, 14, 16, 18 bit
4. pga
   • x1, x2, x4, x8

let voltage=adc.read_and_convert_mcp342x(&mut i2c,1,16,1)?;  //chanel=1,16bitmode,pga=x1

Advenced use

You can get raw data(2 or 3 bytes) from mcp342x using read_mcp3424() and convert raw data using read_and_convert_adc(). See script if you know details.

Testing environment(2023/10/12)

software

• WSL2 (Ubuntu 20.04)
• esp-idf-sys = { version = "=0.32", features = ["binstart"] }
• esp-idf-svc = { version="=0.45", features = ["experimental", "alloc"] }
• embedded-svc = "0.24"
• log = "0.4"
• anyhow = "1"
• embedded-hal = "=1.0.0-alpha.9"
• esp-idf-hal = "0.40.1"

hardware

• M5Stamp c3 Mate
• mcp3424