ADS129xx

Driver crate for the Texas Instruments ADS1292 24-bit 2-channel low-power analog front end for ECG applications.

This initial version supports the ADS1292 (for the most part), but it's a goal to support the ADS1291 and ADS1292R as well.

Contributions welcome!

Usage example

// spi: spi interface
// ncs: not-Chip-Select pin
// timer: timer, 500kHz timeout.

let spi_device = SpiDevice::new(spi, ncs, timer)?;
let mut ads = Ads1292::init(spi_device)?;

// start conversions
ads.cmd(ads129xx::Command::START).unwrap();
ads.wait(200)?; // Wait a while in between sending commands
ads.cmd(ads129xx::Command::RDATAC).unwrap();
ads.wait(200)?;

let mut stream = ads.into_data_stream()?;

let mut buf = [[ChannelData::default(); 2]; 10];

// Opens stream, sends RDATAC command to ads
let data_stream = ads1292.into_data_stream()?;
ads.wait(200)?;

// A buffer to read data into
let mut buf = [[Ads1292Data::default(); 2]; 2000];

for i in buf.iter_mut() {
    // some way of finding out NDRDY has been low since last read (preferably by an interrupt-set flag)
    while !data_ready() {} 
    // data_stream always returns data (for now), so we can unwrap here
    *i = data_stream.next().unwrap()?;
}
// Don't forget to close; this will send the SDATAC command to the ads
data_stream.into_inner();

Functionality

• Send commands:

ads1292.cmd(Command::START)?;

• Write to registers

ads1292.write_register(Register::CONFIG1, 0b001)?;

• Read from registers

let lead_off_status = ads1292.read_register(Register::LOFF_STAT)?;

• Read data

let data = ads1292.read_data()?;

• Read data continuously

// Opens stream, sends RDATAC command to ads
let data_stream = ads1292.into_data_stream()?;

let mut buf = [[Ads1292Data::default(); 2]; 2000];

for i in buf.iter_mut() {
    while !data_ready() {}
    *i = data_stream.next().unwrap().unwrap();
}
// Don't forget to close; this will send the SDATAC command to the ads
data_stream.into_inner();

TODO's

• Support ADS1292R
• Support ADS1291
• Non-blockingly wait after sending SPI commands
• Documentation
• Separate device-specific and universal code