zaubentrucker/co2_sensing
1
0
Fork 0
Code Issues Pull requests Actions Packages Projects Releases Wiki Activity

Move sensor code to own module

Browse source
This commit is contained in:
Frederik Menke 2024-07-21 13:22:30 +02:00
parent 56ac102a9b
commit 02c8102e35
2 changed files with 95 additions and 76 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

71
src/co2_sensor.rs Normal file
View file

@ -0,0 +1,71 @@
use embassy_rp::{
i2c::{Async, I2c},
peripherals::I2C1,
};
/// I2C Address of the co2 sensor
const CCS811_I2C_ADDRESS: u16 = 0x5A;
/// Application I2C Register addresses of the co2 sensor
const CCS811_REGISTER_STATUS: u8 = 0x00;
const CCS811_REGISTER_MEAS_MODE: u8 = 0x01;
const CCS811_REGISTER_ALG_RESULT_DATA: u8 = 0x02;
/// Bootloader I2C Register addresses of the co2 sensor
const CCS811_REGISTER_BOOTLOADER_APP_START: u8 = 0xF4;
/// Read `buf.len()` bytes from register `register_address` over I2C
pub async fn read_register(
i2c: &mut I2c<'_, I2C1, Async>,
register_address: u8,
buf: &mut [u8],
) -> Result<(), embassy_rp::i2c::Error> {
i2c.write_async(CCS811_I2C_ADDRESS, [register_address])
.await?;
i2c.read_async(CCS811_I2C_ADDRESS, buf).await
}
/// Write all `bytes` in to register `register_address` over I2C
pub async fn write_register(
i2c: &mut I2c<'_, I2C1, Async>,
register_address: u8,
bytes: impl IntoIterator<Item = u8>,
) -> Result<(), embassy_rp::i2c::Error> {
let write_buffer = core::iter::once(register_address).chain(bytes);
i2c.write_async(CCS811_I2C_ADDRESS, write_buffer).await
}
/// Start the application on the sensor. The device can run custom applications.
/// However, there is no documentation about how these applications can be put together.
/// Therefore, we're just using whatever is already programmed on the chip.
pub async fn start_app(i2c: &mut I2c<'_, I2C1, Async>) -> Result<(), embassy_rp::i2c::Error> {
i2c.write_async(CCS811_I2C_ADDRESS, [CCS811_REGISTER_BOOTLOADER_APP_START])
.await
}
/// Read the status byte from the device
pub async fn get_status(i2c: &mut I2c<'_, I2C1, Async>) -> Result<u8, embassy_rp::i2c::Error> {
let mut res = [0];
read_register(i2c, CCS811_REGISTER_STATUS, &mut res).await?;
Ok(res[0])
}
/// Read the eCO2 value from the `ALG_RESULT_DATA` register on the sensor
pub async fn get_measurement(
i2c: &mut I2c<'_, I2C1, Async>,
) -> Result<u16, embassy_rp::i2c::Error> {
let mut res = [0; 2];
read_register(i2c, CCS811_REGISTER_ALG_RESULT_DATA, &mut res).await?;
Ok(u16::from_be_bytes(res))
}
/// Set the measurement mode register.
/// The measurement mode register is a bit field that also controls the
/// interrupt behavior.
/// By setting this register to `16`, you can select 1Hz constant power mode
/// without interrupts.
pub async fn set_measurement_mode(
i2c: &mut I2c<'_, I2C1, Async>,
mode: u8,
) -> Result<(), embassy_rp::i2c::Error> {
write_register(i2c, CCS811_REGISTER_MEAS_MODE, [mode]).await
}

100
src/main.rs
View file

@ -6,44 +6,33 @@
#![no_std]
#![no_main]
use core::future::ready;
mod co2_sensor;
use byteorder::ByteOrder;
use defmt::*;
use embassy_embedded_hal::SetConfig;
use embassy_executor::Spawner;
use embassy_rp::bind_interrupts;
use embassy_rp::peripherals::{PIN_10, PIN_11, PIN_12, PIN_16, SPI1};
use embassy_rp::spi::Spi;
use embassy_rp::{bind_interrupts, interrupt};
use embassy_rp::{gpio, spi};
use embedded_hal_bus::spi::ExclusiveDevice;
use embedded_sdmmc::sdcard::{DummyCsPin, SdCard};
use embedded_sdmmc::{Block, BlockDevice, BlockIdx, VolumeIdx};
use futures::{FutureExt, TryFutureExt};
use gpio::{Level, Output};
use usbd_hid::descriptor::MouseReport;
use {defmt_rtt as _, panic_probe as _};
use embassy_rp::i2c::{self, Config};
use embassy_time::{Duration, Timer};
use co2_sensor::{get_measurement, get_status, set_measurement_mode, start_app};
bind_interrupts!(struct Irqs {
I2C1_IRQ => i2c::InterruptHandler<embassy_rp::peripherals::I2C1>;
});
struct DummyTimesource();
/// I2C Address of the co2 sensor
const CCS811_I2C_ADDRESS: u16 = 0x5A;
/// Application I2C Register addresses of the co2 sensor
const CCS811_REGISTER_STATUS: u8 = 0x00;
const CCS811_REGISTER_MEAS_MODE: u8 = 0x01;
const CCS811_REGISTER_ALG_RESULT_DATA: u8 = 0x02;
/// Bootloader I2C Register addresses of the co2 sensor
const CCS811_REGISTER_BOOTLOADER_APP_START: u8 = 0xF4;
const CCS811_REGISTER_BOOTLOADER_STATUS: u8 = CCS811_REGISTER_STATUS;
impl embedded_sdmmc::TimeSource for DummyTimesource {
fn get_timestamp(&self) -> embedded_sdmmc::Timestamp {
embedded_sdmmc::Timestamp {
@ -78,73 +67,32 @@ async fn main(spawner: Spawner) {
// Wait for sensor to boot
Timer::after(Duration::from_secs(1)).await;
debug!("Writing to I2C");
let mut status = [42u8];
i2c.write_async(CCS811_I2C_ADDRESS, [CCS811_REGISTER_STATUS])
.await
.unwrap();
debug!("Reading from I2C");
i2c.read_async(CCS811_I2C_ADDRESS, &mut status)
.await
.unwrap();
let status = status[0];
let status = get_status(&mut i2c).await.unwrap();
info!("Reported status: {}", status);
match status {
16u8 => {}
144u8 => {
warn!("Sensor already in APP mode! Configuration may come from previous boot.");
}
unexpected => {
warn!(
"Sensor reported unexpected state after boot: {}",
unexpected
);
info!("CO2 sesor reported status on boot: {}", status);
// Byte 7 is FW_MODE which indicates if the app is already running.
if status & 128u8 == 0 {
info!("App is not running yet. Booting sensor...");
// App is not running
start_app(&mut i2c).await.unwrap();
// After APP_START, we have to wait at least 1 ms (according to datasheet)
Timer::after(Duration::from_millis(2)).await;
if get_status(&mut i2c).await.unwrap() & 128u8 == 0 {
error!("App still not running after boot! Terminating...");
return;
}
} else {
info!("App is already running. Skipping boot...");
}
// APP_START does not require to write data
i2c.write_async(CCS811_I2C_ADDRESS, [CCS811_REGISTER_BOOTLOADER_APP_START])
.await
.unwrap();
// After APP_START, we have to wait 1 ms (according to datasheet)
Timer::after(Duration::from_millis(1000)).await;
// Mode 1 is 1 measurement per second
i2c.write_async(CCS811_I2C_ADDRESS, [CCS811_REGISTER_MEAS_MODE, 16])
.await
.unwrap();
// 16 is measurement mode 1 => 1 measurement per second
set_measurement_mode(&mut i2c, 16).await.unwrap();
loop {
let mut status = [42u8];
i2c.write_async(CCS811_I2C_ADDRESS, [CCS811_REGISTER_STATUS])
.await;
// .unwrap();
i2c.read_async(CCS811_I2C_ADDRESS, &mut status).await;
// .unwrap();
let status = status[0];
let mut measured_value_buffer = [42u8; 2];
let address_written = i2c
.write_async(CCS811_I2C_ADDRESS, [CCS811_REGISTER_ALG_RESULT_DATA])
.await
.ok();
let data_written = if let Some(()) = address_written {
i2c.read_async(CCS811_I2C_ADDRESS, &mut measured_value_buffer)
.await
.ok()
} else {
None
};
let measured_value = if let Some(()) = data_written {
Some(u16::from_be_bytes(measured_value_buffer))
} else {
None
};
let status = get_status(&mut i2c).await.unwrap();
let measured_value = get_measurement(&mut i2c).await.unwrap();
info!(
"Reported status: {}\tMeasured value: {}",
status, measured_value