1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
//! Example on how to read a 24C/24LC i2c eeprom with low power consumption.
//! The eeprom is read every 1 second, while ensuring lowest possible power while
//! sleeping between reads.
//!
//! Connect SDA to P0.03, SCL to P0.04
#![no_std]
#![no_main]
use core::mem;
use defmt::*;
use embassy_executor::Spawner;
use embassy_nrf::twim::{self, Twim};
use embassy_nrf::{bind_interrupts, peripherals};
use embassy_time::Timer;
use {defmt_rtt as _, panic_probe as _};
const ADDRESS: u8 = 0x50;
bind_interrupts!(struct Irqs {
TWISPI0 => twim::InterruptHandler<peripherals::TWISPI0>;
});
#[embassy_executor::main]
async fn main(_p: Spawner) {
let mut p = embassy_nrf::init(Default::default());
info!("Started!");
loop {
info!("Initializing TWI...");
let config = twim::Config::default();
let mut ram_buffer = [0u8; 16];
// Create the TWIM instance with borrowed singletons, so they're not consumed.
let mut twi = Twim::new(
p.TWISPI0.reborrow(),
Irqs,
p.P0_03.reborrow(),
p.P0_04.reborrow(),
config,
&mut ram_buffer,
);
info!("Reading...");
let mut buf = [0u8; 16];
unwrap!(twi.blocking_write_read(ADDRESS, &mut [0x00], &mut buf));
info!("Read: {=[u8]:x}", buf);
// Drop the TWIM instance. This disables the peripehral and deconfigures the pins.
// This clears the borrow on the singletons, so they can now be used again.
mem::drop(twi);
// Sleep for 1 second. The executor ensures the core sleeps with a WFE when it has nothing to do.
// During this sleep, the nRF chip should only use ~3uA
Timer::after_secs(1).await;
}
}
|
