veml7700 0.3.2

Platform-agnostic Rust driver for the VEML7700 High Accuracy Ambient Light Sensor
Documentation 
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
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89

#![no_std]
#![no_main]

extern crate panic_halt;

use cortex_m::peripheral::Peripherals;

use cortex_m_rt::entry;

use stm32f4xx_hal::{
    i2c::{I2c, Mode},
    prelude::*,
    serial::{config::Config, Serial},
    pac as stm32,
};

use core::fmt::Write;

use veml7700::{PowerSavingMode, Veml7700};

#[entry]
fn main() -> ! {
    let cp = Peripherals::take().unwrap();

    let p = stm32::Peripherals::take().unwrap();

    let gpioa = p.GPIOA.split();
    let rcc = p.RCC.constrain();

    let clocks = rcc.cfgr.freeze();

    let mut led = gpioa.pa5.into_push_pull_output();
    led.set_low();

    let tx = gpioa.pa2.into_alternate();
    let rx = gpioa.pa3.into_alternate();

    let config = Config::default().baudrate(4_800.bps());

    let serial = Serial::new(p.USART2, (tx, rx), config, &clocks).unwrap();

    let (mut tx, _rx) = serial.split();

    let gpiob = p.GPIOB.split();
    let scl = gpiob
        .pb8
        .into_alternate()
        .internal_pull_up(true)
        .set_open_drain();

    let sda = gpiob
        .pb9
        .into_alternate()
        .internal_pull_up(true)
        .set_open_drain();

    let i2c = I2c::new(p.I2C1, (scl, sda), Mode::Standard { frequency: _fugit_RateExtU32::kHz(200) }, &clocks);

    writeln!(tx, "Ambient light sensor from Nucleo F401RE\r").ok();

    // Initialize the VEML7700 with the I2C
    let mut veml7700_device = Veml7700::new(i2c);

    let mut delay = cp.SYST.delay(&clocks);

    veml7700_device
        .enable_power_saving(PowerSavingMode::One)
        .unwrap();
    veml7700_device.enable().unwrap();

    loop {
        led.set_high();
        // current light state in lux and white light state
        let white = veml7700_device.read_white().unwrap();
        #[cfg(feature = "lux_as_f32")]
        {
            let lux = veml7700_device.read_lux().unwrap();
            writeln!(tx, "White: {}, Lux: {:2}\r", white, lux).ok();
        }
        #[cfg(not(feature = "lux_as_f32"))]
        {
            let raw = veml7700_device.read_raw().unwrap();
            writeln!(tx, "White: {}, Raw: {:#06x}", white, raw).ok();
        }

        led.set_low();
        delay.delay_ms(100);
    }
}