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Code Issues Releases Activity

Display compass values on LEDs.

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This commit is contained in:
Andrew Walbran 2023-03-09 14:39:31 +00:00
parent 82f4dab523
commit 44a4b4b234
1 changed files with 29 additions and 0 deletions
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29
src/exercises/bare-metal/compass/src/main.rs
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@ -21,16 +21,21 @@ extern crate panic_halt as _;
use core::fmt::Write;
use cortex_m_rt::entry;
// ANCHOR_END: top
use core::cmp::{max, min};
use lsm303agr::{Lsm303agr, MagOutputDataRate};
use microbit::{
display::blocking::Display,
hal::{
twim::Twim,
uarte::{Baudrate, Parity, Uarte},
Timer,
},
pac::twim0::frequency::FREQUENCY_A,
Board,
};
const COMPASS_SCALE: i32 = 30000;
// ANCHOR: main
#[entry]
fn main() -> ! {
@ -53,6 +58,10 @@ fn main() -> ! {
imu.set_mag_odr(MagOutputDataRate::Hz50).unwrap();
let mut imu = imu.into_mag_continuous().ok().unwrap();
// Set up display and timer.
let mut timer = Timer::new(board.TIMER0);
let mut display = Display::new(board.display_pins);
// ANCHOR: loop
writeln!(serial, "Ready.").unwrap();
@ -67,5 +76,25 @@ fn main() -> ! {
compass_reading.x, compass_reading.y, compass_reading.z
)
.unwrap();
let mut image = [[0; 5]; 5];
let x = scale(-compass_reading.x, -COMPASS_SCALE, COMPASS_SCALE, 0, 4) as usize;
let y = scale(compass_reading.y, -COMPASS_SCALE, COMPASS_SCALE, 0, 4) as usize;
image[y][x] = 255;
display.show(&mut timer, image, 100);
}
}
fn scale(value: i32, min_in: i32, max_in: i32, min_out: i32, max_out: i32) -> i32 {
let range_in = max_in - min_in;
let range_out = max_out - min_out;
cap(
min_out + range_out * (value - min_in) / range_in,
min_out,
max_out,
)
}
fn cap(value: i32, min_value: i32, max_value: i32) -> i32 {
max(min_value, min(value, max_value))
}