49 lines
1.3 KiB
Rust
49 lines
1.3 KiB
Rust
use crate::timer::sleep;
|
|
use stm32f4xx_hal::{
|
|
hal::{blocking::spi::Transfer, digital::v2::OutputPin},
|
|
spi,
|
|
time::MegaHertz,
|
|
};
|
|
|
|
/// SPI Mode 1
|
|
pub const SPI_MODE: spi::Mode = spi::Mode {
|
|
polarity: spi::Polarity::IdleLow,
|
|
phase: spi::Phase::CaptureOnSecondTransition,
|
|
};
|
|
/// 30 MHz
|
|
pub const SPI_CLOCK: MegaHertz = MegaHertz(30);
|
|
|
|
pub const MAX_VALUE: u32 = 0x3FFFF;
|
|
|
|
/// [AD5680](https://www.analog.com/media/en/technical-documentation/data-sheets/AD5680.pdf) DAC
|
|
pub struct Dac<SPI: Transfer<u8>, S: OutputPin> {
|
|
spi: SPI,
|
|
sync: S,
|
|
}
|
|
|
|
impl<SPI: Transfer<u8>, S: OutputPin> Dac<SPI, S> {
|
|
pub fn new(spi: SPI, mut sync: S) -> Self {
|
|
let _ = sync.set_low();
|
|
|
|
Dac { spi, sync }
|
|
}
|
|
|
|
fn write(&mut self, buf: &mut [u8]) -> Result<(), SPI::Error> {
|
|
// pulse sync to start a new transfer. leave sync idle low
|
|
// afterwards to save power as recommended per datasheet.
|
|
let _ = self.sync.set_high();
|
|
// must be high for >= 33 ns
|
|
sleep(1);
|
|
let _ = self.sync.set_low();
|
|
self.spi.transfer(buf)?;
|
|
Ok(())
|
|
}
|
|
|
|
pub fn set(&mut self, value: u32) -> Result<u32, SPI::Error> {
|
|
let value = value.min(MAX_VALUE);
|
|
let mut buf = [(value >> 14) as u8, (value >> 6) as u8, (value << 2) as u8];
|
|
self.write(&mut buf)?;
|
|
Ok(value)
|
|
}
|
|
}
|