#![no_std]
#![no_main]
use esp32c3_hal::{
clock::ClockControl,
dma::DmaPriority,
gdma::Gdma,
i2s::{DataFormat, I2s, I2s0New, I2sWriteDma, MclkPin, PinsBclkWsDout, Standard},
peripherals::Peripherals,
prelude::*,
timer::TimerGroup,
Rtc,
IO,
};
use esp_backtrace as _;
const SINE: [i16; 64] = [
0, 3211, 6392, 9511, 12539, 15446, 18204, 20787, 23169, 25329, 27244, 28897, 30272, 31356,
32137, 32609, 32767, 32609, 32137, 31356, 30272, 28897, 27244, 25329, 23169, 20787, 18204,
15446, 12539, 9511, 6392, 3211, 0, -3211, -6392, -9511, -12539, -15446, -18204, -20787, -23169,
-25329, -27244, -28897, -30272, -31356, -32137, -32609, -32767, -32609, -32137, -31356, -30272,
-28897, -27244, -25329, -23169, -20787, -18204, -15446, -12539, -9511, -6392, -3211,
];
#[entry]
fn main() -> ! {
let peripherals = Peripherals::take();
let mut system = peripherals.SYSTEM.split();
let clocks = ClockControl::boot_defaults(system.clock_control).freeze();
let mut rtc = Rtc::new(peripherals.RTC_CNTL);
let timer_group0 = TimerGroup::new(peripherals.TIMG0, &clocks);
let mut wdt0 = timer_group0.wdt;
let timer_group1 = TimerGroup::new(peripherals.TIMG1, &clocks);
let mut wdt1 = timer_group1.wdt;
rtc.swd.disable();
rtc.rwdt.disable();
wdt0.disable();
wdt1.disable();
let io = IO::new(peripherals.GPIO, peripherals.IO_MUX);
let dma = Gdma::new(peripherals.DMA, &mut system.peripheral_clock_control);
let dma_channel = dma.channel0;
let mut tx_descriptors = [0u32; 20 * 3];
let mut rx_descriptors = [0u32; 8 * 3];
let i2s = I2s::new(
peripherals.I2S,
MclkPin::new(io.pins.gpio4),
Standard::Philips,
DataFormat::Data16Channel16,
44100u32.Hz(),
dma_channel.configure(
false,
&mut tx_descriptors,
&mut rx_descriptors,
DmaPriority::Priority0,
),
&mut system.peripheral_clock_control,
&clocks,
);
let i2s_tx = i2s.i2s_tx.with_pins(PinsBclkWsDout::new(
io.pins.gpio1,
io.pins.gpio2,
io.pins.gpio3,
));
let data =
unsafe { core::slice::from_raw_parts(&SINE as *const _ as *const u8, SINE.len() * 2) };
let buffer = dma_buffer();
let mut idx = 0;
for i in 0..usize::min(data.len(), buffer.len()) {
buffer[i] = data[idx];
idx += 1;
if idx >= data.len() {
idx = 0;
}
}
let mut filler = [0u8; 10000];
let mut transfer = i2s_tx.write_dma_circular(buffer).unwrap();
loop {
let avail = transfer.available();
if avail > 0 {
let avail = usize::min(10000, avail);
for bidx in 0..avail {
filler[bidx] = data[idx];
idx += 1;
if idx >= data.len() {
idx = 0;
}
}
transfer.push(&filler[0..avail]).unwrap();
}
}
}
fn dma_buffer() -> &'static mut [u8; 32000] {
static mut BUFFER: [u8; 32000] = [0u8; 32000];
unsafe { &mut BUFFER }
}