Add a basic spi example

Author: david-sawatzke

examples/serial_spi_bridge.rs

@@ -0,0 +1,66 @@
+#![no_main]
+#![no_std]
+
+#[allow(unused)]
+use panic_halt;
+
+use stm32f0xx_hal as hal;
+
+use crate::hal::prelude::*;
+use crate::hal::serial::Serial;
+use crate::hal::spi::Spi;
+use crate::hal::spi::{Mode, Phase, Polarity};
+use crate::hal::stm32;
+
+use nb::block;
+
+use cortex_m_rt::entry;
+
+/// A basic serial to spi example
+///
+/// If you connect MOSI & MISO pins together, you'll see all characters
+/// that you typed in your serial terminal echoed back
+///
+/// If you connect MISO to GND, you'll see nothing coming back
+#[entry]
+fn main() -> ! {
+    const MODE: Mode = Mode {
+        polarity: Polarity::IdleHigh,
+        phase: Phase::CaptureOnSecondTransition,
+    };
+
+    if let Some(p) = stm32::Peripherals::take() {
+        let rcc = p.RCC.constrain();
+        let clocks = rcc.cfgr.freeze();
+        let gpioa = p.GPIOA.split();
+
+        // Configure pins for SPI
+        let sck = gpioa.pa5.into_alternate_af0();
+        let miso = gpioa.pa6.into_alternate_af0();
+        let mosi = gpioa.pa7.into_alternate_af0();
+
+        // Configure SPI with 1MHz rate
+        let mut spi = Spi::spi1(p.SPI1, (sck, miso, mosi), MODE, 1.mhz(), clocks);
+
+        let tx = gpioa.pa9.into_alternate_af1();
+        let rx = gpioa.pa10.into_alternate_af1();
+
+        let serial = Serial::usart1(p.USART1, (tx, rx), 115_200.bps(), clocks);
+
+        let (mut tx, mut rx) = serial.split();
+
+        loop {
+            let serial_received = block!(rx.read()).unwrap();
+
+            block!(spi.send(serial_received)).ok();
+
+            let spi_received = block!(spi.read()).unwrap();
+
+            block!(tx.write(spi_received)).ok();
+        }
+    }
+
+    loop {
+        continue;
+    }
+}