WIP: sample code and runner for mdk board.

1 files changed, 38 insertions, 2 deletions

diff --git a/ble/src/main.rs b/ble/src/main.rs
index e7a11a9..8b8c513 100644
--- a/ble/src/main.rs
+++ b/ble/src/main.rs
@@ -1,3 +1,39 @@
-fn main() {
-    println!("Hello, world!");
+//! BLE interface.
+#![no_std]
+#![no_main]
+
+use core::fmt::Write;
+use cortex_m_rt::entry;
+use nb::block;
+
+#[allow(unused_imports)]
+extern crate panic_semihosting;
+
+use nrf52840_mdk_bsp::{
+    hal::{
+        prelude::*,
+        timer::{self, Timer},
+    },
+    Board,
+};
+
+#[entry]
+fn main() -> ! {
+    let mut nrf52 = Board::take().unwrap();
+
+    let mut timer = Timer::new(nrf52.TIMER0);
+
+    write!(nrf52.cdc, "Bootstrap complete.").ok();
+    loop {
+        write!(nrf52.cdc, ".").ok();
+        delay(&mut timer, 1_000_000); // 1s
+    }
+}
+
+fn delay<T>(timer: &mut Timer<T>, cycles: u32)
+where
+    T: timer::Instance,
+{
+    timer.start(cycles);
+    let _ = block!(timer.wait());
 }