tests/rp: add timer test.

tests/rp/src/bin/timer.rs

@@ -0,0 +1,25 @@
+#![no_std]
+#![no_main]
+teleprobe_meta::target!(b"rpi-pico");
+
+use defmt::{assert, *};
+use embassy_executor::Spawner;
+use embassy_time::{Instant, Timer};
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let _p = embassy_rp::init(Default::default());
+    info!("Hello World!");
+
+    let start = Instant::now();
+    Timer::after_millis(100).await;
+    let end = Instant::now();
+    let ms = (end - start).as_millis();
+    info!("slept for {} ms", ms);
+    assert!(ms >= 99);
+    assert!(ms < 110);
+
+    info!("Test OK");
+    cortex_m::asm::bkpt();
+}