use defmt::assert; add defmt::panic_handler

src/lib.rs

@@ -3,10 +3,18 @@
 use core::sync::atomic::{AtomicUsize, Ordering};
 
 use defmt_rtt as _; // global logger
-use panic_probe as _;
 // TODO(5) adjust HAL import
 // use some_hal as _; // memory layout
 
+use panic_probe as _;
+
+// same panicking *behavior* as `panic-probe` but doesn't print a panic message
+// this prevents the panic message being printed *twice* when `defmt::panic` is invoked
+#[defmt::panic_handler]
+fn panic() -> ! {
+    cortex_m::asm::udf()
+}
+
 #[defmt::timestamp]
 fn timestamp() -> u64 {
     static COUNT: AtomicUsize = AtomicUsize::new(0);