From 4c6600e03694fb7df209235b2fe211acbfaa8017 Mon Sep 17 00:00:00 2001
From: Jan Niehusmann <jan@gondor.com>
Date: Sun, 30 Oct 2022 17:22:41 +0000
Subject: [PATCH] Extend pico_usb_serial example with some string formatting
---
boards/rp-pico/examples/pico_usb_serial.rs | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/boards/rp-pico/examples/pico_usb_serial.rs b/boards/rp-pico/examples/pico_usb_serial.rs
index 3210914..bc253aa 100644
--- a/boards/rp-pico/examples/pico_usb_serial.rs
+++ b/boards/rp-pico/examples/pico_usb_serial.rs
@@ -33,6 +33,10 @@ use usb_device::{class_prelude::*, prelude::*};
// USB Communications Class Device support
use usbd_serial::SerialPort;
+// Used to demonstrate writing formatted strings
+use core::fmt::Write;
+use heapless::String;
+
/// Entry point to our bare-metal application.
///
/// The `#[entry]` macro ensures the Cortex-M start-up code calls this function
@@ -101,6 +105,16 @@ fn main() -> ! {
if !said_hello && timer.get_counter().ticks() >= 2_000_000 {
said_hello = true;
let _ = serial.write(b"Hello, World!\r\n");
+
+ let time = timer.get_counter().ticks();
+ let mut text: String<64> = String::new();
+ writeln!(&mut text, "Current timer ticks: {}", time).unwrap();
+
+ // This only works reliably because the number of bytes written to
+ // the serial port is smaller than the buffers available to the USB
+ // peripheral. In general, the return value should be handled, so that
+ // bytes not transferred yet don't get lost.
+ let _ = serial.write(text.as_bytes());
}
// Check for new data