feat: added display code, basic packet handling

added a super basic packet handling mechanism with a tiny buffer,
allowing for easier expansion later on. Added display code, waiting for
actual display to test, improved the cpu load script

Cargo.toml

@@ -14,7 +14,8 @@ panic-halt = "0.2.0"
 ufmt = "0.1.0"
 nb = "1"
 embedded-hal = "0.2.3"
-embedded-msgpack = "0.2"
+sh1106 = "0.4"
+embedded-graphics = "0.7"
 
 [dependencies.arduino-hal]
 git = "https://github.com/rahix/avr-hal"

script/cpu-usage.py

@@ -1,22 +1,38 @@
 #!/usr/bin/env python
-from time import sleep
+import sys
 import struct
-import serial
+from time import sleep
 
+import serial
 import psutil
 
-def avg_usage_to_serial(dev:str):
-	port = serial.Serial(dev, baudrate=57600)
+def cpu_load_serial_driver(device:str, retry_interval:float=5.0):
+	while True:
+		try:
+			port = serial.Serial(device, baudrate=57600)
+			avg_usage_to_serial(port)
+		except serial.SerialException as e:
+			print(f"[!] Could not connect to device: {str(e)}", file=sys.stderr)
+		sleep(retry_interval)
+
+def avg_usage_to_serial(port:serial.Serial):
+	port.write(struct.pack("BB", 0, 0))
+	port.flush()
 	while True:
 		# Map float [0:100] to int [0:255], square it to put more values in the lower end, where led is more sensible
-		load = [ int(((x/100) **2) * 255) for x in psutil.cpu_percent(0.1, percpu=True) ] # mypy whines but percpu returns a list
-		port.write(struct.pack("BBBB", *load))
-		port.flush()
+		load = [ int(((x/100) **2) * 255) for x in psutil.cpu_percent(0.05, percpu=True) ] # mypy whines but percpu returns a list
+		try:
+			port.write(struct.pack("BBBBBB", 1, 4, *load))
+			port.flush()
+		except serial.SerialException as e:
+			print(f"[!] Failed writing payload to device: {str(e)}", file=sys.stderr)
+			break
+
 
 if __name__ == "__main__":
-	import sys
 	if len(sys.argv) < 2:
 		print("[!] No device specified")
-	else:
-		avg_usage_to_serial(sys.argv[1])
+		exit(-1)
+	
+	cpu_load_serial_driver(sys.argv[1])
 

src/main.rs

@@ -1,91 +1,96 @@
 #![no_std]
 #![no_main]
 
+use packet::PacketId;
 use panic_halt as _;
 
 use embedded_hal::serial::Read;
 
-use arduino_hal::{simple_pwm::*, port::{Pin, mode::{PwmOutput, PullUp, Input}}, hal::port::{PD3, PB1, PB2, PB3, PD2}};
+use arduino_hal::simple_pwm::{IntoPwmPin, Prescaler, Timer1Pwm, Timer2Pwm};
+use sh1106::{prelude::GraphicsMode, Builder};
 
-// TODO can I make it a generic "Pin" and use a slice?
-struct FourLedDisplay {
-	led1: Pin<PwmOutput<Timer2Pwm>, PD3>,
-	led2: Pin<PwmOutput<Timer1Pwm>, PB1>,
-	led3: Pin<PwmOutput<Timer1Pwm>, PB2>,
-	led4: Pin<PwmOutput<Timer2Pwm>, PB3>,
-	button: Pin<Input<PullUp>, PD2>,
-	counter: u8,
-}
+mod packet;
+mod utils;
 
-impl FourLedDisplay {
-	fn new(
-		led1: Pin<PwmOutput<Timer2Pwm>, PD3>,
-		led2: Pin<PwmOutput<Timer1Pwm>, PB1>,
-		led3: Pin<PwmOutput<Timer1Pwm>, PB2>,
-		led4: Pin<PwmOutput<Timer2Pwm>, PB3>,
-		button: Pin<Input<PullUp>, PD2>,
-	) -> Self {
-		FourLedDisplay{
-			led1, led2, led3, led4, button,
-			counter: 0,
-		}
-	}
-
-	fn update(&mut self, value: u8) {
-		match self.counter {
-			0 => self.led1.set_duty(value),
-			1 => self.led2.set_duty(value),
-			2 => self.led3.set_duty(value),
-			3 => self.led4.set_duty(value),
-			_ => {},
-		}
-		self.counter = (self.counter + 1) % 4;
-	}
-
-	fn init(mut self) -> Self {
-		self.led1.enable();
-		self.led2.enable();
-		self.led3.enable();
-		self.led4.enable();
-		self
-	}
-
-	fn should_reset(&self) -> bool { self.button.is_low() }
-
-	fn reset(&mut self) {
-		self.counter = 0;
-		self.led1.set_duty(0);
-		self.led2.set_duty(0);
-		self.led3.set_duty(0);
-		self.led4.set_duty(0);
-	}
-}
+use crate::packet::PacketBuilder;
+use crate::utils::FourLedDisplay;
 
 #[arduino_hal::entry]
 fn main() -> ! {
 	// init board peripherals
 	let dp = arduino_hal::Peripherals::take().unwrap();
-	let timer1 = Timer1Pwm::new(dp.TC1, Prescaler::Prescale8);
-	let timer2 = Timer2Pwm::new(dp.TC2, Prescaler::Prescale8);
+	let timer1 = Timer1Pwm::new(dp.TC1, Prescaler::Direct);
+	let timer2 = Timer2Pwm::new(dp.TC2, Prescaler::Direct);
 	let pins = arduino_hal::pins!(dp);
-	let led1 = pins.d3.into_output().into_pwm(&timer2);
-	let led2 = pins.d9.into_output().into_pwm(&timer1);
-	let led3 = pins.d10.into_output().into_pwm(&timer1);
-	let led4 = pins.d11.into_output().into_pwm(&timer2);
+	let mut led_load = pins.d6.into_output();
 	let button = pins.d2.into_pull_up_input();
+	let mut cpu_leds = FourLedDisplay::new(
+		pins.d3.into_output().into_pwm(&timer2),
+		pins.d9.into_output().into_pwm(&timer1),
+		pins.d10.into_output().into_pwm(&timer1),
+		pins.d11.into_output().into_pwm(&timer2),
+	);
+	let i2c = arduino_hal::i2c::I2c::new(
+		dp.TWI, pins.a4.into_pull_up_input(), pins.a5.into_pull_up_input(), 100000
+	);
 	let mut serial = arduino_hal::default_serial!(dp, pins, 57600);
 
-	// prepare display struct
-	let mut display = FourLedDisplay::new(led1, led2, led3, led4, button).init();
+	led_load.set_high();
+	
+	// prepare display
+	let mut display: GraphicsMode<_> = Builder::new().with_size(sh1106::prelude::DisplaySize::Display128x64).connect_i2c(i2c).into();
+	cpu_leds.set(1, 255);
 
+	display.init().unwrap();
+	cpu_leds.set(2, 255);
+
+	let mut flip : u8 = 0;
+	for x in 0..128 {
+		for y in 0..64 {
+			cpu_leds.set(3, if flip == 0 { 0 } else { 255 });
+			display.set_pixel(x, y, flip);
+			flip = !flip;
+		}
+	}
+	cpu_leds.set(3, 255);
+
+	display.flush().unwrap();
+	cpu_leds.set(4, 255);
+
+	led_load.set_low();
+
+	let mut pkt_builder = PacketBuilder::new();
+
+	arduino_hal::delay_ms(25);
+	cpu_leds.set_all(0);
 	loop { // main loop
-		if display.should_reset() {
-			display.reset();
-		} else {
-			match serial.read() {
-				Ok(value) => display.update(value),
-				Err(_) => {},
-			}
+		if button.is_low() { // If reset button is pressed, don't process serial bus
+			cpu_leds.set_all(0);
+			led_load.set_high();
+			continue;
+		}
+
+		match serial.read() { // if there's a byte available
+			Ok(value) => {
+				led_load.set_high();
+				if let Some(pkt) = pkt_builder.update(value) { // update packet builder
+					match pkt.id { // if a packet is ready, match against its id
+						PacketId::Reset => {
+							cpu_leds.set_all(0);
+						},
+						PacketId::SetLedsPacket => {
+							if let Some(payload) = pkt.payload && payload.len() == 4 {
+								cpu_leds.set_many(payload[0], payload[1], payload[2], payload[3]);
+							}
+						},
+						_ => {}, // TODO log it?
+					}
+				}
+			},
+			Err(_) => {
+				led_load.set_low();
+			},
 		}
 	}
 }
+

src/packet.rs

@@ -0,0 +1,92 @@
+const PACKET_BUFFER : usize = 32;
+
+#[derive(Copy, Clone)]
+pub enum PacketId {
+	Invalid = 0xFF,
+	Reset = 0x00,
+	SetLedsPacket = 0x01,
+}
+
+impl From<u8> for PacketId {
+	fn from(x: u8) -> Self {
+		match x {
+			0 => PacketId::Reset,
+			1 => PacketId::SetLedsPacket,
+			_ => PacketId::Invalid,
+		}
+	}
+}
+
+pub struct Packet<'a> {
+	pub id: PacketId,
+	pub payload: Option<&'a[u8]>,
+}
+
+enum PacketBuilderStep {
+	ID,
+	SIZE,
+	PAYLOAD,
+}
+
+pub struct PacketBuilder {
+	step: PacketBuilderStep,
+	id: PacketId,
+	size: u8,
+	index: usize,
+	buffer: [u8; PACKET_BUFFER],
+}
+
+impl PacketBuilder {
+	pub fn new() -> Self {
+		PacketBuilder {
+			step: PacketBuilderStep::ID,
+			id: PacketId::Invalid,
+			size: 0,
+			index: 0,
+			buffer: [0;PACKET_BUFFER],
+		}
+	}
+
+	pub fn update(&mut self, byte:u8) -> Option<Packet> {
+		let mut ret = None;
+		match self.step {
+			PacketBuilderStep::ID => {
+				let id = PacketId::from(byte);
+				match id {
+					PacketId::SetLedsPacket | PacketId::Reset => {
+						self.id = id;
+						self.step = PacketBuilderStep::SIZE;
+					},
+					_ => {
+						// TODO log it somehow?
+					},
+				}
+			},
+			PacketBuilderStep::SIZE => {
+				if byte as usize > PACKET_BUFFER {
+					self.step = PacketBuilderStep::ID;
+					// TODO log it somehow?
+				} else if byte == 0 {
+					// packet without payload
+					ret = Some(Packet{id: self.id, payload: None}); // jank zero size slice
+					self.step = PacketBuilderStep::ID;
+				} else {
+					self.size = byte;
+					self.index = 0;
+					self.step = PacketBuilderStep::PAYLOAD;
+				}
+			},
+			PacketBuilderStep::PAYLOAD => {
+				self.buffer[self.index] = byte;
+				self.index += 1;
+				if self.index >= self.size as usize {
+					ret = Some(Packet{id: self.id, payload: Some(&self.buffer[0..self.size as usize])});
+					self.step = PacketBuilderStep::ID;
+				}
+			},
+		}
+		ret
+	}
+}
+
+

src/utils.rs

@@ -0,0 +1,53 @@
+use arduino_hal::{simple_pwm::*, port::{Pin, mode::PwmOutput}, hal::port::{PD3, PB1, PB2, PB3}};
+
+// TODO can I make it a generic "Pin" and use a slice?
+pub struct FourLedDisplay {
+	led1: Pin<PwmOutput<Timer2Pwm>, PD3>,
+	led2: Pin<PwmOutput<Timer1Pwm>, PB1>,
+	led3: Pin<PwmOutput<Timer1Pwm>, PB2>,
+	led4: Pin<PwmOutput<Timer2Pwm>, PB3>,
+}
+
+impl FourLedDisplay {
+	pub fn new(
+		mut led1: Pin<PwmOutput<Timer2Pwm>, PD3>,
+		mut led2: Pin<PwmOutput<Timer1Pwm>, PB1>,
+		mut led3: Pin<PwmOutput<Timer1Pwm>, PB2>,
+		mut led4: Pin<PwmOutput<Timer2Pwm>, PB3>,
+	) -> Self {
+		led1.enable();
+		led2.enable();
+		led3.enable();
+		led4.enable();
+		FourLedDisplay{
+			led1, led2, led3, led4,
+		}
+	}
+
+	pub fn set(&mut self, index:u8, value:u8) -> &mut Self {
+		match index {
+			1 => self.led1.set_duty(value),
+			2 => self.led2.set_duty(value),
+			3 => self.led3.set_duty(value),
+			4 => self.led4.set_duty(value),
+			_ => {},
+		}
+		self
+	}
+
+	pub fn set_all(&mut self, value:u8) -> &mut Self {
+		self.led1.set_duty(value);
+		self.led2.set_duty(value);
+		self.led3.set_duty(value);
+		self.led4.set_duty(value);
+		self
+	}
+
+	pub fn set_many(&mut self, first:u8, second:u8, third:u8, fourth:u8) -> &mut Self {
+		self.led1.set_duty(first);
+		self.led2.set_duty(second);
+		self.led3.set_duty(third);
+		self.led4.set_duty(fourth);
+		self
+	}
+}