freeshipping-controller/src/main.rs

//! Blinks an LED
//!
//! This assumes that a LED is connected to pc13 as is the case on the blue pill board.
//!
//! Note: Without additional hardware, PC13 should not be used to drive an LED, see page 5.1.2 of
//! the reference manaual for an explanation. This is not an issue on the blue pill.

#![deny(unsafe_code)]
#![deny(warnings)]
#![no_std]
#![no_main]

extern crate panic_halt;
extern crate cortex_m_semihosting;

use nb::block;

use stm32f1xx_hal::{
    prelude::*,
    pac,
    timer::Timer,
    serial::Serial,
};
use cortex_m_rt::entry;
//use cortex_m_semihosting::hprintln;
use stm32f1xx_hal::adc;

extern crate byteorder;
use byteorder::{ByteOrder, LittleEndian};

struct RangeConverter {
    // Input specifics
    left: u16,
    center: u16,
    right: u16,
    deadzone: u16,

    // Output range
    min: i16,
    max: i16,
}

impl RangeConverter {
    fn convert(&self, value: u16) -> i16 {
        if value <= self.left {
            return self.min
        }
        if value >= self.right {
            return self.max
        }

        let cd: u16 = if value > self.center {
            value - self.center
        } else {
            self.center - value
        };

        if cd <= self.deadzone {
            return 0;
        }

        // Value outside of deadzone.
        let cv: i16 = (cd - self.deadzone) as i16;
        if value > self.center {
            let md: i32 = ((self.right - self.center) - self.deadzone) as i32;
            let val: i32 = (self.max as i32) * (cv as i32) / md;
            return val as i16;
        } else {
            let md: i32 = ((self.center - self.left) - self.deadzone) as i32;
            let val: i32 = (self.min as i32) * (cv as i32) / md;
            return val as i16;
        }
    }
}

#[entry]
fn main() -> ! {
    // Get access to the core peripherals from the cortex-m crate
    let cp = cortex_m::Peripherals::take().unwrap();
    // Get access to the device specific peripherals from the peripheral access crate
    let dp = pac::Peripherals::take().unwrap();

    // Take ownership over the raw flash and rcc devices and convert them into the corresponding
    // HAL structs
    let mut flash = dp.FLASH.constrain();
    let mut rcc = dp.RCC.constrain();
    let mut afio = dp.AFIO.constrain(&mut rcc.apb2);

    // Freeze the configuration of all the clocks in the system and store the frozen frequencies in
    // `clocks`
    let clocks = rcc.cfgr.adcclk(2.mhz()).freeze(&mut flash.acr);
    //hprintln!("adc freq: {}", clocks.adcclk().0).unwrap();

    // Acquire the GPIOC peripheral
    let mut gpioa = dp.GPIOA.split(&mut rcc.apb2);
    let mut gpiob = dp.GPIOB.split(&mut rcc.apb2);
    let mut gpioc = dp.GPIOC.split(&mut rcc.apb2);

    // Configure gpio C pin 13 as a push-pull output. The `crh` register is passed to the function
    // in order to configure the port. For pins 0-7, crl should be passed instead.
    let mut led = gpioc.pc13.into_push_pull_output(&mut gpioc.crh);
    // Configure the syst timer to trigger an update every second
    let mut timer = Timer::syst(cp.SYST, 30.hz(), clocks);

    let mut adc1 = adc::Adc::adc1(dp.ADC1, &mut rcc.apb2);

    let mut ch0 = gpiob.pb0.into_analog(&mut gpiob.crl);
    let mut ch1 = gpiob.pb1.into_analog(&mut gpiob.crl);
    let mut ch2 = gpioa.pa0.into_analog(&mut gpioa.crl);

    let fire = gpioc.pc14.into_pull_up_input(&mut gpioc.crh);
    let tx = gpioa.pa2.into_alternate_push_pull(&mut gpioa.crl);
    let rx = gpioa.pa3;
    let serial = Serial::usart2(
        dp.USART2,
        (tx, rx),
        &mut afio.mapr,
        19_200.bps(),
        clocks,
        &mut rcc.apb1,
    );
    let (mut tx, mut _rx) = serial.split();

    let rcx = RangeConverter{
        left: 2064,
        center: 3026,
        right: 4096,
        deadzone: 300,

        min: -1000,
        max: 1000,
    };
    let rcy = RangeConverter{
        left: 2250,
        center: 3000,
        right: 4096,
        deadzone: 100,

        min: -1000,
        max: 1000,
    };

    // Wait for the timer to trigger an update and change the state of the LED
    loop {
        block!(timer.wait()).unwrap();
        led.set_high();
        block!(timer.wait()).unwrap();
        led.set_low();

        let data0: u16 = adc1.read(&mut ch0).unwrap();
        let data1: u16 = adc1.read(&mut ch1).unwrap();
        let _data2: u16 = adc1.read(&mut ch2).unwrap();

        let x: i16 = -rcx.convert(data0);
        let y: i16 = rcy.convert(data1);

        let mut bufx = [0, 0];
        let mut bufy = [0, 0];
        if fire.is_low() {
            LittleEndian::write_i16(&mut bufx, x);
            LittleEndian::write_i16(&mut bufy, y);
        } else {
            LittleEndian::write_i16(&mut bufx, 0);
            LittleEndian::write_i16(&mut bufy, 0);
        };
        block!(tx.write(bufx[0])).ok();
        block!(tx.write(bufx[1])).ok();
        block!(tx.write(bufy[0])).ok();
        block!(tx.write(bufy[1])).ok();
    }
}