From dcadf16e1c345c92f913effa9236cc13001c49e7 Mon Sep 17 00:00:00 2001
From: Andy Killorin <andy@ank.dev>
Date: Thu, 10 Jul 2025 07:53:05 -0500
Subject: [PATCH] spin motors

currently the timer is not in independent mode, may need to drop to bits
---
 src/main.rs | 78 ++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 69 insertions(+), 9 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 7a6a7ba..a97a013 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,27 +1,87 @@
 #![no_std]
 #![no_main]
 
+use arduino_hal::hal::port::*;
+use arduino_hal::port::mode::*;
+use embedded_hal::digital::OutputPin;
 use panic_halt as _;
 
+fn shift_out(data_pin: &mut Pin<Output, PB0>, clock_pin: &mut Pin<Output, PD4>, data: &u8) {
+    for i in 0..8 {
+        let n = data & (1 << i);
+
+        if n == 0 {
+            data_pin.set_low();
+        } else {
+            data_pin.set_high();
+        }
+
+        clock_pin.set_high();
+        clock_pin.set_low();
+    }
+}
+
+fn update_shift_register(
+    data_pin: &mut Pin<Output, PB0>,
+    latch_pin: &mut Pin<Output, PB4>,
+    clock_pin: &mut Pin<Output, PD4>,
+    data: &u8,
+) {
+    latch_pin.set_low();
+
+    shift_out(data_pin, clock_pin, data);
+
+    latch_pin.set_high();
+}
+
 #[arduino_hal::entry]
 fn main() -> ! {
     let dp = arduino_hal::Peripherals::take().unwrap();
     let pins = arduino_hal::pins!(dp);
 
-    /*
-     * For examples (and inspiration), head to
-     *
-     *     https://github.com/Rahix/avr-hal/tree/main/examples
-     *
-     * NOTE: Not all examples were ported to all boards!  There is a good chance though, that code
-     * for a different board can be adapted for yours.  The Arduino Uno currently has the most
-     * examples available.
-     */
+    // shift register
+    let mut data_pin = pins.d8.into_output();
+    let mut clock_pin = pins.d4.into_output();
+    let mut enable_pin = pins.d7.into_output();
+    let mut latch_pin = pins.d12.into_output();
+
+    enable_pin.set_low(); // enable outputs
+
+    let _ = pins.d3.into_output(); // right
+    let _ = pins.d11.into_output(); // left
+
+    // TCCR2A |= _BV(COM2A1) | _BV(WGM20) | _BV(WGM21); // fast PWM, turn on oc2a
+    // TCCR2B = freq & 0x7;
+    // OCR2A = 0;
+    let tc2 = dp.TC2;
+    tc2.tccr2a.write(|w| { w
+            .wgm2().pwm_fast()
+            .com2a().match_set()
+            .com2b().match_set()
+    });
+    tc2.tccr2b.write(|w| w.cs2().prescale_8().foc2b().clear_bit().foc2a().clear_bit().wgm22().clear_bit());
+    tc2.ocr2a.write(|w| w.bits(2));
+    tc2.ocr2b.write(|w| w.bits(2));
 
     let mut led = pins.d13.into_output();
 
     loop {
+        let mut shift_register = 0;
+        const LEFT_FWD: u8 = 1 << 5; // 1a
+        const LEFT_REV: u8 = 1 << 4; // 1b
+        const RIGHT_FWD: u8 = 1 << 3; // 2b
+        const RIGHT_REV: u8 = 1 << 6; // 2a
+
         led.toggle();
+
+        shift_register |= LEFT_FWD | RIGHT_FWD;
+
+        // /255
+        tc2.ocr2a.write(|w| w.bits(1)); // right
+        tc2.ocr2b.write(|w| w.bits(1)); // left
+
+        update_shift_register(&mut data_pin, &mut latch_pin, &mut clock_pin, &shift_register);
+
         arduino_hal::delay_ms(1000);
     }
 }