From 02a4856b9893e8dd936ec32606db2064e2294b12 Mon Sep 17 00:00:00 2001
From: JP Stringham <jp@bloomdigital.to>
Date: Sat, 24 Jan 2026 09:45:41 -0500
Subject: [PATCH] Various improvements, set to walk through charge duty for
 testing

---
 src/main.rs | 83 +++++++++++++++++++++++++++++++++++------------------
 1 file changed, 55 insertions(+), 28 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 7194ab3..57377eb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -36,7 +36,7 @@ pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER_GENERIC_03H;
 const XTAL_FREQ_HZ: u32 = 12_000_000u32;
 
 // below this we won't be able to turn on the transistor (0.6v)
-const MIN_DUTY: u16 = 12000;
+const MIN_DUTY: u16 = 6000;
 
 #[rp2040_hal::entry]
 fn main() -> ! {
@@ -75,19 +75,23 @@ fn main() -> ! {
     let mut adc_pin = hal::adc::AdcPin::new(pins.gpio26.into_floating_input()).unwrap();
     let mut adc_fifo = adc
         .build_fifo()
-        .clock_divider(0xFFFF, 0xFF)
         .set_channel(&mut adc_pin)
-        .start();
+        .clock_divider(47999, 0)
+        .start_paused();
 
     let mut pwm_slices = hal::pwm::Slices::new(pac.PWM, &mut pac.RESETS);
 
     let pwm = &mut pwm_slices.pwm2;
-    pwm.set_div_int(125);
+    // info!("PWM Top: {}", pwm.get_top());
     pwm.set_ph_correct();
     pwm.enable();
 
     let pwm_channel = &mut pwm.channel_a;
     pwm_channel.output_to(pins.gpio20);
+    pwm_channel.set_duty_cycle(MIN_DUTY);
+
+    // calibrate
+    delay.delay_ms(2000);
 
     // let mut led_pin = pins.gpio25.into_push_pull_output();
 
@@ -95,36 +99,59 @@ fn main() -> ! {
 
     let mut power = 0;
 
-    let mut tick = 0u16;
+    let mut tick = 19u8;
+
+    let mut peak_v = 0u32;
 
     loop {
         pwm_channel.set_duty_cycle(duty);
-        duty = duty.saturating_add(2000);
 
-        delay.delay_ms(10);
-        if adc_fifo.len() > 7 {
-            let mut samps = [0u16; 8];
+        delay.delay_ms(500);
+        adc_fifo.clear();
+        adc_fifo.resume();
 
-            for i in 0..8 {
-                samps[i] = adc_fifo.read();
-            }
-
-            let avg = avg_fifo(&samps, false);
-            let voltage = (avg * 3300) / 4095;
-
-            let new_power = (voltage * (duty - MIN_DUTY) as u32) / 0xFFF;
-
-            if tick % 10 == 0 {
-                info!("{} duty, {}mV, {} power", duty, voltage, new_power);
-            }
-            tick = tick.wrapping_add(1);
-
-            if new_power < power {
-                duty = MIN_DUTY.max(duty - 3000);
-            }
-
-            power = new_power;
+        while adc_fifo.len() < 7 {
+            delay.delay_us(1);
         }
+
+        adc_fifo.pause();
+
+        let mut samps = [0u16; 8];
+
+        for i in 0..8 {
+            samps[i] = adc_fifo.read();
+        }
+
+        let avg = avg_fifo(&samps, false);
+        let voltage = (avg * 3300) / 4095;
+
+        let duty_as_pct = (duty - MIN_DUTY) as u32 * 100;
+        let duty_as_pct = duty_as_pct / (0xFFFF - MIN_DUTY) as u32;
+
+        let new_power = (voltage * (1 + voltage / 100)) * duty_as_pct;
+
+        tick = (tick + 1) % 20;
+
+        if tick == 0 {
+            info!(
+                "{} duty, {}mV, {} power, {} peak",
+                duty_as_pct, voltage, new_power, peak_v
+            );
+        }
+
+        if duty_as_pct == 0 || voltage > peak_v {
+            peak_v = voltage;
+        }
+
+        duty = duty.wrapping_add(1000);
+        duty = MIN_DUTY.max(duty);
+        // if voltage > (90 * peak_v) / 100 || new_power >= power {
+        //     duty = duty.saturating_add(33);
+        // } else {
+        //     duty = MIN_DUTY.max(duty - 32);
+        // }
+
+        power = new_power;
     }
 }