From 0f2db7e6e0303abef9deb29c4e4243e56a54c795 Mon Sep 17 00:00:00 2001
From: Sachymetsu <sachymetsu@tutamail.com>
Date: Thu, 27 Aug 2026 08:49:34 +0200
Subject: [PATCH] Use ADC oversampling

---
 src/adc.rs | 51 +++++++++++++++++++--------------------------------
 1 file changed, 19 insertions(+), 32 deletions(-)

diff --git a/src/adc.rs b/src/adc.rs
index 5e30d18..fc5697b 100644
--- a/src/adc.rs
+++ b/src/adc.rs
@@ -1,9 +1,9 @@
+use embassy_futures::join::join;
 use embassy_nrf::{
     Peri,
     gpio::{Level, Output, OutputDrive},
-    peripherals,
-    pwm::{self, DutyCycle, SimpleConfig, SimplePwm},
-    saadc::{self, ChannelConfig, Config, Resolution, Saadc},
+    peripherals, pwm,
+    saadc::{self, ChannelConfig, Saadc},
 };
 use embassy_time::Timer;
 use sachy_battery::BatteryDischargeProfile;
@@ -52,10 +52,10 @@ fn to_volts(sample: i16, reference: f32) -> f32 {
 fn init_pwm<'scope>(
     pwm: Peri<'scope, peripherals::PWM0>,
     ch0: Peri<'scope, peripherals::P0_05>,
-) -> SimplePwm<'scope> {
-    let mut config = SimpleConfig::default();
+) -> pwm::SimplePwm<'scope> {
+    let mut config = pwm::SimpleConfig::default();
     config.prescaler = pwm::Prescaler::Div1;
-    let pwm_ctrl = SimplePwm::new_1ch(pwm, ch0, &config);
+    let pwm_ctrl = pwm::SimplePwm::new_1ch(pwm, ch0, &config);
     pwm_ctrl.set_period(2_000_000);
 
     pwm_ctrl
@@ -73,8 +73,9 @@ fn init_saadc<'scope>(
 
     let bat_config = ChannelConfig::single_ended(saadc::VddInput);
 
-    let mut saadc_config = Config::default();
-    saadc_config.resolution = Resolution::_10bit;
+    let mut saadc_config = saadc::Config::default();
+    saadc_config.resolution = saadc::Resolution::_10bit;
+    saadc_config.oversample = saadc::Oversample::Over16x;
 
     Saadc::new(
         saadc,
@@ -93,9 +94,9 @@ pub async fn task(
     mut pwm: Peri<'static, peripherals::PWM0>,
     mut pin5: Peri<'static, peripherals::P0_05>,
 ) {
-    static ADC_BUFFER: ConstStaticCell<[i16; 3]> = ConstStaticCell::new([0; 3]);
-    let adc_buf = ADC_BUFFER.take();
+    static ADC_SAMPLE_BUFFER: ConstStaticCell<[i16; 3]> = ConstStaticCell::new([0; 3]);
 
+    let sample_buf = ADC_SAMPLE_BUFFER.take();
     let mut measure = unwrap!(START_MEASUREMENTS.receiver());
 
     loop {
@@ -107,36 +108,22 @@ pub async fn task(
 
         photo_ctrl.set_high();
         pwm_ctrl.enable();
-        pwm_ctrl.set_duty(0, DutyCycle::normal(4));
-        saadc.calibrate().await;
+        pwm_ctrl.set_duty(0, pwm::DutyCycle::normal(4));
 
-        Timer::after_millis(30).await;
+        join(saadc.calibrate(), Timer::after_millis(30)).await;
 
-        let mut acc_buf = [0; 3];
-        let divisor = 4;
-
-        for _ in 0..divisor {
-            saadc.sample(adc_buf).await;
-            acc_buf
-                .iter_mut()
-                .zip(adc_buf.iter())
-                .for_each(|(slot, &value)| *slot += value);
-            Timer::after_millis(5).await;
-        }
+        saadc.sample(sample_buf).await;
 
         photo_ctrl.set_low();
-        pwm_ctrl.set_duty(0, DutyCycle::normal(0));
-        pwm_ctrl.disable();
+        pwm_ctrl.set_duty(0, pwm::DutyCycle::normal(0));
 
         drop((pwm_ctrl, saadc, photo_ctrl));
 
-        acc_buf.iter_mut().for_each(|acc| *acc /= divisor);
-
-        let [soil, light, bat] = acc_buf;
+        let [soil, light, bat] = *sample_buf;
 
         let bat_volt = to_volts(bat, VREF);
 
-        let (soil, light, bat) = (
+        let (soil, light, bat_pct) = (
             calculate_soil_moisture(bat_volt, soil),
             calculate_lux(to_volts(light, VREF)).max(0.0),
             BatteryDischargeProfile::calc_pct_from_profile_range(
@@ -145,9 +132,9 @@ pub async fn task(
             ),
         );
 
-        let measurements = AdcMeasurements::new(bat, bat_volt, soil, light);
+        let measurements = AdcMeasurements::new(bat_pct, bat_volt, soil, light);
 
-        info!("Soil {}, Light {}, Bat {}", soil, light, bat);
+        info!("Soil {}, Light {}, Bat {}", soil, light, bat_pct);
 
         ADC_MEASUREMENT.signal(measurements);
     }
-- 
2.51.2