From f01ffbcc12c40c68a57bc2daffdfad697bc28921 Mon Sep 17 00:00:00 2001
From: Chen Yuheng <1016867898@qq.com>
Date: Thu, 11 Jul 2024 10:33:43 +0800
Subject: Add oversampling and differential for g4

---
 examples/stm32g4/src/bin/adc_differential.rs | 47 +++++++++++++++++++++++
 examples/stm32g4/src/bin/adc_oversampling.rs | 57 ++++++++++++++++++++++++++++
 2 files changed, 104 insertions(+)
 create mode 100644 examples/stm32g4/src/bin/adc_differential.rs
 create mode 100644 examples/stm32g4/src/bin/adc_oversampling.rs

(limited to 'examples')

diff --git a/examples/stm32g4/src/bin/adc_differential.rs b/examples/stm32g4/src/bin/adc_differential.rs
new file mode 100644
index 000000000..78d071d45
--- /dev/null
+++ b/examples/stm32g4/src/bin/adc_differential.rs
@@ -0,0 +1,47 @@
+//! adc differential mode example
+//!
+//! This example uses adc1 in differential mode
+//! p:pa0 n:pa1
+
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::adc::{Adc, SampleTime};
+use embassy_stm32::Config;
+use embassy_time::Timer;
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let mut config = Config::default();
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.pll = Some(Pll {
+            source: PllSource::HSI,
+            prediv: PllPreDiv::DIV4,
+            mul: PllMul::MUL85,
+            divp: None,
+            divq: None,
+            // Main system clock at 170 MHz
+            divr: Some(PllRDiv::DIV2),
+        });
+        config.rcc.mux.adc12sel = mux::Adcsel::SYS;
+        config.rcc.sys = Sysclk::PLL1_R;
+    }
+    let mut p = embassy_stm32::init(config);
+
+    let mut adc = Adc::new(p.ADC1);
+    adc.set_sample_time(SampleTime::CYCLES247_5);
+    adc.set_differential(&mut p.PA0, true); //p:pa0,n:pa1
+
+    // can also use
+    // adc.set_differential_channel(1, true);
+    info!("adc initialized");
+    loop {
+        let measured = adc.blocking_read(&mut p.PA0);
+        info!("data: {}", measured);
+        Timer::after_millis(500).await;
+    }
+}
diff --git a/examples/stm32g4/src/bin/adc_oversampling.rs b/examples/stm32g4/src/bin/adc_oversampling.rs
new file mode 100644
index 000000000..d31eb20f8
--- /dev/null
+++ b/examples/stm32g4/src/bin/adc_oversampling.rs
@@ -0,0 +1,57 @@
+//! adc oversampling example
+//!
+//! This example uses adc oversampling to achieve 16bit data
+
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::adc::vals::{Rovsm, Trovs};
+use embassy_stm32::adc::{Adc, SampleTime};
+use embassy_stm32::Config;
+use embassy_time::Timer;
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let mut config = Config::default();
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.pll = Some(Pll {
+            source: PllSource::HSI,
+            prediv: PllPreDiv::DIV4,
+            mul: PllMul::MUL85,
+            divp: None,
+            divq: None,
+            // Main system clock at 170 MHz
+            divr: Some(PllRDiv::DIV2),
+        });
+        config.rcc.mux.adc12sel = mux::Adcsel::SYS;
+        config.rcc.sys = Sysclk::PLL1_R;
+    }
+    let mut p = embassy_stm32::init(config);
+
+    let mut adc = Adc::new(p.ADC1);
+    adc.set_sample_time(SampleTime::CYCLES6_5);
+    // From https://www.st.com/resource/en/reference_manual/rm0440-stm32g4-series-advanced-armbased-32bit-mcus-stmicroelectronics.pdf
+    // page652 Oversampler
+    // Table 172. Maximum output results vs N and M. Grayed values indicates truncation
+    // 0x00 oversampling ratio X2
+    // 0x01 oversampling ratio X4
+    // 0x02 oversampling ratio X8
+    // 0x03 oversampling ratio X16
+    // 0x04 oversampling ratio X32
+    // 0x05 oversampling ratio X64
+    // 0x06 oversampling ratio X128
+    // 0x07 oversampling ratio X256
+    adc.set_oversampling_ratio(0x03); // ratio X3
+    adc.set_oversampling_shift(0b0000); // no shift
+    adc.enable_regular_oversampling_mode(Rovsm::RESUMED, Trovs::AUTOMATIC, true);
+
+    loop {
+        let measured = adc.blocking_read(&mut p.PA0);
+        info!("data: 0x{:X}", measured); //max 0xFFF0 -> 65520
+        Timer::after_millis(500).await;
+    }
+}
-- 
cgit