add blocking TSC examples

1 files changed, 98 insertions, 0 deletions

diff --git a/examples/stm32f3/src/bin/blocking-tsc.rs b/examples/stm32f3/src/bin/blocking-tsc.rs
new file mode 100644
index 000000000..5c8dac94f
--- /dev/null
+++ b/examples/stm32f3/src/bin/blocking-tsc.rs
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+// Example of polling TSC (Touch Sensing Controller) that lights an LED when touch is detected.
+//
+// Suggested physical setup on STM32F303ZE Nucleo board:
+// - Connect a 1000pF capacitor between pin A0 and GND. This is your sampling capacitor.
+// - Connect one end of a 1K resistor to pin A1 and leave the other end loose.
+//   The loose end will act as touch sensor which will register your touch.
+//
+// Troubleshooting the setup:
+// - If no touch seems to be registered, then try to disconnect the sampling capacitor from GND momentarily,
+//   now the led should light up. Next try using a different value for the sampling capacitor.
+//   Also experiment with increasing the values for `ct_pulse_high_length`, `ct_pulse_low_length`, `pulse_generator_prescaler`, `max_count_value` and `discharge_delay`.
+//
+// All configuration values and sampling capacitor value have been determined experimentally.
+// Suitable configuration and discharge delay values are highly dependent on the value of the sample capacitor. For example, a shorter discharge delay can be used with smaller capacitor values.
+//
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_stm32::gpio::{Level, Output, Speed};
+use embassy_stm32::tsc::{self, *};
+use embassy_time::Timer;
+use {defmt_rtt as _, panic_probe as _};
+
+/// This example is written for the nucleo-stm32f303ze, with a stm32f303ze chip.
+///
+/// Make sure you check/update the following (whether you use the F303ZE or another board):
+///
+/// * [ ] Update .cargo/config.toml with the correct `probe-rs run --chip STM32F303ZETx`chip name.
+/// * [ ] Update Cargo.toml to have the correct `embassy-stm32` feature, for F303ZE it should be `stm32f303ze`.
+/// * [ ] If your board has a special clock or power configuration, make sure that it is
+///       set up appropriately.
+/// * [ ] If your board has different pin mapping, update any pin numbers or peripherals
+///       to match your schematic
+///
+/// If you are unsure, please drop by the Embassy Matrix chat for support, and let us know:
+///
+/// * Which example you are trying to run
+/// * Which chip and board you are using
+///
+/// Embassy Chat: https://matrix.to/#/#embassy-rs:matrix.org
+#[embassy_executor::main]
+async fn main(_spawner: embassy_executor::Spawner) {
+    let device_config = embassy_stm32::Config::default();
+    let context = embassy_stm32::init(device_config);
+
+    let tsc_conf = Config {
+        ct_pulse_high_length: ChargeTransferPulseCycle::_8,
+        ct_pulse_low_length: ChargeTransferPulseCycle::_8,
+        spread_spectrum: false,
+        spread_spectrum_deviation: SSDeviation::new(2).unwrap(),
+        spread_spectrum_prescaler: false,
+        pulse_generator_prescaler: PGPrescalerDivider::_32,
+        max_count_value: MaxCount::_255,
+        io_default_mode: false,
+        synchro_pin_polarity: false,
+        acquisition_mode: false,
+        max_count_interrupt: false,
+        channel_ios: TscIOPin::Group1Io1.into(),
+        shield_ios: 0, // no shield
+        sampling_ios: TscIOPin::Group1Io2.into(),
+    };
+
+    let mut g1: PinGroup<embassy_stm32::peripherals::TSC, G1> = PinGroup::new();
+    g1.set_io1(context.PA0, PinType::Sample);
+    g1.set_io2(context.PA1, PinType::Channel);
+
+    let mut touch_controller = tsc::Tsc::new_blocking(context.TSC, Some(g1), None, None, None, None, None, tsc_conf);
+
+    // LED2 on the STM32F303ZE nucleo-board
+    let mut led = Output::new(context.PB7, Level::High, Speed::Low);
+
+    // smaller sample capacitor discharge faster and can be used with shorter delay.
+    let discharge_delay = 5; // ms
+
+    // the interval at which the loop polls for new touch sensor values
+    let polling_interval = 100; // ms
+
+    info!("polling for touch");
+    loop {
+        touch_controller.start();
+        touch_controller.poll_for_acquisition();
+        touch_controller.discharge_io(true);
+        Timer::after_millis(discharge_delay).await;
+
+        let grp1_status = touch_controller.group_get_status(Group::One);
+        match grp1_status {
+            GroupStatus::Complete => {
+                let group_one_val = touch_controller.group_get_value(Group::One);
+                info!("{}", group_one_val);
+                led.set_high();
+            }
+            GroupStatus::Ongoing => led.set_low(),
+        }
+
+        Timer::after_millis(polling_interval).await;
+    }
+}