diff --git a/examples/stm32l0/src/bin/async-tsc.rs b/examples/stm32l0/src/bin/async-tsc.rs new file mode 100644 index 000000000..c40b86af9 --- /dev/null +++ b/examples/stm32l0/src/bin/async-tsc.rs @@ -0,0 +1,122 @@ +// Example of async TSC (Touch Sensing Controller) that lights an LED when touch is detected. +// +// Suggested physical setup on STM32L073RZ 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::bind_interrupts; +use embassy_stm32::gpio::{Level, Output, Speed}; +use embassy_stm32::tsc::{self, *}; +use embassy_time::Timer; +use {defmt_rtt as _, panic_probe as _}; + +bind_interrupts!(struct Irqs { + TSC => InterruptHandler; +}); + +#[cortex_m_rt::exception] +unsafe fn HardFault(_: &cortex_m_rt::ExceptionFrame) -> ! { + cortex_m::peripheral::SCB::sys_reset(); +} + +/// This example is written for the nucleo-stm32l073rz, with a stm32l073rz chip. +/// +/// Make sure you check/update the following (whether you use the L073RZ or another board): +/// +/// * [ ] Update .cargo/config.toml with the correct `probe-rs run --chip STM32L073RZTx`chip name. +/// * [ ] Update Cargo.toml to have the correct `embassy-stm32` feature, for L073RZ it should be `stm32l073rz`. +/// * [ ] 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 config = tsc::Config { + ct_pulse_high_length: ChargeTransferPulseCycle::_4, + ct_pulse_low_length: ChargeTransferPulseCycle::_4, + spread_spectrum: false, + spread_spectrum_deviation: SSDeviation::new(2).unwrap(), + spread_spectrum_prescaler: false, + pulse_generator_prescaler: PGPrescalerDivider::_16, + 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 = PinGroup::new(); + g1.set_io1(context.PA0, PinType::Sample); + g1.set_io2(context.PA1, PinType::Channel); + + let mut touch_controller = tsc::Tsc::new_async( + context.TSC, + Some(g1), + None, + None, + None, + None, + None, + None, + None, + config, + Irqs, + ); + + // Check if TSC is ready + if touch_controller.get_state() != State::Ready { + info!("TSC not ready!"); + loop {} // Halt execution + } + info!("TSC initialized successfully"); + + // LED2 on the STM32L073RZ nucleo-board (PA5) + let mut led = Output::new(context.PA5, Level::High, Speed::Low); + + // smaller sample capacitor discharge faster and can be used with shorter delay. + let discharge_delay = 5; // ms + + info!("Starting touch_controller interface"); + loop { + touch_controller.start(); + touch_controller.pend_for_acquisition().await; + 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(), + } + } +}