bouton_isr.c
In ESP-IDF a button is watched by interrupt: the ISR fires on the edge, the task prints. IRAM_ATTR is mandatory because flash may be unavailable during the interrupt.
Hardware required
An ESP32-H2 board (RISC-V 96 MHz, IEEE 802.15.4 radio only — no Wi-Fi) such as a DevKitM-1, powered over USB. 1 push button to GND (GPIO9 doubles as BOOT: short presses fine).
Wiring
Button between GPIO9 and GND; the pull-up is enabled in gpio_config. Any GPIO-matrix pin works.
How it works
gpio_config arms the falling-edge interrupt; the ISR only increments a volatile counter (golden rule: short ISR). The task compares and prints at 20 Hz, filtering bounce. Program it with ESP-IDF (idf.py set-target esp32h2); the USB-Serial/JTAG port (GPIO26/27) acts as console and flash port. Hold Boot + Reset for download mode if needed.
Going further
Wake the SoC with the same interrupt (esp_sleep_enable_ext0_wakeup) for a battery-powered detector.
bouton_isr.c
// bouton_isr.c — interruption sur front, compte les appuis.
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"
#include "esp_log.h"
#define BROCHE 9 // bouton vers GND (GPIO9 = BOOT du DevKit)
static volatile int appuis = 0;
static const char *TAG = "bouton";
static void IRAM_ATTR sur_appui(void *arg)
{
appuis++; // le minimum en contexte d'ISR
}
void app_main(void)
{
gpio_config_t io = {
.pin_bit_mask = 1ULL << BROCHE,
.mode = GPIO_MODE_INPUT,
.pull_up_en = GPIO_PULLUP_ENABLE,
.intr_type = GPIO_INTR_NEGEDGE, // front descendant = appui
};
gpio_config(&io);
gpio_install_isr_service(0);
gpio_isr_handler_add(BROCHE, sur_appui, NULL);
int vu = 0;
while (1) {
if (vu != appuis) { vu = appuis; ESP_LOGI(TAG, "appui n°%d", vu); }
vTaskDelay(pdMS_TO_TICKS(50)); // anti-rebond par echantillonnage
}
}