Matrix keypad library (CON-370)

[jonsmirl]

Is there a library implementing 4x4 matrix keypads somewhere? We need single click, double click, long press, etc -- just like the ESP IOT Button library but using a keypad matrix. I expected this to be in the ESP IOT solution but I don't see it there.

Like how this is wired... https://programmer.ink/think/stm32-4-4-matrix-keyboard-external-interrupt-trigger-mode.html

Could you please ask the IOT people to add keypad matrix support so that we don't have to write our own? https://espressif-docs.readthedocs-hosted.com/projects/espressif-esp-iot-solution/en/latest/input_device/button.html It should be able to handle any config up to 4x4 like 2x4, 3x3, 3x4, etc.

Looks like the Arduino library has this and the Espressif one doesn't.

[jonsmirl]

This library needs to be interrupt based, the Arduino one is polled. The stm example linked above is interrupt based.

[jonsmirl]

This technique has electrical issues. I am getting cross talk between the buttons due to the high frequency scanning. It may not be workable.

[jonsmirl]

I deleted the previous code, it did not work for more than 2x2 due to cross talk issues on the wires. I am implementing a different technique using interrupts that does not rely on high frequency scanning.

[jonsmirl]

This is my second attempt at matrix keypad support. This is diff off from the espressif_button component (IOT Button). This version is interrupt based. It has a problem with occasionally losing edge interrupts, but it detects that condition and recovers. Please test, improve code, etc. You have my full permission to add this code to IDF which I recommend doing. Arduino, ST, NXP, etc all include matrix keypad support in their IDF.

matrix.zip

static uint8_t key;

static void button_down(void *arg) {
    ESP_LOGI(TAG, "button_down %x", key);
}
static void button_up(void *arg) {
    ESP_LOGI(TAG, "button_up %x", key);
}
static void button_repeat(void *arg) {
    ESP_LOGI(TAG, "button_repeat %x", key);
}
static void button_single(void *arg) {
    ESP_LOGI(TAG, "button_single %x", key);
}
static void button_double(void *arg) {
    ESP_LOGI(TAG, "button_double %x", key);
}
static void button_long_start(void *arg) {
    ESP_LOGI(TAG, "button_long_start %x", key);
}
static void button_long_hold(void *arg) {
    ESP_LOGI(TAG, "button_long_hold %x", key);
}

app_driver_handle_t app_driver_switch_init()
{
    button_config_t cfg = {
        .type = BUTTON_TYPE_MATRIX,
        .matrix_button_config = {
            .row = {4, 5, 7, 0xff},
            .column = {1, 2, 3, 0xff},
            .pKey = &key,
        },
    };
    button_handle_t matrix = iot_button_create(&cfg);
    iot_button_register_cb(matrix, BUTTON_PRESS_DOWN, button_down);
    iot_button_register_cb(matrix, BUTTON_PRESS_UP, button_up);
    iot_button_register_cb(matrix, BUTTON_PRESS_REPEAT, button_repeat);
    iot_button_register_cb(matrix, BUTTON_SINGLE_CLICK, button_single);
    iot_button_register_cb(matrix, BUTTON_DOUBLE_CLICK, button_double);
    iot_button_register_cb(matrix, BUTTON_LONG_PRESS_START, button_long_start);
    iot_button_register_cb(matrix, BUTTON_LONG_PRESS_HOLD, button_long_hold);

[InfiniteYuan]

Thank you for your suggestion.

We'll mark it TODO.

[jonsmirl]

I have solved this locally. I just gave up on using interrupts and resorted polling. That is easy to implement.