How to use more that 4 buttons??

[sosse]

Is there any way to use more than 4 buttons using app_button or BSP library? It seems that GPIOTE can handle only 4 pin. Am I right??

	uint32_t err_code;
// Button configuration structure.
static app_button_cfg_t p_button[] = {  {BUTTON_1, APP_BUTTON_ACTIVE_LOW, NRF_GPIO_PIN_PULLUP, button_handler},
                                        {BUTTON_2, APP_BUTTON_ACTIVE_LOW, NRF_GPIO_PIN_PULLUP, button_handler},
                                        {BUTTON_3, APP_BUTTON_ACTIVE_LOW, NRF_GPIO_PIN_PULLUP, button_handler},
                                        {BUTTON_4, APP_BUTTON_ACTIVE_LOW, NRF_GPIO_PIN_PULLUP, button_handler}};

// Initializing the buttons.
err_code = app_button_init(p_button, sizeof(p_button) / sizeof(p_button[0]), 50);
APP_ERROR_CHECK(err_code);
											
// Enabling the buttons.										
err_code = app_button_enable();
APP_ERROR_CHECK(err_code);

My part of code is like this. I want to add BUTTON_5 using same button_handler. How can I add to it?? Thank you.

[Sigurd]

Error code 4 is «NRF_ERROR_NO_MEM”, and is thrown when channel_port_alloc(...) is called and there are no more available GPIOTE channels that could be assigned to the button. In sdk_config.h, you have to increase GPIOTE_CONFIG_NUM_OF_LOW_POWER_EVENTS to 5.

[sosse]

Thank for your answer. Is there any max number of it?? I can also set it as the whole 32 pin as GPIOTE_CONFIG_NUM_OF_LOW_POWER_EVENTS ?? And I wonder that how much the power consumption is increased by increasing the number of it.

[Sigurd]

GPIOTE_CONFIG_NUM_OF_LOW_POWER_EVENTS is the number of low-power input pins, so you should only set it to the actually number of low-power input pins you use.