115 lines
4.1 KiB
Markdown
115 lines
4.1 KiB
Markdown
# ESP32 ESP-IDF component for PCF8574(A) 8-bit I/O expander
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## Tested on
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1. [ESP32 ESP-IDF v5.5.1](https://docs.espressif.com/projects/esp-idf/en/v5.5.1/esp32/index.html)
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## Features
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1. Support of 16 expanders on one bus.
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2. Support of output and input GPIO's work mode.
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3. Support of interrupts from input GPIO's.
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## Note
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1. Enable interrupt support only if input GPIO's are used.
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2. All the INT GPIO's on the extenders must be connected to the one GPIO on ESP.
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3. The input GPIO's are always pullup to the power supply.
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## Dependencies
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1. [zh_vector](http://git.zh.com.ru/esp_components/zh_vector)
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## Using
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In an existing project, run the following command to install the components:
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```text
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cd ../your_project/components
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git clone http://git.zh.com.ru/esp_components/zh_pcf8574
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git clone http://git.zh.com.ru/esp_components/zh_vector
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```
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In the application, add the component:
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```c
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#include "zh_pcf8574.h"
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```
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## Examples
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One expander on bus. All GPIO's as output (except P0 - input). Interrupt is enable:
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```c
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#include "zh_pcf8574.h"
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#define I2C_PORT (I2C_NUM_MAX - 1)
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i2c_master_bus_handle_t i2c_bus_handle = NULL;
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zh_pcf8574_handle_t pcf8574_handle = {0};
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void zh_pcf8574_event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data); // Required only if used input GPIO interrupts.
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void print_gpio_status(const char *message, uint8_t reg)
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{
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printf("%s", message);
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for (uint8_t i = 0; i < 8; ++i)
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{
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printf("%c", (reg & 0x80) ? '1' : '0');
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reg <<= 1;
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}
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printf(".\n");
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}
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void app_main(void)
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{
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esp_log_level_set("zh_pcf8574", ESP_LOG_ERROR);
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esp_log_level_set("zh_vector", ESP_LOG_ERROR);
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i2c_master_bus_config_t i2c_bus_config = {
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.clk_source = I2C_CLK_SRC_DEFAULT,
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.i2c_port = I2C_PORT,
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.scl_io_num = GPIO_NUM_22,
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.sda_io_num = GPIO_NUM_21,
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.glitch_ignore_cnt = 7,
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.flags.enable_internal_pullup = true,
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};
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i2c_new_master_bus(&i2c_bus_config, &i2c_bus_handle);
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esp_event_loop_create_default(); // Required only if used input GPIO interrupts.
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esp_event_handler_instance_register(ZH_PCF8574, ESP_EVENT_ANY_ID, &zh_pcf8574_event_handler, NULL, NULL); // Required only if used input GPIO interrupts.
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zh_pcf8574_init_config_t pcf8574_init_config = ZH_PCF8574_INIT_CONFIG_DEFAULT();
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pcf8574_init_config.i2c_handle = i2c_bus_handle;
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pcf8574_init_config.i2c_address = 0x38;
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pcf8574_init_config.p0_gpio_work_mode = true; // Required only for input GPIO.
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pcf8574_init_config.interrupt_gpio = GPIO_NUM_14; // Required only if used input GPIO interrupts.
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zh_pcf8574_init(&pcf8574_init_config, &pcf8574_handle);
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uint8_t reg = 0;
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zh_pcf8574_read(&pcf8574_handle, ®);
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print_gpio_status("GPIO status: ", reg);
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printf("Set P7 to 1, P1 to 1 and P0 to 0.\n");
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zh_pcf8574_write(&pcf8574_handle, 0b10000010); // GPIO P0 will not be changed because it is operating in input mode.
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zh_pcf8574_read(&pcf8574_handle, ®);
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print_gpio_status("GPIO status: ", reg);
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printf("Sets P0 to 0.\n");
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zh_pcf8574_write_gpio(&pcf8574_handle, 0, false); // GPIO P0 will not be changed because it is operating in input mode.
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bool gpio = 0;
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zh_pcf8574_read_gpio(&pcf8574_handle, 0, &gpio);
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printf("P0 status: %d.\n", gpio);
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printf("Set P1 to 0.\n");
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zh_pcf8574_write_gpio(&pcf8574_handle, 1, false);
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zh_pcf8574_read_gpio(&pcf8574_handle, 1, &gpio);
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printf("P1 status: %d.\n", gpio);
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zh_pcf8574_read(&pcf8574_handle, ®);
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print_gpio_status("GPIO status: ", reg);
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printf("Reset all GPIO.\n");
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zh_pcf8574_reset(&pcf8574_handle);
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zh_pcf8574_read(&pcf8574_handle, ®);
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print_gpio_status("GPIO status: ", reg);
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}
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void zh_pcf8574_event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data) // Required only if used input GPIO interrupts.
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{
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zh_pcf8574_event_on_isr_t *event = event_data;
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printf("Interrupt happened on device address 0x%02X on GPIO number %d at level %d.\n", event->i2c_address, event->gpio_number, event->gpio_level);
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}
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```
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