feat: initial

2025-08-12 08:53:40 +03:00
parent 52eab77e54
commit a5b4bf4092
4 changed files with 474 additions and 2 deletions
--- a/README.md
+++ b/README.md
@@ -1,3 +1,131 @@
-# zh_avr_pcf8574
+# FreeRTOS based AVR library for PCF8574(A) 8-bit I/O expander

-AVR library for PCF8574(A) 8-bit I/O expander.
+## Features
+
+1. Support of 16 expanders on one bus.
+2. Support of output and input GPIO's work mode.
+3. Support of interrupts from input GPIO's.
+
+## Note
+
+1. Enable interrupt support only if input GPIO's are used.
+2. All the INT GPIO's on the extenders must be connected to the one GPIO on AVR. Only PORTD4 - PORTD7 are acceptable!
+3. The input GPIO's are always pullup to the power supply.
+
+## Dependencies
+
+1. [zh_avr_free_rtos](http://git.zh.com.ru/avr_libraries/zh_avr_free_rtos)
+2. [zh_avr_vector](http://git.zh.com.ru/avr_libraries/zh_avr_vector)
+3. [zh_avr_common](http://git.zh.com.ru/avr_libraries/zh_avr_common)
+4. [zh_avr_i2c](http://git.zh.com.ru/avr_libraries/zh_avr_i2c)
+
+## Using
+
+In an existing project, run the following command to install the components:
+
+```text
+cd ../your_project/lib
+git clone http://git.zh.com.ru/avr_libraries/zh_avr_free_rtos
+git clone http://git.zh.com.ru/avr_libraries/zh_avr_vector
+git clone http://git.zh.com.ru/avr_libraries/zh_avr_i2c
+git clone http://git.zh.com.ru/avr_libraries/zh_avr_common
+git clone http://git.zh.com.ru/avr_libraries/zh_avr_pcf8574
+```
+
+In the application, add the component:
+
+```c
+#include "zh_avr_pcf8574.h"
+```
+
+## Examples
+
+One expander on bus. All GPIO's as output (except P0 - input). Interrupt is enable:
+
+```c
+#include "avr/io.h"
+#include "stdio.h"
+#include "zh_avr_pcf8574.h"
+
+#define BAUD_RATE 9600
+#define BAUD_PRESCALE (F_CPU / 16 / BAUD_RATE - 1)
+
+int usart(char byte, FILE *stream)
+{
+    while ((UCSR0A & (1 << UDRE0)) == 0)
+    {
+    }
+    UDR0 = byte;
+    return 0;
+}
+FILE uart = FDEV_SETUP_STREAM(usart, NULL, _FDEV_SETUP_WRITE);
+
+zh_avr_pcf8574_handle_t pcf8574_handle = {0};
+
+void print_gpio_status(const char *message, uint8_t reg)
+{
+    printf("%s", message);
+    for (uint8_t i = 0; i < 8; ++i)
+    {
+        printf("%c", (reg & 0x80) ? '1' : '0');
+        reg <<= 1;
+    }
+    printf(".\n");
+}
+
+void pcf8574_example_task(void *pvParameters)
+{
+    zh_avr_i2c_master_init(false);
+    zh_avr_pcf8574_init_config_t pcf8574_init_config = ZH_AVR_PCF8574_INIT_CONFIG_DEFAULT();
+    pcf8574_init_config.i2c_address = 0x38;
+    pcf8574_init_config.p0_gpio_work_mode = true; // Required only for input GPIO.
+    pcf8574_init_config.interrupt_gpio = PORTD4;  // Required only if used input GPIO interrupts.
+    zh_avr_pcf8574_init(&pcf8574_init_config, &pcf8574_handle);
+    uint8_t reg = 0;
+    zh_avr_pcf8574_read(&pcf8574_handle, &reg);
+    print_gpio_status("GPIO status: ", reg);
+    printf("Set P7 to 1, P1 to 1 and P0 to 0.\n");
+    zh_avr_pcf8574_write(&pcf8574_handle, 0b10000010); // GPIO P0 will not be changed because it is operating in input mode.
+    zh_avr_pcf8574_read(&pcf8574_handle, &reg);
+    print_gpio_status("GPIO status: ", reg);
+    printf("Sets P0 to 0.\n");
+    zh_avr_pcf8574_write_gpio(&pcf8574_handle, 0, false); // GPIO P0 will not be changed because it is operating in input mode.
+    bool gpio = 0;
+    zh_avr_pcf8574_read_gpio(&pcf8574_handle, 0, &gpio);
+    printf("P0 status: %d.\n", gpio);
+    printf("Set P1 to 0.\n");
+    zh_avr_pcf8574_write_gpio(&pcf8574_handle, 1, false);
+    zh_avr_pcf8574_read_gpio(&pcf8574_handle, 1, &gpio);
+    printf("P1 status: %d.\n", gpio);
+    zh_avr_pcf8574_read(&pcf8574_handle, &reg);
+    print_gpio_status("GPIO status: ", reg);
+    printf("Reset all GPIO.\n");
+    zh_avr_pcf8574_reset(&pcf8574_handle);
+    zh_avr_pcf8574_read(&pcf8574_handle, &reg);
+    print_gpio_status("GPIO status: ", reg);
+    printf("Task Remaining Stack Size %d.\n", uxTaskGetStackHighWaterMark(NULL));
+    vTaskDelete(NULL);
+}
+int main(void)
+{
+    UBRR0H = (BAUD_PRESCALE >> 8);
+    UBRR0L = BAUD_PRESCALE;
+    UCSR0B = (1 << RXEN0) | (1 << TXEN0);
+    UCSR0C = (1 << UCSZ01) | (1 << UCSZ00);
+    stdout = &uart;
+    xTaskCreate(pcf8574_example_task, "pcf8574 example task", 124, NULL, tskIDLE_PRIORITY, NULL);
+    vTaskStartScheduler();
+    return 0;
+}
+
+void zh_avr_pcf8574_event_handler(zh_avr_pcf8574_event_on_isr_t *event) // Required only if used input GPIO interrupts.
+{
+    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);
+    printf("Interrupt Task Remaining Stack Size %d.\n", uxTaskGetStackHighWaterMark(NULL));
+}
+
+ISR(PCINT2_vect) // Required only if used input GPIO interrupts.
+{
+    zh_avr_pcf8574_isr_handler();
+}
+```