Files
oled-counter-esp32/main/main.c
Elias Ahokas 901b8b4362 init display
2025-10-15 20:23:05 +03:00

100 lines
2.9 KiB
C

#include <stdio.h>
#include "driver/i2c_master.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#define I2C_SCL 1 /*FIXME*/
#define I2C_SDA 2
/* Docs: https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf */
#define DISP_ADDRESS 0X3c
#define I2C_FREQ 100000
static i2c_master_dev_handle_t disp_handle;
void init_i2c(void){
i2c_master_bus_config_t i2c_mst_config = {
.clk_source = I2C_CLK_SRC_DEFAULT,
.i2c_port = I2C_PORT_NUM_0,
.scl_io_num = I2C_SCL,
.sda_io_num = I2C_SDA,
.glitch_ignore_cnt = 7,
.flags.enable_internal_pullup = true,
};
i2c_master_bus_handle_t bus_handle;
ESP_ERROR_CHECK(i2c_new_master_bus(&i2c_mst_config, &bus_handle));
i2c_device_config_t dev_cfg = {
.dev_addr_length = I2C_ADDR_BIT_LEN_7,
.device_address = DISP_ADDRESS,
.scl_speed_hz = I2C_FREQ,
};
ESP_ERROR_CHECK(i2c_master_bus_add_device(bus_handle, &dev_cfg, &disp_handle));
}
void i2c_disp_send_cmd(uint8_t cmd){
uint8_t data[2] = {0x00, cmd}; /*command mode*/
ESP_ERROR_CHECK(
i2c_master_transmit(disp_handle, data, sizeof(data), pdMS_TO_TICKS(100))
);
}
void i2c_disp_send_data(uint8_t *data, size_t len){
uint8_t *buf = malloc(len + 1);
buf[0] = 0x40; /*data mode*/
memcpy(&buf[1], data, len);
ESP_ERROR_CHECK(
i2c_master_transmit(disp_handle, buf, len + 1, pdMS_TO_TICKS(100)));
free(buf);
}
void init_display(void){
/*according to https://gist.github.com/pulsar256/564fda3b9e8fc6b06b89*/
i2c_disp_send_cmd(0xAE); // Set display OFF
i2c_disp_send_cmd(0xD4); // Set Display Clock Divide Ratio / OSC Frequency
i2c_disp_send_cmd(0x80); // Display Clock Divide Ratio / OSC Frequency
i2c_disp_send_cmd(0xA8); // Set Multiplex Ratio
i2c_disp_send_cmd(0x3F); // Multiplex Ratio for 128x64 (64-1)
i2c_disp_send_cmd(0xD3); // Set Display Offset
i2c_disp_send_cmd(0x00); // Display Offset
i2c_disp_send_cmd(0x40); // Set Display Start Line
i2c_disp_send_cmd(0x8D); // Set Charge Pump
i2c_disp_send_cmd(0x14); // Charge Pump (0x10 External, 0x14 Internal DC/DC)
i2c_disp_send_cmd(0xA1); // Set Segment Re-Map
i2c_disp_send_cmd(0xC8); // Set Com Output Scan Direction
i2c_disp_send_cmd(0xDA); // Set COM Hardware Configuration
i2c_disp_send_cmd(0x12); // COM Hardware Configuration
i2c_disp_send_cmd(0x81); // Set Contrast
i2c_disp_send_cmd(0xCF); // Contrast
i2c_disp_send_cmd(0xD9); // Set Pre-Charge Period
i2c_disp_send_cmd(0xF1); // Set Pre-Charge Period (0x22 External, 0xF1 Internal)
i2c_disp_send_cmd(0xDB); // Set VCOMH Deselect Level
i2c_disp_send_cmd(0x40); // VCOMH Deselect Level
i2c_disp_send_cmd(0xA4); // Set all pixels OFF
i2c_disp_send_cmd(0xA6); // Set display not inverted
i2c_disp_send_cmd(0xAF); // Set display On
}
void app_main(void){
init_i2c();
init_display();
}