hI,
when using the code,
xTaskCreate(&task_ssd1306_display_text, "ssd1306_display_text", 2048,
(void )"Hello world!\nMulitine is OK!\nAnother line", 6, NULL);
following error comes up :
note: expected 'TaskFunction_t {aka void ()(void )}' but argument is of type 'void ()(const void *)'
static inline IRAM_ATTR BaseType_t xTaskCreate(
Can anyone advise why this error pops up , and how to solve it ?
thanks in advance
best regadrs
Ludo

There is no decent SSD1306 library for ESP-IDF but several for Arduino platform. Wemos already have ESP32 model with built-in OLED, so it would be nice to have a native IDF support for the display.

Hey, your clear function inits the zero[128] array but never defines it, which lead to artifacts on my display. Here is the primitive fix you could probably solve way better:

uint8_t zero[128];
for (uint8_t i = 0; i < 128; i++) {
zero[i] = 0;
}

Just adding this comment to your project because from my google search there appears to be a number of people who have searched for an esp-idf based solution to driving this type of display which has been integrated into this board. Heltec themselves however only provide ardinuo based code. It is however very simple to get running, the key thing is a reset needs to be sent to the OLED display for it to start working.

diff --git a/main/main.c b/main/main.c
index 2f35dd2..c1f1776 100644
--- a/main/main.c
+++ b/main/main.c
@@ -11,8 +11,9 @@
 #include "ssd1366.h"
 #include "font8x8_basic.h"
 
-#define SDA_PIN GPIO_NUM_15
-#define SCL_PIN GPIO_NUM_2
+#define SDA_PIN GPIO_NUM_4
+#define SCL_PIN GPIO_NUM_15
+#define RST_PIN GPIO_NUM_16
 
 #define tag "SSD1306"
 
@@ -24,7 +25,7 @@ void i2c_master_init()
                .scl_io_num = SCL_PIN,
                .sda_pullup_en = GPIO_PULLUP_ENABLE,
                .scl_pullup_en = GPIO_PULLUP_ENABLE,
-               .master.clk_speed = 1000000
+               .master.clk_speed = 700000
        };
        i2c_param_config(I2C_NUM_0, &i2c_config);
        i2c_driver_install(I2C_NUM_0, I2C_MODE_MASTER, 0, 0, 0);
@@ -35,6 +36,11 @@ void ssd1306_init() {
 
        i2c_cmd_handle_t cmd = i2c_cmd_link_create();
 
+        gpio_set_direction(RST_PIN,GPIO_MODE_OUTPUT);
+        gpio_set_level(RST_PIN, 0);
+        vTaskDelay( pdMS_TO_TICKS( 100 ) );
+        gpio_set_level(RST_PIN, 1);
+
        i2c_master_start(cmd);
        i2c_master_write_byte(cmd, (OLED_I2C_ADDRESS << 1) | I2C_MASTER_WRITE, true);
        i2c_master_write_byte(cmd, OLED_CONTROL_BYTE_CMD_STREAM, true);

Device: ESP32-WROOM-32

Steps:
Run get_idf in the directory
Run make all to build the app

Compilation crashes after a while with this
CC build/esp_wifi/src/wifi_init.o $IDF_PATH/esp/esp-idf/components/esp_wifi/src/wifi_init.c:32:2: error: #error "WiFi configuration check: WARNING, WIFI_RX_BA_WIN should not be larger than WIFI_DYNAMIC_RX_BUFFER_NUM!" #error "WiFi configuration check: WARNING, WIFI_RX_BA_WIN should not be larger than WIFI_DYNAMIC_RX_BUFFER_NUM!" ^~~~~ make[1]: *** [$IDF_PATH/esp/esp-idf/make/component_wrapper.mk:292: src/wifi_init.o] Error 1 make: *** [$IDF_PATH/esp/esp-idf/make/project.mk:642: component-esp_wifi-build] Error 2