PlatformIO

How to fix PlatformIO mbed error: ‘Mutex’ does not name a type

Problem:

You are trying to compile your PlatformIO mbed application using Mutexes like

Mutex myLock;

but you see an error message like

src\main.cpp:3:1: error: 'Mutex' does not name a type
 Mutex myLock;
 ^~~~~

Solution:

Add this line to your platformio.ini:

build_flags = -D PIO_FRAMEWORK_MBED_RTOS_PRESENT

This will enable the RTOS features in mbed, including the Mutex.

Posted by Uli Köhler in mbed, PlatformIO

How to fix PlatformIO fatal error: stm32f429i_discovery_lcd.h: No such file or directory

Problem:

You are trying to compile your PlatformIO application using  the LCD_DISCO_F429ZI library, but you see an error message like

 #include "stm32f429i_discovery_lcd.h"
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
*** [.pio\build\disco_f429zi\src\main.o] Error 1
In file included from .pio\libdeps\disco_f429zi\LCD_DISCO_F429ZI_ID2432\LCD_DISCO_F429ZI.cpp:19:0:
.pio\libdeps\disco_f429zi\LCD_DISCO_F429ZI_ID2432\LCD_DISCO_F429ZI.h:25:10: fatal error: stm32f429i_discovery_lcd.h: No such file or directory

Solution:

First, ensure that BSP_DISCO_F429ZI is listed is library dependency in platformio.ini like this:

[env:disco_f429zi]
platform = ststm32
board = disco_f429zi
framework = mbed
lib_deps =
    LCD_DISCO_F429ZI
    BSP_DISCO_F429ZI

 

Replace the line

#include "stm32f429i_discovery_lcd.h"

in LCD_DISCO_F429ZI.h with

#include "Drivers/BSP/STM32F429I-Discovery/stm32f429i_discovery_lcd.h"

 

Posted by Uli Köhler in C/C++, PlatformIO

How to fix PlatformIO fatal error: ../Fonts/fonts.h: No such file or directory

Problem:

You are trying to compile a PlatformIO application using the BSP_DISCO_F429ZI library, but you see an error message like

In file included from .pio\libdeps\disco_f429zi\BSP_DISCO_F429ZI_ID2208\Drivers\BSP\STM32F429I-Discovery\stm32f429i_discovery_lcd.c:75:0:
.pio\libdeps\disco_f429zi\BSP_DISCO_F429ZI_ID2208\Drivers\BSP\STM32F429I-Discovery\stm32f429i_discovery_lcd.h:49:10: fatal error: ../Fonts/fonts.h: No such file or directory
 #include "../Fonts/fonts.h"
          ^~~~~~~~~~~~~~~~~~
compilation terminated.

Solution:

The BSP_DISCO_F429ZI package includes fonts.h from the wrong directory. Replace

#include "../Fonts/fonts.h"

by

#include "Utilities/Fonts/fonts.h"

in order to fix the issue. You might need to do that multiple times (in multiple files) in order to fix your build.

Posted by Uli Köhler in C/C++, PlatformIO

Minimal ESP-IDF UART transmit example for ESP32 & PlatformIO

The following example writes the string CAFE to UART continously, waiting for 100ms in between:

#include <driver/gpio.h>
#include <driver/uart.h>
// Include FreeRTOS for delay
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>

int app_main() {
    uart_config_t uart_config = {
        .baud_rate = 115200,
        .data_bits = UART_DATA_8_BITS,
        .parity    = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE
    };
    uart_driver_install(UART_NUM_1, 2048, 0, 0, NULL, 0);
    uart_param_config(UART_NUM_1, &uart_config);
    uart_set_pin(UART_NUM_1, 10, 9, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);

    // Main loop
    while(true) {
        uart_write_bytes(UART_NUM_1, "CAFE", 5);
        vTaskDelay(100 / portTICK_RATE_MS);
    }
}

 

Posted by Uli Köhler in C/C++, Embedded, PlatformIO

ESP-IDF equivalent to Arduino delay()

You can use the FreeRTOS API to provide a delay similar to the Arduino delay() function in the ESP-IDF framework. FreeRTOS is included in the PlatformIO ESP-IDF default configuration.

First, include the FreeRTOS headers

// Include FreeRTOS for delay
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>

After that, you can use vTaskDelay(...) to perform the delay. This example delays by 500ms:

vTaskDelay(500 / portTICK_RATE_MS);

You can use vTaskDelay() even if not using FreeRTOS tasks.

For a full example, refer to PlatformIO ESP-IDF ESP32 blink example

Posted by Uli Köhler in C/C++, Embedded, PlatformIO

How to set pin to output mode using ESP-IDF

Use this snippet to define a pin as output using the ESP-IDF framework (e.g. using PlatformIO):

gpio_config_t io_conf;
io_conf.intr_type = GPIO_PIN_INTR_DISABLE;
io_conf.mode = GPIO_MODE_OUTPUT;
// Define the pin here (e.g. (1ULL << 2) for GPIO9)
io_conf.pin_bit_mask = (1ULL << 2);
io_conf.pull_down_en = 0;
io_conf.pull_up_en = 0;
gpio_config(&io_conf);

The example above configures GPIO2 as an output. Use (1ULL << 3) to configure GPIO3 as an output

Posted by Uli Köhler in C/C++, Embedded, PlatformIO

How to fix ESP-IDF ‘undefined reference to app_main’

Problem:

You are trying to compile your C/C++ ESP8266/ESP32 firmware using the ESP-IDF framework. Your source code looks like this:

int main() {
    // ...
}

but you only see an error message like this:

.platformio/packages/toolchain-xtensa32/bin/../lib/gcc/xtensa-esp32-elf/8.2.0/../../../../xtensa-esp32-elf/bin/ld.exe: .pio\build\nodemcu-32s\esp-idf\esp32\libesp32.a(cpu_start.c.o):(.literal.main_task+0x18): undefined reference to `app_main'
.platformio/packages/toolchain-xtensa32/bin/../lib/gcc/xtensa-esp32-elf/8.2.0/../../../../xtensa-esp32-elf/bin/ld.exe: .pio\build\nodemcu-32s\esp-idf\esp32\libesp32.a(cpu_start.c.o): in function `main_task':
.platformio\packages\framework-espidf\components\esp32/cpu_start.c:540: undefined reference to `app_main'
collect2.exe: error: ld returned 1 exit status
*** [.pio\build\nodemcu-32s\firmware.elf] Error 1

Solution:

For the ESP-IDF framework, the main() function needs to be named app_main():

int app_main() {
    // ...
}

See PlatformIO ESP-IDF ESP32 blink example for a complete example.

Posted by Uli Köhler in C/C++, Embedded, PlatformIO

PlatformIO ESP-IDF ESP32 blink example

This example is the equivalent of the simple Arduino blink example for ESP32 boards when using the ESP-IDF framework:

#include <driver/gpio.h>
// Include FreeRTOS for delay
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>

#define LED 2 // LED connected to GPIO2

int app_main() {
    // Configure pin
    gpio_config_t io_conf;
    io_conf.intr_type = GPIO_PIN_INTR_DISABLE;
    io_conf.mode = GPIO_MODE_OUTPUT;
    io_conf.pin_bit_mask = (1ULL << LED);
    io_conf.pull_down_en = 0;
    io_conf.pull_up_en = 0;
    gpio_config(&io_conf);

    // Main loop
    while(true) {
        gpio_set_level(LED, 0);
        vTaskDelay(500 / portTICK_RATE_MS);
        gpio_set_level(LED, 1);
        vTaskDelay(500 / portTICK_RATE_MS);
    }
}

 

Posted by Uli Köhler in C/C++, Embedded, PlatformIO

How to fix Platform IO “No tasks to run found. Configure tasks…”

If you see this message while trying to run a PlatformIO task like Build or Upload:

No tasks to run found. Configure tasks...

you can fix that easily: Open Preferences: Open settings (JSON) in Visual Studio code (the default keybinding to open the action menu is Ctrl+Shift+P).

Then look for this line:

"task.autoDetect": "off"

and delete it.

Now save the file. You can immediately run PlatformIO tasks after saving settings.json without restarting Visual Studio Code !

Posted by Uli Köhler in PlatformIO

mbed STM32F4DISCOVERY simple LED demo

This demo shows you how to control the STM32F4DISCOVERY LEDs using mbed.
I use mbed from inside PlatformIO.

#include <mbed.h>

DigitalOut greenLED(PD_12);
DigitalOut orangeLED(PD_13);
DigitalOut redLED(PD_14);
DigitalOut blueLED(PD_15);

int main() {
  while(1) {
    // Cycle LEDs in order
    // NOTE: You can toggle a LED using
    //  blueLED = !blueLED;
    blueLED = 0;
    greenLED = 1;
    wait(0.25);
    greenLED = 0;
    orangeLED = 1;
    wait(0.25);
    orangeLED = 0;
    redLED = 1;
    wait(0.25);
    redLED = 0;
    blueLED = 1;
    wait(0.25);
  }
}

 

Posted by Uli Köhler in mbed, PlatformIO