Add OLED display support

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "src/BME68x-Sensor-API"]
 	path = src/BME68x-Sensor-API
 	url = https://github.com/BoschSensortec/BME68x-Sensor-API.git
+[submodule "src/oled-driver"]
+	path = src/oled-driver
+	url = git@github.com:MG-5/oled-driver.git

.vscode/c_cpp_properties.json

@@ -11,15 +11,18 @@
                 "${workspaceFolder}/cubemx/Middlewares/Third_Party/FreeRTOS/Source/CMSIS_RTOS_V2",
                 "${workspaceFolder}/cubemx/Middlewares/Third_Party/FreeRTOS/Source/portable/GCC/ARM_CM3",
                 "${workspaceFolder}/cubemx/Drivers/CMSIS/Device/ST/STM32L1xx/Include",
-                "${workspaceFolder}/cubemx/Drivers/CMSIS/Include"
+                "${workspaceFolder}/cubemx/Drivers/CMSIS/Include",
+                "${workspaceFolder}/src",
+                "${workspaceFolder}/src/oled-driver/include",
+                "${workspaceFolder}/src/oled-driver"
             ],
             "defines": [
-                "STM32L1",
+                "DEBUG",
-                "STM32L152RC",
                 "STM32L152xC",
-                "BME68X_DO_NOT_USE_FPU"
+                "BME68X_DO_NOT_USE_FPU",
+                "FW_USE_RTOS"
             ],
-            "compilerPath": "arm-none-eabi-gcc",
+            "compilerPath": "/usr/bin/arm-none-eabi-gcc",
             "cStandard": "c11",
             "cppStandard": "c++17"
         }

Makefile

@@ -2,17 +2,24 @@ TARGET	:= voc-sensor
 RTOS    := freertos
 DEVICE	:= stm32l152rc
 
-DEFS := BME68X_DO_NOT_USE_FPU
+DEFS    += BME68X_DO_NOT_USE_FPU
+DEFS    += FW_USE_RTOS
 
 INCDIRS			:=      \
+src/BME68x-Sensor-API   \
+src/oled-driver/        \
+src/oled-driver/include \
 src 				    \
-src/BME68x-Sensor-API
 
 SOURCES			:=		            \
+src/BME68x-Sensor-API/bme68x.c      \
+src/oled-driver/fonts/mono.cxx     \
+src/oled-driver/src/Display.cxx     \
+src/oled-driver/src/Image.cxx       \
+src/oled-driver/src/Renderer.cxx    \
 src/bmeSPI.cxx                      \
-src/main.cxx                \
 src/handlers.cxx                    \
-src/BME68x-Sensor-API/bme68x.c
+src/main.cxx                        \
 
 # Actual build engine
 include core/mk/include.mk

core/src/abi.cpp

@@ -13,7 +13,13 @@ void *operator new(std::size_t size)
 #if FW_USE_RTOS
     return pvPortMalloc(size);
 #else
-    return reinterpret_cast<void *>(0xffffffff);
+#ifdef DEBUG
+    __asm("bkpt");
+#else
+    while (1)
+    {
+    }
+#endif
 #endif
 }
 
@@ -26,11 +32,15 @@ void operator delete(void *ptr)
 {
 #if FW_USE_RTOS
     vPortFree(ptr);
+#else
+#ifdef DEBUG
+    __asm("bkpt");
 #else
     while (1)
     {
     }
 #endif
+#endif
 }
 
 void operator delete(void *ptr, unsigned int)
@@ -110,7 +120,7 @@ extern "C"
 
     // some functions in cmath follow the compiler flag -fno-math-errno
     // but not so for std::pow...
-    void __errno() {
+    void __errno()
-        
+    {
     }
 }

cubemx/Core/Inc/FreeRTOSConfig.h

@@ -60,7 +60,7 @@
 #define configTICK_RATE_HZ                       ((TickType_t)1000)
 #define configMAX_PRIORITIES                     ( 56 )
 #define configMINIMAL_STACK_SIZE                 ((uint16_t)128)
-#define configTOTAL_HEAP_SIZE                    ((size_t)3072)
+#define configTOTAL_HEAP_SIZE                    ((size_t)6000)
 #define configMAX_TASK_NAME_LEN                  ( 16 )
 #define configUSE_TRACE_FACILITY                 1
 #define configUSE_16_BIT_TICKS                   0
@@ -68,8 +68,10 @@
 #define configQUEUE_REGISTRY_SIZE                8
 #define configCHECK_FOR_STACK_OVERFLOW           2
 #define configUSE_RECURSIVE_MUTEXES              1
+#define configUSE_MALLOC_FAILED_HOOK             1
 #define configUSE_COUNTING_SEMAPHORES            1
 #define configUSE_PORT_OPTIMISED_TASK_SELECTION  0
+#define configRECORD_STACK_HIGH_ADDRESS          1
 
 /* Co-routine definitions. */
 #define configUSE_CO_ROUTINES                    0

cubemx/Core/Inc/main.h

@@ -58,8 +58,14 @@ void Error_Handler(void);
 /* USER CODE END EFP */
 
 /* Private defines -----------------------------------------------------------*/
-#define SPI_CS_Pin GPIO_PIN_12
+#define VocSensorCS_Pin GPIO_PIN_0
-#define SPI_CS_GPIO_Port GPIOB
+#define VocSensorCS_GPIO_Port GPIOA
+#define DisplayDC_Pin GPIO_PIN_10
+#define DisplayDC_GPIO_Port GPIOB
+#define DisplayReset_Pin GPIO_PIN_11
+#define DisplayReset_GPIO_Port GPIOB
+#define DisplayCS_Pin GPIO_PIN_12
+#define DisplayCS_GPIO_Port GPIOB
 /* USER CODE BEGIN Private defines */
 
 /* USER CODE END Private defines */

cubemx/Core/Src/freertos.c

@@ -75,6 +75,7 @@ void MX_FREERTOS_Init(void); /* (MISRA C 2004 rule 8.1) */
 
 /* Hook prototypes */
 void vApplicationStackOverflowHook(xTaskHandle xTask, signed char *pcTaskName);
+void vApplicationMallocFailedHook(void);
 
 /* USER CODE BEGIN 4 */
 __weak void vApplicationStackOverflowHook(xTaskHandle xTask, signed char *pcTaskName)
@@ -85,6 +86,22 @@ __weak void vApplicationStackOverflowHook(xTaskHandle xTask, signed char *pcTask
 }
 /* USER CODE END 4 */
 
+/* USER CODE BEGIN 5 */
+__weak void vApplicationMallocFailedHook(void)
+{
+   /* vApplicationMallocFailedHook() will only be called if
+   configUSE_MALLOC_FAILED_HOOK is set to 1 in FreeRTOSConfig.h. It is a hook
+   function that will get called if a call to pvPortMalloc() fails.
+   pvPortMalloc() is called internally by the kernel whenever a task, queue,
+   timer or semaphore is created. It is also called by various parts of the
+   demo application. If heap_1.c or heap_2.c are used, then the size of the
+   heap available to pvPortMalloc() is defined by configTOTAL_HEAP_SIZE in
+   FreeRTOSConfig.h, and the xPortGetFreeHeapSize() API function can be used
+   to query the size of free heap space that remains (although it does not
+   provide information on how the remaining heap might be fragmented). */
+}
+/* USER CODE END 5 */
+
 /**
   * @brief  FreeRTOS initialization
   * @param  None

cubemx/Core/Src/gpio.c

@@ -53,7 +53,10 @@ void MX_GPIO_Init(void)
   __HAL_RCC_GPIOD_CLK_ENABLE();
 
   /*Configure GPIO pin Output Level */
-  HAL_GPIO_WritePin(SPI_CS_GPIO_Port, SPI_CS_Pin, GPIO_PIN_RESET);
+  HAL_GPIO_WritePin(VocSensorCS_GPIO_Port, VocSensorCS_Pin, GPIO_PIN_RESET);
+
+  /*Configure GPIO pin Output Level */
+  HAL_GPIO_WritePin(GPIOB, DisplayDC_Pin|DisplayReset_Pin|DisplayCS_Pin, GPIO_PIN_RESET);
 
   /*Configure GPIO pins : PC13 PC14 PC15 PC0
                            PC1 PC2 PC3 PC4
@@ -73,34 +76,41 @@ void MX_GPIO_Init(void)
   GPIO_InitStruct.Pull = GPIO_NOPULL;
   HAL_GPIO_Init(GPIOH, &GPIO_InitStruct);
 
-  /*Configure GPIO pins : PA0 PA1 PA2 PA3
+  /*Configure GPIO pin : PtPin */
-                           PA4 PA5 PA6 PA7
+  GPIO_InitStruct.Pin = VocSensorCS_Pin;
-                           PA8 PA9 PA10 PA11
+  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
-                           PA12 PA15 */
+  GPIO_InitStruct.Pull = GPIO_NOPULL;
-  GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3
+  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
-                          |GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7
+  HAL_GPIO_Init(VocSensorCS_GPIO_Port, &GPIO_InitStruct);
-                          |GPIO_PIN_8|GPIO_PIN_9|GPIO_PIN_10|GPIO_PIN_11
+
-                          |GPIO_PIN_12|GPIO_PIN_15;
+  /*Configure GPIO pins : PA1 PA2 PA3 PA4
+                           PA5 PA6 PA7 PA8
+                           PA9 PA10 PA11 PA12
+                           PA15 */
+  GPIO_InitStruct.Pin = GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3|GPIO_PIN_4
+                          |GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7|GPIO_PIN_8
+                          |GPIO_PIN_9|GPIO_PIN_10|GPIO_PIN_11|GPIO_PIN_12
+                          |GPIO_PIN_15;
   GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
   GPIO_InitStruct.Pull = GPIO_NOPULL;
   HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
 
-  /*Configure GPIO pins : PB0 PB1 PB2 PB10
+  /*Configure GPIO pins : PB0 PB1 PB2 PB3
-                           PB11 PB3 PB4 PB5
+                           PB4 PB5 PB6 PB7
-                           PB6 PB7 PB8 PB9 */
+                           PB8 PB9 */
-  GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_10
+  GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3
-                          |GPIO_PIN_11|GPIO_PIN_3|GPIO_PIN_4|GPIO_PIN_5
+                          |GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7
-                          |GPIO_PIN_6|GPIO_PIN_7|GPIO_PIN_8|GPIO_PIN_9;
+                          |GPIO_PIN_8|GPIO_PIN_9;
   GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
   GPIO_InitStruct.Pull = GPIO_NOPULL;
   HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
 
-  /*Configure GPIO pin : PtPin */
+  /*Configure GPIO pins : PBPin PBPin PBPin */
-  GPIO_InitStruct.Pin = SPI_CS_Pin;
+  GPIO_InitStruct.Pin = DisplayDC_Pin|DisplayReset_Pin|DisplayCS_Pin;
   GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
   GPIO_InitStruct.Pull = GPIO_NOPULL;
   GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
-  HAL_GPIO_Init(SPI_CS_GPIO_Port, &GPIO_InitStruct);
+  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
 
   /*Configure GPIO pin : PD2 */
   GPIO_InitStruct.Pin = GPIO_PIN_2;

cubemx/voc-sensor.ioc

@@ -22,9 +22,12 @@ Dma.SPI2_TX.1.Priority=DMA_PRIORITY_LOW
 Dma.SPI2_TX.1.RequestParameters=Instance,Direction,PeriphInc,MemInc,PeriphDataAlignment,MemDataAlignment,Mode,Priority
 FREERTOS.FootprintOK=true
 FREERTOS.HEAP_NUMBER=1
-FREERTOS.IPParameters=Tasks01,configCHECK_FOR_STACK_OVERFLOW,FootprintOK,HEAP_NUMBER
+FREERTOS.IPParameters=Tasks01,configCHECK_FOR_STACK_OVERFLOW,FootprintOK,HEAP_NUMBER,configRECORD_STACK_HIGH_ADDRESS,configUSE_MALLOC_FAILED_HOOK,configTOTAL_HEAP_SIZE
 FREERTOS.Tasks01=defaultTask,24,128,StartDefaultTask,Default,NULL,Dynamic,NULL,NULL;sensor,24,512,sensorTask,As external,NULL,Dynamic,NULL,NULL
 FREERTOS.configCHECK_FOR_STACK_OVERFLOW=2
+FREERTOS.configRECORD_STACK_HIGH_ADDRESS=1
+FREERTOS.configTOTAL_HEAP_SIZE=6000
+FREERTOS.configUSE_MALLOC_FAILED_HOOK=1
 File.Version=6
 GPIO.groupedBy=
 KeepUserPlacement=false
@@ -38,15 +41,18 @@ Mcu.IP5=SYS
 Mcu.IPNb=6
 Mcu.Name=STM32L152RCTx
 Mcu.Package=LQFP64
-Mcu.Pin0=PB12
+Mcu.Pin0=PA0-WKUP1
-Mcu.Pin1=PB13
+Mcu.Pin1=PB10
-Mcu.Pin2=PB14
+Mcu.Pin10=VP_SYS_VS_tim2
-Mcu.Pin3=PB15
+Mcu.Pin2=PB11
-Mcu.Pin4=PA13
+Mcu.Pin3=PB12
-Mcu.Pin5=PA14
+Mcu.Pin4=PB13
-Mcu.Pin6=VP_FREERTOS_VS_CMSIS_V2
+Mcu.Pin5=PB14
-Mcu.Pin7=VP_SYS_VS_tim2
+Mcu.Pin6=PB15
-Mcu.PinsNb=8
+Mcu.Pin7=PA13
+Mcu.Pin8=PA14
+Mcu.Pin9=VP_FREERTOS_VS_CMSIS_V2
+Mcu.PinsNb=11
 Mcu.ThirdPartyNb=0
 Mcu.UserConstants=
 Mcu.UserName=STM32L152RCTx
@@ -71,13 +77,21 @@ NVIC.TIM2_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:true
 NVIC.TimeBase=TIM2_IRQn
 NVIC.TimeBaseIP=TIM2
 NVIC.UsageFault_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false
+PA0-WKUP1.GPIOParameters=GPIO_Label
+PA0-WKUP1.GPIO_Label=VocSensorCS
+PA0-WKUP1.Signal=GPIO_Output
 PA13.Mode=Serial_Wire
 PA13.Signal=SYS_JTMS-SWDIO
 PA14.Mode=Serial_Wire
 PA14.Signal=SYS_JTCK-SWCLK
+PB10.GPIOParameters=GPIO_Label
+PB10.GPIO_Label=DisplayDC
+PB10.Signal=GPIO_Output
+PB11.GPIOParameters=GPIO_Label
+PB11.GPIO_Label=DisplayReset
+PB11.Signal=GPIO_Output
 PB12.GPIOParameters=GPIO_Label
-PB12.GPIO_Label=SPI_CS
+PB12.GPIO_Label=DisplayCS
-PB12.Locked=true
 PB12.Signal=GPIO_Output
 PB13.Mode=Full_Duplex_Master
 PB13.Signal=SPI2_SCK

src/SSD1306_SPI.hpp

@@ -0,0 +1,88 @@
+#pragma once
+
+#include "main.h"
+#include "semphr.h"
+#include "spi.h"
+
+#include "oled-driver/SSD1306Interface.hpp"
+
+constexpr size_t OledWidth = 128;
+constexpr size_t OledPages = 4;
+
+namespace
+{
+constexpr auto DisplaySpiPeripherie = &hspi2;
+} // namespace
+
+extern QueueHandle_t spiMutex;
+extern void waitForSpiFinished();
+
+//--------------------------------------------------------------------------------------------------
+//! SPI interface to a SSD1305/6 display controller.
+class SSD1306_SPI : public SSD1306Interface
+{
+public:
+    void writeCommand(uint8_t cmd) override
+    {
+        xSemaphoreTake(spiMutex, portMAX_DELAY);
+
+        setCommandPin();
+        setChipSelect(true);
+        HAL_SPI_Transmit_DMA(DisplaySpiPeripherie, &cmd, 1);
+        waitForSpiFinished();
+        setChipSelect(false);
+
+        xSemaphoreGive(spiMutex);
+    }
+
+    //--------------------------------------------------------------------------------------------------
+    void writeData(uint8_t data) override
+    {
+        xSemaphoreTake(spiMutex, portMAX_DELAY);
+
+        setDataPin();
+        setChipSelect(true);
+        HAL_SPI_Transmit_DMA(DisplaySpiPeripherie, &data, 1);
+        waitForSpiFinished();
+        setChipSelect(false);
+
+        xSemaphoreGive(spiMutex);
+    }
+
+    //--------------------------------------------------------------------------------------------------
+    void writeData(const uint8_t *data, unsigned int length) override
+    {
+        if (length > OledWidth * OledPages)
+            return;
+
+        xSemaphoreTake(spiMutex, portMAX_DELAY);
+
+        setDataPin();
+        setChipSelect(true);
+        HAL_SPI_Transmit_DMA(DisplaySpiPeripherie, const_cast<uint8_t *>(data), length);
+        waitForSpiFinished();
+        setChipSelect(false);
+
+        xSemaphoreGive(spiMutex);
+    }
+
+    //--------------------------------------------------------------------------------------------------
+private:
+    void setDataPin()
+    {
+        HAL_GPIO_WritePin(DisplayDC_GPIO_Port, DisplayDC_Pin, GPIO_PIN_SET);
+    }
+
+    //--------------------------------------------------------------------------------------------------
+    void setCommandPin()
+    {
+        HAL_GPIO_WritePin(DisplayDC_GPIO_Port, DisplayDC_Pin, GPIO_PIN_RESET);
+    }
+
+    //--------------------------------------------------------------------------------------------------
+    void setChipSelect(bool state)
+    {
+        HAL_GPIO_WritePin(DisplayCS_GPIO_Port, DisplayCS_Pin,
+                          state ? GPIO_PIN_RESET : GPIO_PIN_SET);
+    }
+};

src/bmeSPI.cxx

@@ -1,11 +1,21 @@
 #include "FreeRTOS.h"
 #include "gpio.h"
 #include "main.h"
+#include "semphr.h"
 #include "spi.h"
 #include "task.h"
+
 #include <cstring>
 
 #include "BME68x-Sensor-API/bme68x.h"
+#include "oled-driver/Renderer.hpp"
+
+extern QueueHandle_t spiMutex;
+extern void waitForSpiFinished();
+extern Renderer renderer;
+
+constexpr auto MaximumChars = 22 * 4;
+char buffer[MaximumChars];
 
 constexpr auto SPI_DEVICE = &hspi2;
 uint8_t txBuffer[512];
@@ -29,17 +39,15 @@ uint16_t dur_prof[10] = {100, 100, 100, 100, 100, 100, 100, 100, 100, 100};
 
 void setChipSelect(bool state)
 {
-    HAL_GPIO_WritePin(SPI_CS_GPIO_Port, SPI_CS_Pin, state ? GPIO_PIN_RESET : GPIO_PIN_SET);
+    HAL_GPIO_WritePin(VocSensorCS_GPIO_Port, VocSensorCS_Pin,
-}
+                      state ? GPIO_PIN_RESET : GPIO_PIN_SET);
-
-void waitForSpiFinished()
-{
-    ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
 }
 
 // SPI read function map
 BME68X_INTF_RET_TYPE bme68x_spi_read(uint8_t reg_addr, uint8_t *reg_data, uint32_t len, void *)
 {
+    xSemaphoreTake(spiMutex, portMAX_DELAY);
+
     setChipSelect(true);
     HAL_SPI_Transmit_DMA(SPI_DEVICE, &reg_addr, 1);
     waitForSpiFinished();
@@ -47,6 +55,8 @@ BME68X_INTF_RET_TYPE bme68x_spi_read(uint8_t reg_addr, uint8_t *reg_data, uint32
     waitForSpiFinished();
     setChipSelect(false);
 
+    xSemaphoreGive(spiMutex);
+
     return 0;
 }
 
@@ -60,11 +70,15 @@ BME68X_INTF_RET_TYPE bme68x_spi_write(uint8_t reg_addr, const uint8_t *reg_data,
     txBuffer[0] = reg_addr;
     std::memcpy(&txBuffer[1], reg_data, len);
 
+    xSemaphoreTake(spiMutex, portMAX_DELAY);
+
     setChipSelect(true);
     HAL_SPI_Transmit_DMA(SPI_DEVICE, const_cast<uint8_t *>(txBuffer), len + 1);
     waitForSpiFinished();
     setChipSelect(false);
 
+    xSemaphoreGive(spiMutex);
+
     return 0;
 }
 
@@ -153,10 +167,33 @@ void bmeRun()
         /* Check if res == BME68X_OK, report or handle if otherwise */
         for (uint8_t i = 0; i < n_fields; i++)
         {
-            // printf("%u, %u, %d, %u, %u, %u, 0x%x, %d, %d\n", sampleCount,
+            renderer.clearAll();
-            // time_ms,(bmeData[i].temperature / 100), bmeData[i].pressure, (bmeData[i].humidity /
+
-            // 1000),bmeData[i].gas_resistance,
+            snprintf(buffer, MaximumChars,
-            // bmeData[i].status,data[i].gas_index,data[i].meas_index);
+                     "%d°C, %luhPa, %lu%%\n%lukOhm, status: 0x%x\ngas_index: %d\nmeas_index: %d",
+                     bmeData[i].temperature / 100,     //
+                     bmeData[i].pressure / 100,        //
+                     bmeData[i].humidity / 1000,       //
+                     bmeData[i].gas_resistance / 1000, //
+                     bmeData[i].status,                //
+                     bmeData[i].gas_index,             //
+                     bmeData[i].meas_index);
+
+            renderer.print({0, 0}, buffer);
+            renderer.render();
+            /*
+            snprintf(buffer, MaximumChars, "sampleCount: %u\n, time_ms: %u\n \
+                     temperature; %d°C\n \
+                     pressure: %u\n \
+                     humidity: %u\n \
+                     gas_resistance: %u\n \
+                     // status: 0x%x\n \
+                     //gas_index: %d\n \
+                     meas_index: %d\n",
+                     sampleCount, time_ms, (bmeData[i].temperature / 100), bmeData[i].pressure,
+                     (bmeData[i].humidity / 1000), bmeData[i].gas_resistance, bmeData[i].status,
+                     bmeData[i].gas_index, bmeData[i].meas_index);
+            */
         }
     }
 

src/handlers.cxx

@@ -37,11 +37,15 @@ extern "C" void prvGetRegistersFromStack(uint32_t *pulFaultStackAddress)
     (void)pc;
     (void)psr;
 
-    /* When the following line is hit, the variables contain the register values. */
+/* When the following line is hit, the variables contain the register values. */
-    // HAL_GPIO_WritePin(LED_RED_GPIO_Port, LED_RED_Pin, GPIO_PIN_SET);
+// HAL_GPIO_WritePin(LED_RED_GPIO_Port, LED_RED_Pin, GPIO_PIN_SET);
+#ifdef DEBUG
+    __asm("bkpt");
+#else
     while (1)
     {
     }
+#endif
 }
 
 extern "C" void hard_fault_handler(void)
@@ -67,10 +71,13 @@ extern "C" void hard_fault_handler(void)
 
 extern "C" void vApplicationMallocFailedHook(void)
 {
-    // HAL_GPIO_WritePin(LED_RED_GPIO_Port, LED_RED_Pin, GPIO_PIN_SET);
+#ifdef DEBUG
+    __asm("bkpt");
+#else
     while (1)
     {
     }
+#endif
 }
 
 extern "C" void vApplicationStackOverflowHook(xTaskHandle *pxTask, signed portCHAR *pcTaskName)
@@ -78,8 +85,11 @@ extern "C" void vApplicationStackOverflowHook(xTaskHandle *pxTask, signed portCH
     (void)pxTask;
     (void)pcTaskName;
 
-    // HAL_GPIO_WritePin(LED_RED_GPIO_Port, LED_RED_Pin, GPIO_PIN_SET);
+#ifdef DEBUG
+    __asm("bkpt");
+#else
     while (1)
     {
     }
+#endif
 }

src/main.cxx

@@ -1,33 +1,79 @@
 #include "main.h"
 #include "FreeRTOS.h"
+#include "semphr.h"
 #include "task.h"
 
+#include "SSD1306_SPI.hpp"
+#include "oled-driver/Display.hpp"
+#include "oled-driver/Renderer.hpp"
+
 extern TaskHandle_t sensorHandle;
 extern void bmeRun();
 
+// oled display
+SSD1306_SPI ssdSpiInterface;
+Display display(ssdSpiInterface);
+Renderer renderer(128, 4, display);
+
+QueueHandle_t spiMutex = xSemaphoreCreateMutex();
+QueueHandle_t spiBinary = xSemaphoreCreateBinary();
+
 //--------------------------------------------------------------------------------------------------
-void notifySensorTask()
+void initDisplay()
+{
+    HAL_GPIO_WritePin(DisplayReset_GPIO_Port, DisplayReset_Pin, GPIO_PIN_RESET);
+    vTaskDelay(pdMS_TO_TICKS(1));
+    HAL_GPIO_WritePin(DisplayReset_GPIO_Port, DisplayReset_Pin, GPIO_PIN_SET);
+    vTaskDelay(pdMS_TO_TICKS(1));
+
+    display.setDisplayState(Display::DisplayState::Off);
+    display.setMultiplexRatio(OledPages * 8 - 1);
+    display.setComPinConfig(false, false);
+    display.setContrastControl(0xFF);
+    display.setDisplayClockDivide(0, 0x8);
+    display.setSegmentRemap(true);
+    display.setComOutputMode(Display::ComMode::Remap);
+    display.setPrechargingPeriod(1, 0xF);
+    display.setChargePump(true);
+
+    display.setMemoryAddressingMode(Display::AddressingMode::Horizontal);
+    display.setPageAddress(0, OledPages - 1);   // pages from 0 to 3
+    display.setColumnAddress(0, OledWidth - 1); // columns from 0 to 127
+
+    display.setDisplayState(Display::DisplayState::On);
+}
+
+//--------------------------------------------------------------------------------------------------
+void notifySpiIsFinished()
 {
     auto higherPriorityTaskWoken = pdFALSE;
-    vTaskNotifyGiveFromISR(sensorHandle, &higherPriorityTaskWoken);
+    xSemaphoreGiveFromISR(spiBinary, &higherPriorityTaskWoken);
     portYIELD_FROM_ISR(higherPriorityTaskWoken);
 }
 
+//--------------------------------------------------------------------------------------------------
+void waitForSpiFinished()
+{
+    xSemaphoreTake(spiBinary, portMAX_DELAY);
+}
+
 //--------------------------------------------------------------------------------------------------
 extern "C" void HAL_SPI_TxCpltCallback(SPI_HandleTypeDef *)
 {
-    notifySensorTask();
+    notifySpiIsFinished();
 }
 
 //--------------------------------------------------------------------------------------------------
 extern "C" void HAL_SPI_RxCpltCallback(SPI_HandleTypeDef *)
 {
-    notifySensorTask();
+    notifySpiIsFinished();
 }
 
 //--------------------------------------------------------------------------------------------------
 extern "C" void sensorTask(void *)
 {
+    initDisplay();
+
     bmeRun();
     while (1)
     {

src/oled-driver

@@ -0,0 +1 @@
+Subproject commit a224095e81a4728faa1311f0d717eb54959c6430