Arduino for STM32

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#include <SoftwareSerial.h>
#include <Arduino.h>
#include <HardwareTimer.h>

#include "stm32l4xx.h"
#include "stm32l4xx_hal.h"
#include "stm32l4xx_hal_def.h"
#include "stm32l4xx_hal_gpio.h"
#include "stm32l4xx_hal_sai.h"
#include "stm32l4xx_hal_exti.h"
#include "stm32l4xx_hal_cortex.h"

#include "Sysclock_Config.h"

void assert_failed(uint8_t* inFileName, uint32_t line) {
	char* fileNameAsString = (char*)inFileName;
	Serial2.println(F("*** [HAL ASSERT FAILED] ***"));
	Serial2.printf("%s\r\n", (char*)inFileName);
	Serial2.printf("%i\r\n", line);
}
void _Error_Handler(const char* file, int line) {
	Serial2.println(F("*** [ERROR HANDLED] ***"));
	Serial2.printf("%s\r\n", file);
	Serial2.printf("%i\r\n", line);
}


GPIO_InitTypeDef gpioInit;
SAI_HandleTypeDef saiHandle;
RCC_PeriphCLKInitTypeDef periphInit;
uint8_t	SAIDataBuffer[8] = { 0 };

HardwareTimer sampleTimer(TIM3);

void samplerCallback();

// the setup function runs once when you press reset or power the board
void setup() {
	delay(5000);

	Serial2.begin(115200);
	Serial2.println("Starting");

		/*
			Enable the GPIO B clock.
		*/
	__HAL_RCC_GPIOB_CLK_ENABLE();


	/*
		Enable the peripheral clock.
	*/

	__HAL_RCC_SAI1_CLK_ENABLE();


	/*
		Configure the GPIO pins.
	*/
	/**
	SAI1_A_Block_A GPIO Configuration
	PB15     ------> SAI1_SD_A
	PB10     ------> SAI1_SCK_A
	PB12     ------> SAI1_FS_A
	*/
	gpioInit.Pin = GPIO_PIN_15 | GPIO_PIN_10 | GPIO_PIN_12;
	gpioInit.Mode = GPIO_MODE_AF_PP;
	gpioInit.Pull = GPIO_NOPULL;
	gpioInit.Speed = GPIO_SPEED_FREQ_LOW;
	gpioInit.Alternate = GPIO_AF13_SAI1;
	HAL_GPIO_Init(GPIOB, &gpioInit);


	pinMode(PB1, OUTPUT);
	digitalWrite(PB1, LOW);


	__HAL_SAI_DISABLE(&saiHandle);

	// Block type def.
	saiHandle.Instance = SAI1_Block_A; // audio block A.

	saiHandle.Init.Protocol = SAI_FREE_PROTOCOL;
	saiHandle.Init.FirstBit = SAI_FIRSTBIT_MSB;
	saiHandle.Init.AudioFrequency = SAI_AUDIO_FREQUENCY_44K;
	saiHandle.Init.AudioMode = SAI_MODEMASTER_RX; // block a must provide clock signals and receive from the data line.
	saiHandle.Init.Synchro = SAI_ASYNCHRONOUS;	// we only want to use this one audio block.
	saiHandle.Init.SynchroExt = SAI_SYNCEXT_DISABLE; // disable sychronizing the 2 audio blocks.
	saiHandle.Init.OutputDrive = SAI_OUTPUTDRIVE_DISABLE; // assume to power the data?
	saiHandle.Init.NoDivider = SAI_MASTERDIVIDER_ENABLE; // any frame length allowed.
	saiHandle.Init.FIFOThreshold = SAI_FIFOTHRESHOLD_EMPTY;	// used for interrupts.
	saiHandle.Init.MonoStereoMode = SAI_STEREOMODE; // mono mode only available in transmission mode.
	saiHandle.Init.CompandingMode = SAI_NOCOMPANDING; // telecommunications specification (not needed)
	saiHandle.Init.TriState = SAI_OUTPUT_NOTRELEASED; // assume the SAI is ma

	//saiHandle.Init.ClockStrobing = SAI_CLOCKSTROBING_FALLINGEDGE;
	//saiHandle.Init.DataSize = SAI_DATASIZE_32;

	// block frame parameters.
	saiHandle.FrameInit.FrameLength = 64; // 64 bit frame. (2 slots)
	saiHandle.FrameInit.ActiveFrameLength = 32; // Frame synchronization active level length. (half the frame length)
	saiHandle.FrameInit.FSDefinition = SAI_FS_CHANNEL_IDENTIFICATION;
	saiHandle.FrameInit.FSPolarity = SAI_FS_ACTIVE_LOW;
	saiHandle.FrameInit.FSOffset = SAI_FS_BEFOREFIRSTBIT;

	// block slot parameters.
	saiHandle.SlotInit.FirstBitOffset = 0; // no offset in receive mode -> FBOFF <= (SLOTSZ - DS)
	saiHandle.SlotInit.SlotSize = SAI_SLOTSIZE_32B; // 32 bits per slot to contain the 32 data bits (24 data, 8 zeroed)
	saiHandle.SlotInit.SlotNumber = 2;
	saiHandle.SlotInit.SlotActive = SAI_SLOTACTIVE_ALL;

	/*
			https://www.keil.com/pack/doc/CMSIS/Driver/html/group__sai__interface__gr.html
	*/
	HAL_StatusTypeDef saiStatus = HAL_SAI_InitProtocol(&saiHandle,
		SAI_I2S_STANDARD, // runs the SAI_InitI2S() function.
		SAI_PROTOCOL_DATASIZE_24BIT,// 24 bits (24 bit is standard for I2S).
		2);			 // number of slots per frame - 1

	__HAL_SAI_ENABLE(&saiHandle); // without this line of code the first read takes 84us because it settings sai enabled.

	if (saiStatus != HAL_OK)
	{
		Serial2.println("SAI ERROR");
		while (1) {}
	}


	sampleTimer.setMode(1, TIMER_OUTPUT_COMPARE, NC); // remove this for new version of STM32Dino, required version 1.8.0.
	sampleTimer.setOverflow(16000, HERTZ_FORMAT);
	sampleTimer.detachInterrupt();
	sampleTimer.attachInterrupt(samplerCallback);
	sampleTimer.resume();
}

long elapsed = 0;

void samplerCallback()
{

	long stamp = micros();

	HAL_StatusTypeDef rxResponse;

	/*
	* Perform sampling
	*/
	rxResponse = HAL_SAI_Receive(&saiHandle, SAIDataBuffer, 2U, 10000);

	if (rxResponse != HAL_OK)
	{
		Serial2.println("Error in SAI");
		while (1) { }
	}

	elapsed = micros() - stamp;
}

void signalWatchdog()
{
	// do signal watchdog (placeholder)
}

void loop() {
	signalWatchdog();
	Serial2.println(elapsed);
}

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void loop() {
	signalWatchdog(); // this is never called
	Serial2.println(elapsed);
}