/* LED blink project for the STM32L031 */
#include "stm32l031xx.h"
#include "delay.h"
#include "u8x8.h"
/*=======================================================================*/
/* external functions */
uint8_t u8x8_gpio_and_delay_stm32l0(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr);
/*=======================================================================*/
/* global variables */
u8x8_t u8x8;
volatile unsigned long SysTickCount = 0;
/*=======================================================================*/
void __attribute__ ((interrupt, used)) SysTick_Handler(void)
{
SysTickCount++;
}
void setHSIClock()
{
/* test if the current clock source is something else than HSI */
if ((RCC->CFGR & RCC_CFGR_SWS) != RCC_CFGR_SWS_HSI)
{
/* enable HSI */
RCC->CR |= RCC_CR_HSION;
/* wait until HSI becomes ready */
while ( (RCC->CR & RCC_CR_HSIRDY) == 0 )
;
/* enable the HSI "divide by 4" bit */
RCC->CR |= (uint32_t)(RCC_CR_HSIDIVEN);
/* wait until the "divide by 4" flag is enabled */
while((RCC->CR & RCC_CR_HSIDIVF) == 0)
;
/* then use the HSI clock */
RCC->CFGR = (RCC->CFGR & (uint32_t) (~RCC_CFGR_SW)) | RCC_CFGR_SW_HSI;
/* wait until HSI clock is used */
while ((RCC->CFGR & RCC_CFGR_SWS) != RCC_CFGR_SWS_HSI)
;
}
/* disable PLL */
RCC->CR &= (uint32_t)(~RCC_CR_PLLON);
/* wait until PLL is inactive */
while((RCC->CR & RCC_CR_PLLRDY) != 0)
;
/* set latency to 1 wait state */
FLASH->ACR |= FLASH_ACR_LATENCY;
/* At this point the HSI runs with 4 MHz */
/* Multiply by 16 device by 2 --> 32 MHz */
RCC->CFGR = (RCC->CFGR & (~(RCC_CFGR_PLLMUL| RCC_CFGR_PLLDIV ))) | (RCC_CFGR_PLLMUL16 | RCC_CFGR_PLLDIV2);
/* enable PLL */
RCC->CR |= RCC_CR_PLLON;
/* wait until the PLL is ready */
while ((RCC->CR & RCC_CR_PLLRDY) == 0)
;
/* use the PLL has clock source */
RCC->CFGR |= (uint32_t) (RCC_CFGR_SW_PLL);
/* wait until the PLL source is active */
while ((RCC->CFGR & RCC_CFGR_SWS) != RCC_CFGR_SWS_PLL)
;
}
/*
Enable several power regions: PWR, GPIOA
Enable write access to RTC
This must be executed after each reset.
*/
void startUp(void)
{
RCC->IOPENR |= RCC_IOPENR_IOPAEN; /* Enable clock for GPIO Port A */
RCC->APB1ENR |= RCC_APB1ENR_PWREN; /* enable power interface */
PWR->CR |= PWR_CR_DBP; /* activate write access to RCC->CSR and RTC */
//PWR_CSR_Backup = PWR->CSR; /* create a backup of the original PWR_CSR register for later analysis */
PWR->CR |= PWR_CR_CSBF; /* clear the standby flag in the PWR_CSR register, but luckily we have a copy */
PWR->CR |= PWR_CR_CWUF; /* also clear the WUF flag in PWR_CSR */
/* PA0, TAMP2, button input */
GPIOA->MODER &= ~GPIO_MODER_MODE0; /* clear mode for PA0 */
GPIOA->PUPDR &= ~GPIO_PUPDR_PUPD0; /* no pullup/pulldown for PA0 */
GPIOA->PUPDR |= GPIO_PUPDR_PUPD0_0; /* pullup for PA0 */
/* PA2, TAMP3, button input */
GPIOA->MODER &= ~GPIO_MODER_MODE2; /* clear mode for PA2 */
GPIOA->PUPDR &= ~GPIO_PUPDR_PUPD2; /* no pullup/pulldown for PA2 */
GPIOA->PUPDR |= GPIO_PUPDR_PUPD2_0; /* pullup for PA2 */
}
/* write access must be activated before calling this function: PWR->CR |= PWR_CR_DBP; */
unsigned int initRTC(void)
{
unsigned int r = 0;
/* real time clock enable */
//enableRCCRTCWrite();
__disable_irq();
RTC->WPR = 0x0ca; /* disable RTC write protection */
RTC->WPR = 0x053;
/* try externel 32K clock source */
RCC->CSR |= RCC_CSR_LSEBYP; /* bypass oscillator */
RCC->CSR |= RCC_CSR_LSEON; /* enable low speed external clock */
delay_micro_seconds(100000*5); /* LSE requires between 100ms to 200ms */
if ( RCC->CSR & RCC_CSR_LSERDY )
{
r = 1;
}
else
{
RCC->CSR &= ~RCC_CSR_LSEON; /* disable external clock */
/* try externel 32K oscillator */
RCC->CSR &= ~RCC_CSR_LSEBYP; /* no bypass oscillator */
RCC->CSR &= ~RCC_CSR_LSEDRV_Msk; /* lowest drive */
RCC->CSR |= RCC_CSR_LSEDRV_0; /* medium low drive */
RCC->CSR |= RCC_CSR_LSEON; /* enable low speed external clock */
delay_micro_seconds(100000*6); /* LSE requires between 200ms and 400ms */
if ( RCC->CSR & RCC_CSR_LSERDY )
{
r = 2;
}
}
if ( r > 0 )
{
RCC->CSR &= ~RCC_CSR_RTCSEL_Msk; /* no clock selection for RTC */
RCC->CSR |= RCC_CSR_RTCSEL_LSE; /* select LSE */
RCC->CSR |= RCC_CSR_RTCEN; /* enable RTC */
RTC->ISR = RTC_ISR_INIT; /* request RTC stop */
while((RTC->ISR & RTC_ISR_INITF)!=RTC_ISR_INITF) /* wait for stop */
;
RTC->PRER = 0x07f00ff; /* 1 Hz clock */
RTC->TR = 0;
RTC->ISR =~ RTC_ISR_INIT; /* start RTC */
}
RTC->WPR = 0; /* enable RTC write protection */
RTC->WPR = 0;
__enable_irq();
return r;
}
void printBits(uint8_t y, uint16_t val)
{
int i;
for( i = 0; i < 16; i++ )
{
u8x8_DrawGlyph(&u8x8, i, y, val & (1<<(15-i)) ? '1' : '0' );
}
}
/*
ch 0..15: GPIO
ch 16: ???
ch 17: vref (bandgap)
ch18: temperature sensor
returns 12 bit result, right aligned
*/
uint16_t readADC(uint8_t ch)
{
uint32_t data;
uint32_t i;
__disable_irq();
/* ADC RESET */
RCC->APB2ENR |= RCC_APB2ENR_ADCEN; /* enable ADC clock */
__NOP(); /* let us wait for some time */
__NOP(); /* let us wait for some time */
RCC->APB2RSTR |= RCC_APB2RSTR_ADCRST;
__NOP(); /* let us wait for some time */
__NOP(); /* let us wait for some time */
RCC->APB2RSTR &= ~RCC_APB2RSTR_ADCRST;
__NOP(); /* let us wait for some time */
__NOP(); /* let us wait for some time */
/* Enable some basic parts */
ADC1->IER = 0; /* do not allow any interrupts */
ADC1->CFGR2 &= ~ADC_CFGR2_CKMODE; /* select HSI16 clock */
ADC1->CR |= ADC_CR_ADVREGEN; /* enable ADC voltage regulator, probably not required, because this is automatically activated */
ADC->CCR |= ADC_CCR_VREFEN; /* Wake-up the VREFINT */
ADC->CCR |= ADC_CCR_TSEN; /* Wake-up the temperature sensor */
__NOP(); /* let us wait for some time */
__NOP(); /* let us wait for some time */
/* CALIBRATION */
if ((ADC1->CR & ADC_CR_ADEN) != 0) /* clear ADEN flag if required */
{
ADC1->CR &= (uint32_t)(~ADC_CR_ADEN);
}
ADC1->CR |= ADC_CR_ADCAL; /* start calibration */
while ((ADC1->ISR & ADC_ISR_EOCAL) == 0) /* wait for clibration finished */
{
}
ADC1->ISR |= ADC_ISR_EOCAL; /* clear the status flag, by writing 1 to it */
__NOP(); /* not sure why, but some nop's are required here, at least 4 of them */
__NOP();
__NOP();
__NOP();
__NOP();
__NOP();
/* ENABLE ADC */
ADC1->ISR |= ADC_ISR_ADRDY; /* clear ready flag */
ADC1->CR |= ADC_CR_ADEN; /* enable ADC */
while ((ADC1->ISR & ADC_ISR_ADRDY) == 0) /* wait for ADC */
{
}
//printBits(5, ADC1->ISR );
//printBits(6, ADC1->CR );
/* CONFIGURE ADC */
ADC1->CFGR1 &= ~ADC_CFGR1_EXTEN; /* software enabled conversion start */
ADC1->CFGR1 &= ~ADC_CFGR1_ALIGN; /* right alignment */
ADC1->CFGR1 &= ~ADC_CFGR1_RES; /* 12 bit resolution */
ADC1->CHSELR = 1<<ch; /* Select channel */
ADC1->SMPR |= ADC_SMPR_SMP_0 | ADC_SMPR_SMP_1 | ADC_SMPR_SMP_2; /* Select a sampling mode of 111 (very slow)*/
/* DO CONVERSION */
data = 0;
for( i = 0; i < 8; i++ )
{
ADC1->CR |= ADC_CR_ADSTART; /* start the ADC conversion */
while ((ADC1->ISR & ADC_ISR_EOC) == 0) /* wait end of conversion */
{
}
data += ADC1->DR; /* get ADC result and clear the ISR_EOC flag */
}
data >>= 3;
/* DISABLE ADC */
/* at this point the end of sampling and end of sequence bits are also set in ISR registr */
if ( (ADC1->CR & ADC_CR_ADEN) != 0 )
{
ADC1->CR |= ADC_CR_ADDIS; /* disable ADC... maybe better execute a reset */
while ((ADC1->CR & ADC_CR_ADEN) != 0) /* wait for ADC disable, ADEN is also cleared */
{
}
}
/* DISABLE OTHER PARTS, INCLUDING CLOCK */
ADC->CCR &= ~ADC_CCR_VREFEN; /* disable VREFINT */
ADC->CCR &= ~ADC_CCR_TSEN; /* disable temperature sensor */
ADC1->CR &= ~ADC_CR_ADVREGEN; /* disable ADC voltage regulator */
RCC->APB2ENR &= ~RCC_APB2ENR_ADCEN; /* disable ADC clock */
__enable_irq();
return data;
}
uint16_t getTemperature(void)
{
int16_t y1, y2,x1, x2, t;
int16_t y;
y1 = 30;
x1 = *(uint16_t *)(0x1FF8007A); // 30 degree with 3.0V
x1 *=30;
x1 /=33;
y2 = 110; // AN3964: 110 degree, Datasheet: 130 degree
x2 = *(uint16_t *)(0x1FF8007E); // 130 degree with 3.0V
x2 *=30;
x2 /=33;
t = readADC(18);
y = ( (y2 - y1) * ( t - x1) ) / (x2 - x1) + y1;
u8x8_DrawString(&u8x8, 0,6, u8x8_u16toa((y2 - y1)/(x2 - x1), 5));
u8x8_DrawString(&u8x8, 7,6, u8x8_u16toa(t, 5));
u8x8_DrawString(&u8x8, 13,6, u8x8_u16toa(y, 3));
return y;
}
int main()
{
unsigned int rtcState;
setHSIClock();
SystemCoreClockUpdate(); /* Update SystemCoreClock() */
//SystemCoreClock = 32000000UL;
RCC->IOPENR |= RCC_IOPENR_IOPAEN; /* Enable clock for GPIO Port A */
__NOP();
__NOP();
GPIOA->MODER &= ~GPIO_MODER_MODE13; /* clear mode for PA13 */
GPIOA->MODER |= GPIO_MODER_MODE13_0; /* Output mode for PA13 */
GPIOA->OTYPER &= ~GPIO_OTYPER_OT_13; /* Push/Pull for PA13 */
GPIOA->OSPEEDR &= ~GPIO_OSPEEDER_OSPEED13; /* low speed for PA13 */
GPIOA->PUPDR &= ~GPIO_PUPDR_PUPD13; /* no pullup/pulldown for PA13 */
GPIOA->BSRR = GPIO_BSRR_BR_13; /* atomic clr PA13 */
GPIOA->BSRR = GPIO_BSRR_BS_13; /* atomic set PA13 */
SysTick->LOAD = (SystemCoreClock/1000)*50 - 1; /* 50ms task */
SysTick->VAL = 0;
SysTick->CTRL = 7; /* enable, generate interrupt (SysTick_Handler), do not divide by 2 */
/* setup display */
//u8g2_Setup_ssd1306_i2c_128x64_noname_2(&u8g2, U8G2_R0, u8x8_byte_sw_i2c, u8x8_gpio_and_delay_stm32l0);
//u8g2_InitDisplay(&u8g2);
//u8g2_SetPowerSave(&u8g2, 0);
startUp();
rtcState = initRTC();
u8x8_Setup(&u8x8, u8x8_d_ssd1306_128x64_noname, u8x8_cad_ssd13xx_i2c, u8x8_byte_sw_i2c, u8x8_gpio_and_delay_stm32l0);
u8x8_InitDisplay(&u8x8);
u8x8_ClearDisplay(&u8x8);
u8x8_SetPowerSave(&u8x8, 0);
u8x8_SetFont(&u8x8, u8x8_font_amstrad_cpc_extended_r);
u8x8_DrawString(&u8x8, 0,0, "Hello World!");
u8x8_DrawGlyph(&u8x8, 0,1, rtcState+'0');
u8x8_DrawString(&u8x8, 0,2, "Vref:");
u8x8_DrawString(&u8x8, 7,2, u8x8_u16toa(readADC(17), 4));
u8x8_DrawString(&u8x8, 0,3, "Temp:");
u8x8_DrawString(&u8x8, 7,3, u8x8_u16toa(readADC(18), 4));
u8x8_DrawString(&u8x8, 13,3, u8x8_u16toa(getTemperature(), 3));
u8x8_DrawString(&u8x8, 0,4, "c30:");
u8x8_DrawString(&u8x8, 7,4, u8x8_u16toa(*(uint16_t *)(0x1FF8007A), 4));
u8x8_DrawString(&u8x8, 0,5, "c130:");
u8x8_DrawString(&u8x8, 7,5, u8x8_u16toa(*(uint16_t *)(0x1FF8007E), 4));
for(;;)
{
u8x8_DrawString(&u8x8, 0,2, "Vref:");
u8x8_DrawString(&u8x8, 7,2, u8x8_u16toa(readADC(17), 4));
u8x8_DrawString(&u8x8, 0,3, "Temp:");
u8x8_DrawString(&u8x8, 7,3, u8x8_u16toa(readADC(18), 4));
u8x8_DrawString(&u8x8, 13,3, u8x8_u16toa(getTemperature(), 3));
u8x8_DrawString(&u8x8, 0,4, "c30:");
u8x8_DrawString(&u8x8, 7,4, u8x8_u16toa(*(uint16_t *)(0x1FF8007A), 4));
u8x8_DrawString(&u8x8, 0,5, "c130:");
u8x8_DrawString(&u8x8, 7,5, u8x8_u16toa(*(uint16_t *)(0x1FF8007E), 4));
delay_micro_seconds(500000);
GPIOA->BSRR = GPIO_BSRR_BS_13; /* atomic set PA13 */
delay_micro_seconds(500000);
GPIOA->BSRR = GPIO_BSRR_BR_13; /* atomic clr PA13 */
}
}