/* 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<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 */ } }