/* Example for the STM32L031 Eval Board with 128x64 OLED at PA13/PA14 */ #include #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; // u8x8 object uint8_t u8x8_x, u8x8_y; // current position on the screen 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) ; SystemCoreClockUpdate(); /* Update SystemCoreClock global variable */ } /* Enable several power regions: PWR, GPIOA 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) */ PWR->CR |= PWR_CR_DBP; /* activate write access to RCC->CSR and RTC */ SysTick->LOAD = (SystemCoreClock/1000)*50 - 1; /* 50ms task */ SysTick->VAL = 0; SysTick->CTRL = 7; /* enable, generate interrupt (SysTick_Handler), do not divide by 2 */ } /*=======================================================================*/ /* u8x8 display procedures */ void initDisplay(void) { 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_x = 0; u8x8_y = 0; } void outChar(uint8_t c) { if ( u8x8_x >= u8x8_GetCols(&u8x8) ) { u8x8_x = 0; u8x8_y++; } u8x8_DrawGlyph(&u8x8, u8x8_x, u8x8_y, c); u8x8_x++; } void outStr(const char *s) { while( *s ) outChar(*s++); } void outHexHalfByte(uint8_t b) { b &= 0x0f; if ( b < 10 ) outChar(b+'0'); else outChar(b+'a'-10); } void outHex8(uint8_t b) { outHexHalfByte(b >> 4); outHexHalfByte(b); } void outHex16(uint16_t v) { outHex8(v>>8); outHex8(v); } void outHex32(uint32_t v) { outHex16(v>>16); outHex16(v); } void setRow(uint8_t r) { u8x8_x = 0; u8x8_y = r; } /*=======================================================================*/ void initADC(void) { //__disable_irq(); /* ADC Clock Enable */ RCC->APB2ENR |= RCC_APB2ENR_ADCEN; /* enable ADC clock */ __NOP(); /* let us wait for some time */ __NOP(); /* let us wait for some time */ /* ADC Reset */ 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 */ /* ADC Basic Setup */ 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 */ { /* is this correct, i think we must use the disable flag here */ 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 */ { } } /* ch0 PA0 pin 6 ch1 PA1 pin 7 ch2 PA2 pin 8 ch3 PA3 pin 9 ch4 PA4 pin 10 ch5 PA5 pin 11 ch6 PA6 pin 12 ch7 PA7 pin 13 ch8 PB0 - ch9 PB1 pin 14 ch 0..15: GPIO ch 16: ??? ch 17: vref (bandgap) ch18: temperature sensor returns 12 bit result, right aligned */ uint16_t getADC(uint8_t ch) { uint32_t data; uint32_t i; /* 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; return data; } /*=======================================================================*/ void main() { uint16_t adc_value; uint16_t i; setHSIClock(); /* enable 32 MHz Clock */ startUp(); /* enable systick irq and several power regions */ initDisplay(); /* aktivate display */ initADC(); RCC->IOPENR |= RCC_IOPENR_IOPAEN; /* Enable clock for GPIO Port A */ __NOP(); __NOP(); GPIOA->MODER &= ~GPIO_MODER_MODE1; /* clear mode for PA1 */ GPIOA->MODER |= GPIO_MODER_MODE1_0; /* Output mode for PA1 */ GPIOA->OTYPER &= ~GPIO_OTYPER_OT_1; /* no Push/Pull for PA1 */ GPIOA->OSPEEDR &= ~GPIO_OSPEEDER_OSPEED1; /* low speed for PA1 */ GPIOA->PUPDR &= ~GPIO_PUPDR_PUPD1; /* no pullup/pulldown for PA1 */ GPIOA->BSRR = GPIO_BSRR_BS_1; /* atomic set PA1 */ setRow(0); outStr("ADC Test"); setRow(2); outStr("ch5 pin11: "); setRow(3); outHex16(getADC(5)); setRow(4); outStr("bandgap: "); setRow(5); outHex16(getADC(17)); setRow(6); outStr("temp: "); setRow(7); outHex16(getADC(18)); for(;;) { for( i = 0; i < 2000; i++ ) { adc_value = getADC(5); GPIOA->BSRR = GPIO_BSRR_BR_1; /* atomic clr PA1 */ delay_system_ticks(0x1000 - adc_value); GPIOA->BSRR = GPIO_BSRR_BS_1; /* atomic set PA1 */ delay_system_ticks(adc_value); } setRow(3); outHex16(adc_value); } }