/* * This file is part of the libopencm3 project. * * Copyright (C) 2010 Thomas Otto * Copyright (C) 2012 Piotr Esden-Tempski * Copyright (C) 2012 Stephen Dwyer * * This library is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library. If not, see . */ #include #include #include #include #include #include #include volatile u16 temperature = 0; void usart_setup(void) { /* Enable clocks for GPIO port A (for GPIO_USART1_TX) and USART1. */ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN); rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN); /* Setup GPIO pin GPIO_USART1_TX/GPIO9 on GPIO port A for transmit. */ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX); /* Setup UART parameters. */ usart_set_baudrate(USART2, 115200); usart_set_databits(USART2, 8); usart_set_stopbits(USART2, USART_STOPBITS_1); usart_set_mode(USART2, USART_MODE_TX_RX); usart_set_parity(USART2, USART_PARITY_NONE); usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE); /* Finally enable the USART. */ usart_enable(USART2); } void gpio_setup(void) { /* Enable GPIO clocks. */ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN); rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPCEN); /* Setup the LEDs. */ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO8); gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO15); } void timer_setup(void) { /* Set up the timer TIM2 for injected sampling */ uint32_t timer; volatile uint32_t *rcc_apbenr; uint32_t rcc_apb; timer = TIM2; rcc_apbenr = &RCC_APB1ENR; rcc_apb = RCC_APB1ENR_TIM2EN; rcc_peripheral_enable_clock(rcc_apbenr, rcc_apb); /* Time Base configuration */ timer_reset(timer); timer_set_mode(timer, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP); timer_set_period(timer, 0xFF); timer_set_prescaler(timer, 0x8); timer_set_clock_division(timer, 0x0); /* Generate TRGO on every update. */ timer_set_master_mode(timer, TIM_CR2_MMS_UPDATE); timer_enable_counter(timer); } void irq_setup(void) { /* Enable the adc1_2_isr() routine */ nvic_set_priority(NVIC_ADC1_2_IRQ, 0); nvic_enable_irq(NVIC_ADC1_2_IRQ); } void adc_setup(void) { int i; rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_ADC1EN); /* Make sure the ADC doesn't run during config. */ adc_off(ADC1); /* We configure everything for one single timer triggered injected conversion with interrupt generation. */ /* While not needed for a single channel, try out scan mode which does all channels in one sweep and * generates the interrupt/EOC/JEOC flags set at the end of all channels, not each one. */ adc_enable_scan_mode(ADC1); adc_set_single_conversion_mode(ADC1); /* We want to start the injected conversion with the TIM2 TRGO */ adc_enable_external_trigger_injected(ADC1,ADC_CR2_JEXTSEL_TIM2_TRGO); /* Generate the ADC1_2_IRQ */ adc_enable_jeoc_interrupt(ADC1); adc_set_right_aligned(ADC1); /* We want to read the temperature sensor, so we have to enable it. */ adc_enable_temperature_sensor(ADC1); adc_set_conversion_time_on_all_channels(ADC1, ADC_SMPR_SMP_28DOT5CYC); adc_on(ADC1); /* Wait for ADC starting up. */ for (i = 0; i < 800000; i++) /* Wait a bit. */ __asm__("nop"); adc_reset_calibration(ADC1); while ((ADC_CR2(ADC1) & ADC_CR2_RSTCAL) != 0); adc_calibration(ADC1); while ((ADC_CR2(ADC1) & ADC_CR2_CAL) != 0); } void my_usart_print_int(u32 usart, int value) { s8 i; u8 nr_digits = 0; char buffer[25]; if (value < 0) { usart_send_blocking(usart, '-'); value = value * -1; } while (value > 0) { buffer[nr_digits++] = "0123456789"[value % 10]; value /= 10; } for (i = (nr_digits - 1); i >= 0; i--) { usart_send_blocking(usart, buffer[i]); } usart_send_blocking(usart, '\r'); } int main(void) { u8 channel_array[16]; rcc_clock_setup_in_hse_12mhz_out_72mhz(); gpio_setup(); usart_setup(); timer_setup(); irq_setup(); adc_setup(); gpio_set(GPIOA, GPIO8); /* LED1 on */ gpio_set(GPIOC, GPIO15); /* LED2 on */ /* Send a message on USART1. */ usart_send_blocking(USART2, 's'); usart_send_blocking(USART2, 't'); usart_send_blocking(USART2, 'm'); usart_send_blocking(USART2, '\r'); usart_send_blocking(USART2, '\n'); /* Select the channel we want to convert. 16=temperature_sensor. */ channel_array[0] = 16; /* Set the injected sequence here, with number of channels */ adc_set_injected_sequence(ADC1, 1, channel_array); /* Continously convert and poll the temperature ADC. */ while (1) { /* * Since sampling is triggered by the timer and copying the value * out of the data register is handled by the interrupt routine, * we just need to print the value and toggle the LED. It may be useful * to buffer the adc values in some cases. */ /* * That's actually not the real temperature - you have to compute it * as described in the datasheet. */ my_usart_print_int(USART2, temperature); gpio_toggle(GPIOA, GPIO8); /* LED2 on */ } return 0; } void adc1_2_isr(void) { /* Clear Injected End Of Conversion (JEOC) */ ADC_SR(ADC1) &= ~ADC_SR_JEOC; temperature = ADC_JDR1(ADC1); }