From dcd98dde86c68340e950d12b078d24fd30bef625 Mon Sep 17 00:00:00 2001 From: Piotr Esden-Tempski Date: Tue, 28 Aug 2012 15:56:29 -0700 Subject: Renamed adc example to be more descriptive. --- examples/stm32/f1/lisa-m-2/adc_regular/adc.c | 162 +++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100644 examples/stm32/f1/lisa-m-2/adc_regular/adc.c (limited to 'examples/stm32/f1/lisa-m-2/adc_regular/adc.c') diff --git a/examples/stm32/f1/lisa-m-2/adc_regular/adc.c b/examples/stm32/f1/lisa-m-2/adc_regular/adc.c new file mode 100644 index 0000000..91d029f --- /dev/null +++ b/examples/stm32/f1/lisa-m-2/adc_regular/adc.c @@ -0,0 +1,162 @@ +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2010 Thomas Otto + * Copyright (C) 2012 Piotr Esden-Tempski + * + * 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 + +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 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 conversion. */ + adc_disable_scan_mode(ADC1); + adc_set_single_conversion_mode(ADC1); + adc_enable_discontinous_mode_regular(ADC1); + adc_disable_external_trigger_regular(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); + adc_calibration(ADC1); +} + +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; i >= 0; i--) { + usart_send_blocking(usart, buffer[i]); + } + + usart_send_blocking(usart, '\r'); +} + +int main(void) +{ + u8 channel_array[16]; + u16 temperature = 0; + + rcc_clock_setup_in_hse_12mhz_out_72mhz(); + gpio_setup(); + usart_setup(); + adc_setup(); + + gpio_set(GPIOA, GPIO8); /* LED1 on */ + gpio_set(GPIOC, GPIO15); /* LED2 off */ + + /* 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; + adc_set_regular_sequence(ADC1, 1, channel_array); + + /* Continously convert and poll the temperature ADC. */ + while (1) { + /* + * If the ADC_CR2_ON bit is already set -> setting it another time + * starts the conversion. + */ + adc_on(ADC1); + + /* Wait for end of conversion. */ + while (!(ADC_SR(ADC1) & ADC_SR_EOC)); + + temperature = ADC_DR(ADC1); + + /* + * 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; +} -- cgit v1.2.3