From c5d6480201543c607664df4455e9337db305f0b6 Mon Sep 17 00:00:00 2001 From: Frantisek Burian Date: Sat, 14 Dec 2013 19:18:22 +0100 Subject: [PATCH] [EXAMPLE:F0] Add simple ADC example --- .../stm32/f0/stm32f0-discovery/adc/Makefile | 24 ++++ .../stm32/f0/stm32f0-discovery/adc/README | 11 ++ examples/stm32/f0/stm32f0-discovery/adc/adc.c | 131 ++++++++++++++++++ 3 files changed, 166 insertions(+) create mode 100644 examples/stm32/f0/stm32f0-discovery/adc/Makefile create mode 100644 examples/stm32/f0/stm32f0-discovery/adc/README create mode 100644 examples/stm32/f0/stm32f0-discovery/adc/adc.c diff --git a/examples/stm32/f0/stm32f0-discovery/adc/Makefile b/examples/stm32/f0/stm32f0-discovery/adc/Makefile new file mode 100644 index 0000000..2730d18 --- /dev/null +++ b/examples/stm32/f0/stm32f0-discovery/adc/Makefile @@ -0,0 +1,24 @@ +## +## This file is part of the libopencm3 project. +## +## Copyright (C) 2009 Uwe Hermann +## +## 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 . +## + +BINARY = adc + +LDSCRIPT = ../stm32f0-discovery.ld + +include ../../Makefile.include diff --git a/examples/stm32/f0/stm32f0-discovery/adc/README b/examples/stm32/f0/stm32f0-discovery/adc/README new file mode 100644 index 0000000..6eec4af --- /dev/null +++ b/examples/stm32/f0/stm32f0-discovery/adc/README @@ -0,0 +1,11 @@ +------------------------------------------------------------------------------ +README +------------------------------------------------------------------------------ + +This is the smallest-possible example program using libopencm3. + +It's intended for the ST STM32F0DISCOVERY eval board. It should read from the +ADC_IN1 (PA1) pin its voltage and print it to the serial port on pin PA9 with +parameters (38400,8,N,1) + + diff --git a/examples/stm32/f0/stm32f0-discovery/adc/adc.c b/examples/stm32/f0/stm32f0-discovery/adc/adc.c new file mode 100644 index 0000000..35a4349 --- /dev/null +++ b/examples/stm32/f0/stm32f0-discovery/adc/adc.c @@ -0,0 +1,131 @@ +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2009 Uwe Hermann + * Copyright (C) 2011 Stephen Caudle + * Modified by Fernando Cortes + * modified by Guillermo Rivera + * modified by Frantisek Burian + * + * 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 + +uint8_t channel_array[] = { ADC_CHANNEL1, ADC_CHANNEL1, ADC_CHANNEL_TEMP}; + +static void adc_setup(void) +{ + rcc_periph_clock_enable(RCC_ADC); + rcc_periph_clock_enable(RCC_GPIOA); + + gpio_mode_setup(GPIOA, GPIO_MODE_ANALOG, GPIO_PUPD_NONE, GPIO0); + gpio_mode_setup(GPIOA, GPIO_MODE_ANALOG, GPIO_PUPD_NONE, GPIO1); + + adc_power_off(ADC1); + adc_set_clk_source(ADC1, ADC_CLKSOURCE_ADC); + adc_calibrate_start(ADC1); + adc_calibrate_wait_finish(ADC1); + adc_set_operation_mode(ADC1, ADC_MODE_SCAN); + adc_disable_external_trigger_regular(ADC1); + adc_set_right_aligned(ADC1); + adc_enable_temperature_sensor(); + adc_set_sample_time_on_all_channels(ADC1, ADC_SMPTIME_071DOT5); + adc_set_regular_sequence(ADC1, 1, channel_array); + adc_set_resolution(ADC1, ADC_RESOLUTION_12BIT); + adc_disable_analog_watchdog(ADC1); + adc_power_on(ADC1); + + /* Wait for ADC starting up. */ + int i; + for (i = 0; i < 800000; i++) /* Wait a bit. */ + __asm__("nop"); + +} + +static void usart_setup(void) +{ + /* Enable clocks for GPIO port A (for GPIO_USART2_TX) and USART1. */ + rcc_periph_clock_enable(RCC_USART1); + rcc_periph_clock_enable(RCC_GPIOA); + + /* Setup GPIO pin GPIO_USART1_TX/GPIO9 on GPIO port A for transmit. */ + gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO9); + gpio_set_af(GPIOA, GPIO_AF1, GPIO9); + + /* Setup UART parameters. */ + usart_set_baudrate(USART1, 38400); + usart_set_databits(USART1, 8); + usart_set_stopbits(USART1, USART_CR2_STOP_1_0BIT); + usart_set_mode(USART1, USART_MODE_TX); + usart_set_parity(USART1, USART_PARITY_NONE); + usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE); + + /* Finally enable the USART. */ + usart_enable(USART1); +} + +static void my_usart_print_int(uint32_t usart, int16_t value) +{ + int8_t i; + int8_t nr_digits = 0; + char buffer[25]; + + if (value < 0) { + usart_send_blocking(usart, '-'); + value = value * -1; + } + + if (value == 0) { + usart_send_blocking(usart, '0'); + } + + 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'); + usart_send_blocking(usart, '\n'); +} + +int main(void) +{ + uint16_t temp; + + adc_setup(); + usart_setup(); + + while (1) { + adc_start_conversion_regular(ADC1); + while (!(adc_eoc(ADC1))); + + temp = adc_read_regular(ADC1); + my_usart_print_int(USART1, temp); + + int i; + for (i = 0; i < 800000; i++) /* Wait a bit. */ + __asm__("nop"); + } + + return 0; +} +