From bcce98da54b047a15ef0abf41e0c7794f29f0439 Mon Sep 17 00:00:00 2001 From: Uwe Hermann Date: Thu, 30 Dec 2010 01:52:44 +0100 Subject: Move STM32 examples to examples/stm32 subdir. --- .../other/i2c_stts75_sensor/i2c_stts75_sensor.c | 146 +++++++++++++++++++++ 1 file changed, 146 insertions(+) create mode 100644 examples/stm32/other/i2c_stts75_sensor/i2c_stts75_sensor.c (limited to 'examples/stm32/other/i2c_stts75_sensor/i2c_stts75_sensor.c') diff --git a/examples/stm32/other/i2c_stts75_sensor/i2c_stts75_sensor.c b/examples/stm32/other/i2c_stts75_sensor/i2c_stts75_sensor.c new file mode 100644 index 0000000..1227fd1 --- /dev/null +++ b/examples/stm32/other/i2c_stts75_sensor/i2c_stts75_sensor.c @@ -0,0 +1,146 @@ +/* + * This file is part of the libopenstm32 project. + * + * Copyright (C) 2010 Thomas Otto + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include +#include +#include +#include +#include +#include "stts75.h" + +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_APB2ENR, RCC_APB2ENR_USART1EN); + + /* 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_USART1_TX); + + /* Setup UART parameters. */ + usart_set_baudrate(USART1, 115200); + usart_set_databits(USART1, 8); + usart_set_stopbits(USART1, USART_STOPBITS_1); + usart_set_mode(USART1, USART_MODE_TX_RX); + usart_set_parity(USART1, USART_PARITY_NONE); + usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE); + + /* Finally enable the USART. */ + usart_enable(USART1); +} + +void gpio_setup(void) +{ + /* Enable GPIOB clock. */ + rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN); + + /* Set GPIO6/7 (in GPIO port B) to 'output push-pull' for the LEDs. */ + gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO6); + gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO7); +} + +void i2c_setup(void) +{ + /* Enable clocks for I2C2 and AFIO. */ + rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_I2C2EN); + rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_AFIOEN); + + /* Set alternate functions for the SCL and SDA pins of I2C2. */ + gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, + GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN, + GPIO_I2C2_SCL | GPIO_I2C2_SDA); + + /* Disable the I2C before changing any configuration. */ + i2c_peripheral_disable(I2C2); + + /* APB1 is running at 36MHz. */ + i2c_set_clock_frequency(I2C2, I2C_CR2_FREQ_36MHZ); + + /* 400KHz - I2C Fast Mode */ + i2c_set_fast_mode(I2C2); + + /* + * fclock for I2C is 36MHz APB2 -> cycle time 28ns, low time at 400KHz + * incl trise -> Thigh= 1600ns; CCR= tlow/tcycle= 0x1C,9; + * datasheet suggests 0x1e. + */ + i2c_set_ccr(I2C2, 0x1e); + + /* + * fclock for I2C is 36MHz -> cycle time 28ns, rise time for + * 400KHz => 300ns and 100KHz => 1000ns; 300ns/28ns = 10; + * incremented by 1 -> 11. + */ + i2c_set_trise(I2C2, 0x0b); + + /* + * This is our slave address - needed only if we want to receive from + * other masters. + */ + i2c_set_own_7bit_slave_address(I2C2, 0x32); + + /* If everything is configured -> enable the peripheral. */ + i2c_peripheral_enable(I2C2); +} + +int main(void) +{ + int i = 0; + u16 temperature; + + rcc_clock_setup_in_hse_16mhz_out_72mhz(); + gpio_setup(); + usart_setup(); + i2c_setup(); + + gpio_clear(GPIOB, GPIO7); /* LED1 on */ + gpio_set(GPIOB, GPIO6); /* LED2 off */ + + /* Send a message on USART1. */ + usart_send(USART1, 's'); + usart_send(USART1, 't'); + usart_send(USART1, 'm'); + usart_send(USART1, '\r'); + usart_send(USART1, '\n'); + + stts75_write_config(I2C2, STTS75_SENSOR0); + stts75_write_temp_os(I2C2, STTS75_SENSOR0, 0x1a00); /* 26 degrees */ + stts75_write_temp_hyst(I2C2, STTS75_SENSOR0, 0x1a00); + temperature = stts75_read_temperature(I2C2, STTS75_SENSOR0); + + /* Send the temperature as binary over USART1. */ + for (i = 15; i >= 0 ; i--) { + if (temperature & (1 << i)) + usart_send(USART1, '1'); + else + usart_send(USART1, '0'); + } + + usart_send(USART1, '\r'); + usart_send(USART1, '\n'); + + gpio_clear(GPIOB, GPIO6); /* LED2 on */ + + while(1); /* Halt. */ + + return 0; +} -- cgit v1.2.3