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Diffstat (limited to 'examples/stm32/f1/other/i2c_stts75_sensor/i2c_stts75_sensor.c')
-rw-r--r--examples/stm32/f1/other/i2c_stts75_sensor/i2c_stts75_sensor.c146
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diff --git a/examples/stm32/f1/other/i2c_stts75_sensor/i2c_stts75_sensor.c b/examples/stm32/f1/other/i2c_stts75_sensor/i2c_stts75_sensor.c
new file mode 100644
index 0000000..d8f2404
--- /dev/null
+++ b/examples/stm32/f1/other/i2c_stts75_sensor/i2c_stts75_sensor.c
@@ -0,0 +1,146 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include <libopencm3/stm32/f1/rcc.h>
+#include <libopencm3/stm32/f1/flash.h>
+#include <libopencm3/stm32/f1/gpio.h>
+#include <libopencm3/stm32/usart.h>
+#include <libopencm3/stm32/i2c.h>
+#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, rcc_ppre2_frequency);
+ 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;
+}