From d30f38ed3c2bf38ef57dd14fac672722b480927c Mon Sep 17 00:00:00 2001 From: Karl Palsson Date: Tue, 21 Feb 2017 23:32:50 +0000 Subject: i2c-master: start extracting out i2c code Working on f4 with an external sht21 i2c sensor. Still lots of f4 specifics yet. But, progress. --- tests/i2c-master/i2c-master.c | 185 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 183 insertions(+), 2 deletions(-) (limited to 'tests/i2c-master/i2c-master.c') diff --git a/tests/i2c-master/i2c-master.c b/tests/i2c-master/i2c-master.c index 64c9cfe..2c8e604 100644 --- a/tests/i2c-master/i2c-master.c +++ b/tests/i2c-master/i2c-master.c @@ -2,22 +2,203 @@ * Feb 2017, Karl Palsson */ +#include +#include +#include #include #include +#include "trace.h" #include "hw.h" #include "i2c-master.h" +#define SENSOR_ADDRESS (0x40) -void i2cm_init(void) { +enum sht21_cmd_e { + SHT21_CMD_TEMP_HOLD = 0xe3, + SHT21_CMD_HUMIDITY_HOLD = 0xe5, + SHT21_CMD_TEMP_NOHOLD = 0xf3, + SHT21_CMD_HUMIDITY_NOHOLD = 0xf5, + SHT21_CMD_WRITE_REG = 0xe6, + SHT21_CMD_READ_REG = 0xe7, + SHT21_CMD_RESET = 0xfe, + /* 0xfa, 0x0f to read serial */ +}; + +void i2cm_init(void) +{ rcc_periph_clock_enable(hw_details.periph_rcc); rcc_periph_reset_pulse(hw_details.periph_rst); i2c_set_standard_mode(hw_details.periph); - i2c_enable_ack(hw_details.periph); + // i2c_enable_ack(hw_details.periph); /* NO ACK FOR SHT21! */ //i2c_set_dutycycle(hw_details.periph, I2C_CCR_DUTY_DIV2); /* default, no need to do this really */ + + /* --------- board specific settings! */ i2c_set_clock_frequency(hw_details.periph, I2C_CR2_FREQ_42MHZ); /* 42MHz / (100kHz * 2) */ i2c_set_ccr(hw_details.periph, 210); /* standard mode, freqMhz+1*/ i2c_set_trise(hw_details.periph, 43); + /* --------- end of board specific settings!*/ + i2c_peripheral_enable(hw_details.periph); +} + +static void sht21_send_data(uint32_t i2c, size_t n, uint8_t *data) +{ + while ((I2C_SR2(i2c) & I2C_SR2_BUSY)) { + } + + i2c_send_start(i2c); + + /* Wait for master mode selected */ + while (!((I2C_SR1(i2c) & I2C_SR1_SB) + & (I2C_SR2(i2c) & (I2C_SR2_MSL | I2C_SR2_BUSY)))); + + i2c_send_7bit_address(i2c, SENSOR_ADDRESS, I2C_WRITE); + + /* Waiting for address is transferred. */ + while (!(I2C_SR1(i2c) & I2C_SR1_ADDR)); + + /* Cleaning ADDR condition sequence. */ + uint32_t reg32 = I2C_SR2(i2c); + (void) reg32; /* unused */ + + size_t i; + for (i = 0; i < n; i++) { + i2c_send_data(i2c, data[i]); + while (!(I2C_SR1(i2c) & (I2C_SR1_BTF))); + } +} + +static void sht21_send_cmd(uint32_t i2c, uint8_t cmd) +{ + while ((I2C_SR2(i2c) & I2C_SR2_BUSY)) { + } + + i2c_send_start(i2c); + + /* Wait for master mode selected */ + while (!((I2C_SR1(i2c) & I2C_SR1_SB) + & (I2C_SR2(i2c) & (I2C_SR2_MSL | I2C_SR2_BUSY)))); + + i2c_send_7bit_address(i2c, SENSOR_ADDRESS, I2C_WRITE); + + /* Waiting for address is transferred. */ + while (!(I2C_SR1(i2c) & I2C_SR1_ADDR)); + + /* Cleaning ADDR condition sequence. */ + uint32_t reg32 = I2C_SR2(i2c); + (void) reg32; /* unused */ + + i2c_send_data(i2c, cmd); + while (!(I2C_SR1(i2c) & (I2C_SR1_BTF))); +} + +static void sht21_readn(uint32_t i2c, int n, uint8_t *res) +{ + //assert(n > 0); + i2c_send_start(i2c); + + i2c_enable_ack(i2c); + + /* Wait for master mode selected */ + while (!((I2C_SR1(i2c) & I2C_SR1_SB) + & (I2C_SR2(i2c) & (I2C_SR2_MSL | I2C_SR2_BUSY)))); + + i2c_send_7bit_address(i2c, SENSOR_ADDRESS, I2C_READ); + + /* Waiting for address is transferred. */ + while (!(I2C_SR1(i2c) & I2C_SR1_ADDR)); + /* Cleaning ADDR condition sequence. */ + uint32_t reg32 = I2C_SR2(i2c); + (void) reg32; /* unused */ + + int i = 0; + for (i = 0; i < n; ++i) { + if (i == n - 1) { + i2c_disable_ack(i2c); + } + while (!(I2C_SR1(i2c) & I2C_SR1_RxNE)); + res[i] = i2c_get_data(i2c); + } + i2c_send_stop(i2c); + + return; +} + +static float sht21_convert_temp(uint16_t raw) +{ + //assert((raw & 0x2) == 0x2); + raw &= ~0x3; /* Clear lower status bits */ + float tf = -46.85 + 175.72 * ((float) raw / 65536.0); + return tf; +} + +static float sht21_convert_humi(uint16_t raw) +{ + //assert((raw & 0x2) == 0); + raw &= ~0x3; /* Clear lower status bits */ + float tf = -6 + 125 * ((float) raw / 65536.0); + return tf; +} + +static float sht21_read_temp_hold(uint32_t i2c) +{ + // gpio_set(LED_DISCO_BLUE_PORT, LED_DISCO_BLUE_PIN); + sht21_send_cmd(i2c, SHT21_CMD_TEMP_HOLD); + + uint8_t data[3]; + sht21_readn(i2c, 2, data); + uint8_t crc = data[2]; + uint16_t temp = data[0] << 8 | data[1]; + printf("CRC=%#x, data0=%#x, data1=%#x\n", crc, data[0], data[1]); + // gpio_clear(LED_DISCO_BLUE_PORT, LED_DISCO_BLUE_PIN); + return sht21_convert_temp(temp); +} + +static float sht21_read_humi_hold(uint32_t i2c) +{ + // gpio_set(LED_DISCO_BLUE_PORT, LED_DISCO_BLUE_PIN); + sht21_send_cmd(i2c, SHT21_CMD_HUMIDITY_HOLD); + + uint8_t data[3]; + sht21_readn(i2c, 2, data); + uint8_t crc = data[2]; + uint16_t left = data[0] << 8 | data[1]; + printf("CRC=%#x, data0=%#x, data1=%#x\n", crc, data[0], data[1]); + + // gpio_clear(LED_DISCO_BLUE_PORT, LED_DISCO_BLUE_PIN); + return sht21_convert_humi(left); +} + +static void sht21_readid(void) +{ + sht21_send_cmd(I2C1, SHT21_CMD_READ_REG); + uint8_t raw; + sht21_readn(I2C1, 1, &raw); + printf("raw user reg = %#x\n", raw); + int resolution = ((raw & 0x80) >> 6) | (raw & 1); + printf("temp resolution is in %d bits\n", 14 - resolution); + printf("battery status: %s\n", (raw & (1 << 6) ? "failing" : "good")); + printf("On chip heater: %s\n", (raw & 0x2) ? "on" : "off"); + + uint8_t req1[] = {0xfa, 0x0f}; + uint8_t res[8]; + sht21_send_data(I2C1, 2, req1); + sht21_readn(I2C1, sizeof(res), res); + uint8_t req2[] = {0xfc, 0xc9}; + uint8_t res2[8]; + sht21_send_data(I2C1, 2, req2); + sht21_readn(I2C1, sizeof(res), res2); + printf("Serial = %02x%02x %02x%02x %02x%02x %02x%02x\n", + res2[3], res2[4], res[0], res[2], res[4], res[6], res2[0], res2[1]); +} + +void i2cm_task(void) +{ + sht21_readid(); + float temp = sht21_read_temp_hold(I2C1); + float humi = sht21_read_humi_hold(I2C1); + printf("Temp: %f C, RH: %f\n", temp, humi); + } \ No newline at end of file -- cgit