BV I2C: add initial I2C support
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/* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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/** BusVoodoo I²C mode (code)
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* @file busvoodoo_i2c.c
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* @author King Kévin <kingkevin@cuvoodoo.info>
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* @date 2018
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* @note peripherals used: I2C @ref busvoodoo_i2c
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*/
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/* standard libraries */
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#include <stdint.h> // standard integer types
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#include <stdlib.h> // standard utilities
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#include <string.h> // string utilities
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/* STM32 (including CM3) libraries */
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#include <libopencm3/stm32/gpio.h> // general purpose input output library
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#include <libopencm3/stm32/rcc.h> // real-time control clock library
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/* own libraries */
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#include "global.h" // board definitions
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#include "print.h" // printing utilities
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#include "menu.h" // menu definitions
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#include "i2c_general.h" // I2C utilities
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#include "busvoodoo_global.h" // BusVoodoo definitions
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#include "busvoodoo_oled.h" // OLED utilities
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#include "busvoodoo_i2c.h" // own definitions
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/** mode setup stage */
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static enum busvoodoo_i2c_setting_t {
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BUSVOODOO_I2C_SETTING_NONE,
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BUSVOODOO_I2C_SETTING_SPEED,
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BUSVOODOO_I2C_SETTING_ADDRESSBITS,
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BUSVOODOO_I2C_SETTING_PULLUP,
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BUSVOODOO_I2C_SETTING_DONE,
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} busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_NONE;
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/** I2C speed (in kHz) */
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uint16_t busvoodoo_i2c_speed = 100;
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/** I2C address bits (7 or 10) */
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uint8_t busvoodoo_i2c_addressbits = 7;
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/** if embedded or external pull-up resistors are use */
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bool busvoodoo_i2c_embedded_pullup = true;
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/** setup I2C mode
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* @param[out] prefix terminal prompt prefix
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* @param[in] line terminal prompt line to configure mode
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* @return if setup is complete
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*/
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static bool busvoodoo_i2c_setup(char** prefix, const char* line)
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{
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bool complete = false; // is the setup complete
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static char config[32] = {0}; // configuration string used as prefix
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if (NULL==line) { // first call
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_NONE; // re-start configuration
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}
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switch (busvoodoo_i2c_setting) {
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case BUSVOODOO_I2C_SETTING_NONE:
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snprintf(config, LENGTH(config), "speed in kHz (1-400) [%u]", busvoodoo_i2c_speed);
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*prefix = config; // ask for speed
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_SPEED;
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break;
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case BUSVOODOO_I2C_SETTING_SPEED:
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if (NULL==line || 0==strlen(line)) { // use default setting
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_ADDRESSBITS; // go to next setting
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} else { // setting provided
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uint32_t speed = atoi(line); // parse setting
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if (speed>0 && speed<=400) { // check setting
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busvoodoo_i2c_speed = speed; // remember setting
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_ADDRESSBITS; // go to next setting
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}
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}
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if (BUSVOODOO_I2C_SETTING_ADDRESSBITS==busvoodoo_i2c_setting) { // if next setting
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snprintf(config, LENGTH(config), "address size in bits (7,10) [%u]", busvoodoo_i2c_addressbits); // prepare next setting
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*prefix = config; // display next setting
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}
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break;
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case BUSVOODOO_I2C_SETTING_ADDRESSBITS:
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if (NULL==line || 0==strlen(line)) { // use default setting
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_PULLUP; // go to next setting
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} else { // setting provided
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uint8_t addressbits = atoi(line); // parse setting
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if (7==addressbits || 10==addressbits) { // check setting
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busvoodoo_i2c_addressbits = addressbits; // remember setting
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_PULLUP; // go to next setting
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}
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}
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if (BUSVOODOO_I2C_SETTING_PULLUP==busvoodoo_i2c_setting) { // if next setting
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printf("i) embedded\n");
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printf("e) external\n");
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snprintf(config, LENGTH(config), "pull-up resistors (i,e) [%c]", busvoodoo_i2c_embedded_pullup ? 'i' : 'e'); // prepare next setting
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*prefix = config; // display next setting
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}
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break;
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case BUSVOODOO_I2C_SETTING_PULLUP:
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if (NULL==line || 0==strlen(line)) { // use default setting
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_DONE; // go to next setting
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} else { // setting provided
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if (0==strcmp("i", line)) { // check setting
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busvoodoo_i2c_embedded_pullup = true; // remember setting
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_DONE; // go to next setting
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} else if (0==strcmp("e", line)) {
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busvoodoo_i2c_embedded_pullup = false; // remember setting
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_DONE; // go to next setting
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}
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}
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if (BUSVOODOO_I2C_SETTING_DONE==busvoodoo_i2c_setting) { // we have all settings, configure I2C
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i2c_general_setup_master(false); // setup I2C
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busvoodoo_embedded_pullup(busvoodoo_i2c_embedded_pullup); // set pull-up
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if (busvoodoo_i2c_embedded_pullup) {
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printf("set pull-up voltage with LV\n");
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}
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led_off(); // disable LED because there is no activity
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_NONE; // restart settings next time
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*prefix = "I2C"; // display mode
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busvoodoo_oled_text_left(*prefix); // set mode title on OLED display
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const char* pinout_io[10] = {"GND", "3V3", "5V", "LV", "SDA", "SCL", NULL, NULL}; // HiZ mode pinout
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for (uint8_t i=0; i<LENGTH(pinout_io) && i<LENGTH(busvoodoo_global_pinout_io); i++) {
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busvoodoo_global_pinout_io[i] = pinout_io[i]; // set pin names
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}
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busvoodoo_oled_text_pinout(pinout_io, true); // set pinout on display
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busvoodoo_oled_update(); // update display to show text and pinout
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complete = true; // configuration is complete
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}
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break;
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case BUSVOODOO_I2C_SETTING_DONE: // this case is already handled before
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default: // unknown case
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busvoodoo_i2c_setting = BUSVOODOO_I2C_SETTING_NONE; // restart settings next time
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complete = false; // restart setting
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break;
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}
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return complete;
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}
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/** exit I2C mode
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*/
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static void busvoodoo_i2c_exit(void)
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{
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// TODO release I2C periph
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busvoodoo_embedded_pullup(false); // disable embedded pull-ups
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}
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// command handlers
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/** command to scan for slave devices
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* @param[in] argument no argument required
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*/
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static void busvoodoo_i2c_command_scan(void* argument)
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{
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(void)argument; // we won't use the argument
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if (!i2c_general_check()) { // ensure SCL and SDA are high
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printf("SCL or SDA is low. The signals need to be pulled up\n");
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if (busvoodoo_i2c_embedded_pullup) {
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printf("set pull-up voltage with LV\n");
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}
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led_blink(0.5, 0.5); // show error on LEDs
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return; // stop here
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} else {
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led_off(); // switch LEDs off
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}
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printf("scanning for I2C slaves\n");
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uint16_t i2c_slaves = 0; // number of slaves found
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// check for I2C slaves by going through the address space
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for (uint16_t address=0; address < (1<<busvoodoo_i2c_addressbits); address++) {
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if (!i2c_general_start()) { // send start condition
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i2c_general_stop(); // send stop condition
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printf("start condition failed\n"); // show error to user
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led_blink(0.5, 0.5); // show error on LEDs
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break; // stop scanning
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} else {
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busvoodoo_led_blue(100); // pulse blue LED to show transmission
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}
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if (i2c_general_select_slave(address, false)) { // try to select slave
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busvoodoo_led_red(100); // pulse red LED to show we found a slave
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printf((busvoodoo_i2c_addressbits>7) ? "0x%03x " : "0x%02x ", address); // display address
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i2c_slaves++; // increase slave count
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}
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i2c_general_stop(); // send stop condition
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}
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if (i2c_slaves>0) {
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printf("\n");
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}
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printf("%u slave(s) found\n", i2c_slaves); // show summary
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}
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static const struct menu_command_t busvoodoo_i2c_commands[] = {
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{
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's',
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"scan",
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"scan for slave devices",
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MENU_ARGUMENT_NONE,
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NULL,
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&busvoodoo_i2c_command_scan,
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},
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};
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struct busvoodoo_mode_t busvoodoo_i2c_mode = {
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"i2c",
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"Inter-Integrated Circuit",
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&busvoodoo_i2c_setup,
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busvoodoo_i2c_commands,
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LENGTH(busvoodoo_i2c_commands),
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&busvoodoo_i2c_exit,
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};
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@ -0,0 +1,23 @@
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/* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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/** BusVoodoo I²C mode (API)
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* @file busvoodoo_i2c.h
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* @author King Kévin <kingkevin@cuvoodoo.info>
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* @date 2018
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* @note peripherals used: I2C @ref busvoodoo_i2c
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*/
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/** I2C mode interface definition */
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extern struct busvoodoo_mode_t busvoodoo_i2c_mode;
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/* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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/** library to communicate using I2C as master or slave (code)
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* @file i2c_general.c
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* @author King Kévin <kingkevin@cuvoodoo.info>
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* @date 2017-2018
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* @note peripherals used: I2C @ref i2c_general_i2c, timer @ref i2c_general_timer
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*/
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/* standard libraries */
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#include <stdint.h> // standard integer types
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//#include <stdio.h> // standard I/O facilities
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#include <stdlib.h> // general utilities
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/* STM32 (including CM3) libraries */
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#include <libopencm3/stm32/rcc.h> // real-time control clock library
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#include <libopencm3/stm32/gpio.h> // general purpose input output library
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#include <libopencm3/stm32/i2c.h> // I2C library
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#include <libopencm3/stm32/timer.h> // timer utilities
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/* own libraries */
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#include "global.h" // global utilities
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#include "i2c_general.h" // I2C header and definitions
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/** @defgroup i2c_general_i2c I2C peripheral used to communicate
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* @{
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*/
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#define I2C_GENERAL_I2C 2 /**< I2C peripheral */
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/** @} */
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/** @defgroup i2c_general_timer timer peripheral used for timeouts
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* @{
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*/
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#define I2C_GENERAL_TIMER 3 /**< timer peripheral */
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#define I2C_GENERAL_TIMEOUT 4 /**< timeout factor (compared to expected time) */
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/** @} */
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void i2c_general_setup_master(bool fast)
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{
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// configure I2C peripheral
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rcc_periph_clock_enable(RCC_I2C_SCL_PORT(I2C_GENERAL_I2C)); // enable clock for I2C I/O peripheral
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gpio_set(I2C_SCL_PORT(I2C_GENERAL_I2C), I2C_SCL_PIN(I2C_GENERAL_I2C)); // already put signal high to avoid small pulse
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gpio_set_mode(I2C_SCL_PORT(I2C_GENERAL_I2C), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN, I2C_SCL_PIN(I2C_GENERAL_I2C)); // setup I2C I/O pins
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rcc_periph_clock_enable(RCC_I2C_SCL_PORT(I2C_GENERAL_I2C)); // enable clock for I2C I/O peripheral
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gpio_set(I2C_SDA_PORT(I2C_GENERAL_I2C), I2C_SDA_PIN(I2C_GENERAL_I2C)); // already put signal high to avoid small pulse
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gpio_set_mode(I2C_SDA_PORT(I2C_GENERAL_I2C), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN, I2C_SDA_PIN(I2C_GENERAL_I2C)); // setup I2C I/O pins
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rcc_periph_clock_enable(RCC_AFIO); // enable clock for alternate function
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rcc_periph_clock_enable(RCC_I2C(I2C_GENERAL_I2C)); // enable clock for I2C peripheral
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i2c_reset(I2C(I2C_GENERAL_I2C)); // reset configuration
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i2c_peripheral_disable(I2C(I2C_GENERAL_I2C)); // I2C needs to be disable to be configured
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i2c_set_clock_frequency(I2C(I2C_GENERAL_I2C), rcc_apb1_frequency/1000000); // configure the peripheral clock to the APB1 freq (where it is connected to)
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if (fast) {
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i2c_set_fast_mode(I2C(I2C_GENERAL_I2C));
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i2c_set_ccr(I2C(I2C_GENERAL_I2C), rcc_apb1_frequency/(400000*2)); // set Thigh/Tlow to generate frequency of 400 kHz
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i2c_set_trise(I2C(I2C_GENERAL_I2C), (300/(1000/(rcc_apb1_frequency/1000000)))+1); // max rise time for 300 kHz is 300 ns
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} else {
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i2c_set_standard_mode(I2C(I2C_GENERAL_I2C)); // the DS1307 has a maximum I2C SCL freq if 100 kHz (corresponding to the standard mode)
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i2c_set_ccr(I2C(I2C_GENERAL_I2C), rcc_apb1_frequency/(100000*2)); // set Thigh/Tlow to generate frequency of 100 kHz
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i2c_set_trise(I2C(I2C_GENERAL_I2C), (1000/(1000/(rcc_apb1_frequency/1000000)))+1); // max rise time for 100 kHz is 1000 ns (~1 MHz)
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}
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i2c_peripheral_enable(I2C(I2C_GENERAL_I2C)); // enable I2C after configuration completed
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// configure time for timeouts
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rcc_periph_clock_enable(RCC_TIM(I2C_GENERAL_TIMER)); // enable clock for timer block
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timer_reset(TIM(I2C_GENERAL_TIMER)); // reset timer state
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timer_set_mode(TIM(I2C_GENERAL_TIMER), TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP); // set timer mode, use undivided timer clock, edge alignment (simple count), and count up
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timer_one_shot_mode(TIM(I2C_GENERAL_TIMER)); // stop counter after update event (we only need to one timeout and reset before next operation)
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if (fast) {
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timer_set_prescaler(TIM(I2C_GENERAL_TIMER), rcc_ahb_frequency/400000-1); // set the prescaler so one tick is also one I2C bit (used I2C frequency)
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} else {
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timer_set_prescaler(TIM(I2C_GENERAL_TIMER), rcc_ahb_frequency/100000-1); // set the prescaler so one tick is also one I2C bit (used I2C frequency)
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}
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timer_set_period(TIM(I2C_GENERAL_TIMER), I2C_GENERAL_TIMEOUT*9); // use factor to wait for all 9 bits to be transmitted
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timer_update_on_overflow(TIM(I2C_GENERAL_TIMER)); // only use counter overflow as UEV source (use overflow as timeout)
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// wait one transaction for the signal to be stable (some slave have issues when an I2C transaction immediately follows)
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timer_set_counter(TIM(I2C_GENERAL_TIMER),0); // restart timer
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timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
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timer_enable_counter(TIM(I2C_GENERAL_TIMER)); // enable timer for timeouts
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while ( !timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF));
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timer_disable_counter(TIM(I2C_GENERAL_TIMER)); // disable timer for timeouts
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timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
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}
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bool i2c_general_check(void)
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{
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return (0!=gpio_get(I2C_SCL_PORT(I2C_GENERAL_I2C), I2C_SCL_PIN(I2C_GENERAL_I2C)) && 0!=gpio_get(I2C_SDA_PORT(I2C_GENERAL_I2C), I2C_SDA_PIN(I2C_GENERAL_I2C)));
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}
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bool i2c_general_start(void)
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{
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// send (re-)start condition
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i2c_send_start(I2C(I2C_GENERAL_I2C)); // send start condition to start transaction
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timer_set_counter(TIM(I2C_GENERAL_TIMER), 0); // restart timer
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timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
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timer_enable_counter(TIM(I2C_GENERAL_TIMER)); // enable timer for timeouts
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while (!(I2C_SR1(I2C(I2C_GENERAL_I2C)) & I2C_SR1_SB) && !timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF)); // wait until start condition is transmitted
|
||||
timer_disable_counter(TIM(I2C_GENERAL_TIMER)); // disable timer for timeouts
|
||||
if (timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF)) { // timeout occurred
|
||||
timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
|
||||
return false;
|
||||
}
|
||||
if (!(I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_MSL)) { // verify if in master mode
|
||||
return false;
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
bool i2c_general_select_slave(uint8_t slave, bool write)
|
||||
{
|
||||
if (!(I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_BUSY)) { // I2C device is not busy (start condition has not been sent)
|
||||
if (!i2c_general_start()) { // send start condition
|
||||
return false; // could not send start condition
|
||||
}
|
||||
}
|
||||
if (!(I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_MSL)) { // I2C device is already not master mode
|
||||
return false;
|
||||
}
|
||||
|
||||
// select slave
|
||||
i2c_send_7bit_address(I2C(I2C_GENERAL_I2C), slave, write ? I2C_WRITE : I2C_READ); // select slave, with read/write flag
|
||||
timer_set_counter(TIM(I2C_GENERAL_TIMER), 0); // restart timer
|
||||
timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
|
||||
timer_enable_counter(TIM(I2C_GENERAL_TIMER)); // enable timer for timeouts
|
||||
while (!(I2C_SR1(I2C(I2C_GENERAL_I2C)) & I2C_SR1_ADDR) && !timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF)); // wait until address is transmitted
|
||||
timer_disable_counter(TIM(I2C_GENERAL_TIMER)); // disable timer for timeouts
|
||||
if (timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF)) { // timeout occurred (no ACK received)
|
||||
timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
|
||||
return false;
|
||||
}
|
||||
if (write) {
|
||||
if (!((I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_TRA))) { // verify we are in transmit mode (and read SR2 to clear ADDR)
|
||||
return false;
|
||||
}
|
||||
} else {
|
||||
if ((I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_TRA)) { // verify we are in read mode (and read SR2 to clear ADDR)
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
bool i2c_general_read(uint8_t* data, size_t data_size)
|
||||
{
|
||||
// sanity check
|
||||
if (data==NULL || data_size==0) { // no data to read
|
||||
return true;
|
||||
}
|
||||
if (!(I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_BUSY)) { // I2C device is not busy (start condition has not been sent)
|
||||
return false; // address has probably also not been sent
|
||||
}
|
||||
if (!(I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_MSL)) { // I2C device not master mode
|
||||
return false;
|
||||
}
|
||||
|
||||
// read data
|
||||
for (size_t i=0; i<data_size; i++) { // read bytes
|
||||
if (i==data_size-1) { // prepare to sent NACK for last byte
|
||||
i2c_disable_ack(I2C(I2C_GENERAL_I2C)); // NACK received to stop slave transmission
|
||||
i2c_send_stop(I2C(I2C_GENERAL_I2C)); // send STOP after receiving byte
|
||||
} else {
|
||||
i2c_enable_ack(I2C(I2C_GENERAL_I2C)); // ACK received byte to continue slave transmission
|
||||
}
|
||||
timer_set_counter(TIM(I2C_GENERAL_TIMER), 0); // restart timer
|
||||
timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
|
||||
timer_enable_counter(TIM(I2C_GENERAL_TIMER)); // enable timer for timeouts
|
||||
while (!(I2C_SR1(I2C(I2C_GENERAL_I2C)) & I2C_SR1_RxNE) && !timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF)); // wait until byte has been received
|
||||
timer_disable_counter(TIM(I2C_GENERAL_TIMER)); // disable timer for timeouts
|
||||
if (timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF)) { // timeout occurred
|
||||
timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
|
||||
return false;
|
||||
}
|
||||
data[i] = i2c_get_data(I2C(I2C_GENERAL_I2C)); // read received byte
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
bool i2c_general_write(const uint8_t* data, size_t data_size)
|
||||
{
|
||||
// sanity check
|
||||
if (data==NULL || data_size==0) { // no data to write
|
||||
return true;
|
||||
}
|
||||
if (!(I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_BUSY)) { // I2C device is not busy (start condition has not been sent)
|
||||
return false; // address has probably also not been sent
|
||||
}
|
||||
if (!(I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_MSL)) { // I2C device is not master mode
|
||||
return false;
|
||||
}
|
||||
|
||||
// write data
|
||||
for (size_t i=0; i<data_size; i++) { // write bytes
|
||||
i2c_send_data(I2C(I2C_GENERAL_I2C), data[i]); // send byte to be written in memory
|
||||
timer_set_counter(TIM(I2C_GENERAL_TIMER),0); // restart timer
|
||||
timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
|
||||
timer_enable_counter(TIM(I2C_GENERAL_TIMER)); // enable timer for timeouts
|
||||
while (!(I2C_SR1(I2C(I2C_GENERAL_I2C)) & I2C_SR1_TxE) && !timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF)); // wait until byte has been transmitted
|
||||
timer_disable_counter(TIM(I2C_GENERAL_TIMER)); // disable timer for timeouts
|
||||
if (timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF)) { // timeout occurred (no ACK received)
|
||||
timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
void i2c_general_stop(void)
|
||||
{
|
||||
// sanity check
|
||||
if (!(I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_BUSY)) { // release is not busy
|
||||
return; // bus has probably already been released
|
||||
}
|
||||
|
||||
// send stop condition
|
||||
i2c_send_stop(I2C(I2C_GENERAL_I2C)); // send stop to release bus
|
||||
timer_set_counter(TIM(I2C_GENERAL_TIMER), 0); // restart timer
|
||||
timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
|
||||
timer_enable_counter(TIM(I2C_GENERAL_TIMER)); // enable timer for timeouts
|
||||
while ((I2C_SR2(I2C(I2C_GENERAL_I2C)) & I2C_SR2_MSL) && !timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF)); // wait until bus released (non master mode)
|
||||
timer_disable_counter(TIM(I2C_GENERAL_TIMER)); // disable timer for timeouts
|
||||
if (timer_get_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF)) { // timeout occurred
|
||||
timer_clear_flag(TIM(I2C_GENERAL_TIMER), TIM_SR_UIF); // clear flag
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,56 @@
|
|||
/* 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/>.
|
||||
*
|
||||
*/
|
||||
/** library to communicate using I2C as master or slave (API)
|
||||
* @file i2c_general.h
|
||||
* @author King Kévin <kingkevin@cuvoodoo.info>
|
||||
* @date 2018
|
||||
* @note peripherals used: I2C @ref i2c_general_i2c, timer @ref i2c_general_timer
|
||||
* @warning only 7-byte I2C slave addresses are supported
|
||||
*/
|
||||
#pragma once
|
||||
|
||||
/** setup I2C peripheral
|
||||
* @param[in] fast use standard (100 kHz) or fast (400 kHz) mode
|
||||
*/
|
||||
void i2c_general_setup_master(bool fast);
|
||||
/** check if SDA and SCL signals are high
|
||||
* @return SDA and SCL signals are high
|
||||
*/
|
||||
bool i2c_general_check(void);
|
||||
/** send start condition
|
||||
* @return if start condition was sent successfully (true) or error occurred (false)
|
||||
*/
|
||||
bool i2c_general_start(void);
|
||||
/** select slave device
|
||||
* @warning a start condition should be sent before this operation
|
||||
* @param[in] slave 7-bit I2C address of slave device to select
|
||||
* @param[in] write this transaction will be followed by a read (false) or write (true) operation
|
||||
* @return if slave was selected successfully (true) or error occurred (false)
|
||||
*/
|
||||
bool i2c_general_select_slave(uint8_t slave, bool write);
|
||||
/** read data
|
||||
* @warning the slave device must be selected before this operation
|
||||
* @param[out] data array to store bytes read
|
||||
* @param[in] data_size number of bytes to read
|
||||
*/
|
||||
bool i2c_general_read(uint8_t* data, size_t data_size);
|
||||
/** write data
|
||||
* @warning the slave device must be selected before this operation
|
||||
* @param[in] data array of byte to write to slave
|
||||
* @param[in] data_size number of bytes to write
|
||||
*/
|
||||
bool i2c_general_write(const uint8_t* data, size_t data_size);
|
||||
/** sent stop condition */
|
||||
void i2c_general_stop(void);
|
||||
Loading…
Reference in New Issue