You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
392 lines
12 KiB
392 lines
12 KiB
/*
|
|
|
|
I2C MODULE
|
|
|
|
Copyright (C) 2017-2018 by Xose Pérez <xose dot perez at gmail dot com>
|
|
|
|
Module key prefix: i2c
|
|
|
|
*/
|
|
|
|
#if I2C_SUPPORT
|
|
|
|
unsigned int _i2c_locked[16] = {0};
|
|
|
|
#if I2C_USE_BRZO
|
|
#include "brzo_i2c.h"
|
|
unsigned long _i2c_scl_frequency = 0;
|
|
#else
|
|
#include "Wire.h"
|
|
#endif
|
|
|
|
// -----------------------------------------------------------------------------
|
|
// Private
|
|
// -----------------------------------------------------------------------------
|
|
|
|
int _i2cClearbus(int sda, int scl) {
|
|
|
|
#if defined(TWCR) && defined(TWEN)
|
|
// Disable the Atmel 2-Wire interface so we can control the SDA and SCL pins directly
|
|
TWCR &= ~(_BV(TWEN));
|
|
#endif
|
|
|
|
// Make SDA (data) and SCL (clock) pins inputs with pullup
|
|
pinMode(sda, INPUT_PULLUP);
|
|
pinMode(scl, INPUT_PULLUP);
|
|
|
|
nice_delay(2500);
|
|
// Wait 2.5 secs. This is strictly only necessary on the first power
|
|
// up of the DS3231 module to allow it to initialize properly,
|
|
// but is also assists in reliable programming of FioV3 boards as it gives the
|
|
// IDE a chance to start uploaded the program
|
|
// before existing sketch confuses the IDE by sending Serial data.
|
|
|
|
// If it is held low the device cannot become the I2C master
|
|
// I2C bus error. Could not clear SCL clock line held low
|
|
boolean scl_low = (digitalRead(scl) == LOW);
|
|
if (scl_low) return 1;
|
|
|
|
|
|
boolean sda_low = (digitalRead(sda) == LOW);
|
|
int clockCount = 20; // > 2x9 clock
|
|
|
|
// While SDA is low for at most 20 cycles
|
|
while (sda_low && (clockCount > 0)) {
|
|
|
|
clockCount--;
|
|
|
|
// Note: I2C bus is open collector so do NOT drive SCL or SDA high
|
|
pinMode(scl, INPUT); // release SCL pullup so that when made output it will be LOW
|
|
pinMode(scl, OUTPUT); // then clock SCL Low
|
|
delayMicroseconds(10); // for >5uS
|
|
pinMode(scl, INPUT); // release SCL LOW
|
|
pinMode(scl, INPUT_PULLUP); // turn on pullup resistors again
|
|
// do not force high as slave may be holding it low for clock stretching
|
|
|
|
delayMicroseconds(10); // The >5uS is so that even the slowest I2C devices are handled
|
|
|
|
// loop waiting for SCL to become high only wait 2sec
|
|
scl_low = (digitalRead(scl) == LOW);
|
|
int counter = 20;
|
|
while (scl_low && (counter > 0)) {
|
|
counter--;
|
|
nice_delay(100);
|
|
scl_low = (digitalRead(scl) == LOW);
|
|
}
|
|
|
|
// If still low after 2 sec error
|
|
// I2C bus error. Could not clear. SCL clock line held low by slave clock stretch for >2sec
|
|
if (scl_low) return 2;
|
|
|
|
sda_low = (digitalRead(sda) == LOW); // and check SDA input again and loop
|
|
|
|
}
|
|
|
|
// If still low
|
|
// I2C bus error. Could not clear. SDA data line held low
|
|
if (sda_low) return 3;
|
|
|
|
// Pull SDA line low for "start" or "repeated start"
|
|
pinMode(sda, INPUT); // remove pullup
|
|
pinMode(sda, OUTPUT); // and then make it LOW i.e. send an I2C Start or Repeated start control
|
|
|
|
// When there is only one I2C master a "start" or "repeat start" has the same function as a "stop" and clears the bus
|
|
// A Repeat Start is a Start occurring after a Start with no intervening Stop.
|
|
|
|
delayMicroseconds(10); // wait >5uS
|
|
pinMode(sda, INPUT); // remove output low
|
|
pinMode(sda, INPUT_PULLUP); // and make SDA high i.e. send I2C STOP control.
|
|
|
|
delayMicroseconds(10); // wait >5uS
|
|
pinMode(sda, INPUT); // and reset pins as tri-state inputs which is the default state on reset
|
|
pinMode(scl, INPUT);
|
|
|
|
// Everything OK
|
|
return 0;
|
|
|
|
}
|
|
|
|
#if WEB_SUPPORT
|
|
|
|
bool _i2cWebSocketOnReceive(const char * key, JsonVariant& value) {
|
|
return (strncmp(key, "i2c", 3) == 0);
|
|
}
|
|
|
|
#endif // WEB_SUPPORT
|
|
// ---------------------------------------------------------------------
|
|
// I2C API
|
|
// ---------------------------------------------------------------------
|
|
|
|
#if I2C_USE_BRZO
|
|
|
|
void i2c_wakeup(uint8_t address) {
|
|
brzo_i2c_start_transaction(_address, _i2c_scl_frequency);
|
|
brzo_i2c_end_transaction();
|
|
}
|
|
|
|
uint8_t i2c_write_uint8(uint8_t address, uint8_t value) {
|
|
uint8_t buffer[1] = {value};
|
|
brzo_i2c_start_transaction(_address, _i2c_scl_frequency);
|
|
brzo_i2c_write_uint8(buffer, 1, false);
|
|
return brzo_i2c_end_transaction();
|
|
}
|
|
|
|
uint8_t i2c_write_buffer(uint8_t address, uint8_t * buffer, size_t len) {
|
|
brzo_i2c_start_transaction(_address, _i2c_scl_frequency);
|
|
brzo_i2c_write_uint8(buffer, len, false);
|
|
return brzo_i2c_end_transaction();
|
|
}
|
|
|
|
uint8_t i2c_read_uint8(uint8_t address) {
|
|
uint8_t buffer[1] = {reg};
|
|
brzo_i2c_start_transaction(_address, _i2c_scl_frequency);
|
|
brzo_i2c_read(buffer, 1, false);
|
|
brzo_i2c_end_transaction();
|
|
return buffer[0];
|
|
};
|
|
|
|
uint8_t i2c_read_uint8(uint8_t address, uint8_t reg) {
|
|
uint8_t buffer[1] = {reg};
|
|
brzo_i2c_start_transaction(_address, _i2c_scl_frequency);
|
|
brzo_i2c_write_uint8(buffer, 1, false);
|
|
brzo_i2c_read(buffer, 1, false);
|
|
brzo_i2c_end_transaction();
|
|
return buffer[0];
|
|
};
|
|
|
|
uint16_t i2c_read_uint16(uint8_t address) {
|
|
uint8_t buffer[2] = {reg, 0};
|
|
brzo_i2c_start_transaction(_address, _i2c_scl_frequency);
|
|
brzo_i2c_read(buffer, 2, false);
|
|
brzo_i2c_end_transaction();
|
|
return (buffer[0] * 256) | buffer[1];
|
|
};
|
|
|
|
uint16_t i2c_read_uint16(uint8_t address, uint8_t reg) {
|
|
uint8_t buffer[2] = {reg, 0};
|
|
brzo_i2c_start_transaction(_address, _i2c_scl_frequency);
|
|
brzo_i2c_write_uint8(buffer, 1, false);
|
|
brzo_i2c_read(buffer, 2, false);
|
|
brzo_i2c_end_transaction();
|
|
return (buffer[0] * 256) | buffer[1];
|
|
};
|
|
|
|
void i2c_read_buffer(uint8_t address, uint8_t * buffer, size_t len) {
|
|
brzo_i2c_start_transaction(address, _i2c_scl_frequency);
|
|
brzo_i2c_read(buffer, len, false);
|
|
brzo_i2c_end_transaction();
|
|
}
|
|
|
|
#else // not I2C_USE_BRZO
|
|
|
|
void i2c_wakeup(uint8_t address) {
|
|
Wire.beginTransmission((uint8_t) address);
|
|
Wire.endTransmission();
|
|
}
|
|
|
|
uint8_t i2c_write_uint8(uint8_t address, uint8_t value) {
|
|
Wire.beginTransmission((uint8_t) address);
|
|
Wire.write((uint8_t) value);
|
|
return Wire.endTransmission();
|
|
}
|
|
|
|
uint8_t i2c_write_buffer(uint8_t address, uint8_t * buffer, size_t len) {
|
|
Wire.beginTransmission((uint8_t) address);
|
|
Wire.write(buffer, len);
|
|
return Wire.endTransmission();
|
|
}
|
|
|
|
uint8_t i2c_read_uint8(uint8_t address) {
|
|
uint8_t value;
|
|
Wire.beginTransmission((uint8_t) address);
|
|
Wire.requestFrom((uint8_t) address, (uint8_t) 1);
|
|
value = Wire.read();
|
|
Wire.endTransmission();
|
|
return value;
|
|
};
|
|
|
|
uint8_t i2c_read_uint8(uint8_t address, uint8_t reg) {
|
|
uint8_t value;
|
|
Wire.beginTransmission((uint8_t) address);
|
|
Wire.write((uint8_t) reg);
|
|
Wire.endTransmission();
|
|
Wire.requestFrom((uint8_t) address, (uint8_t) 1);
|
|
value = Wire.read();
|
|
Wire.endTransmission();
|
|
return value;
|
|
};
|
|
|
|
uint16_t i2c_read_uint16(uint8_t address) {
|
|
uint16_t value;
|
|
Wire.beginTransmission((uint8_t) address);
|
|
Wire.requestFrom((uint8_t) address, (uint8_t) 2);
|
|
value = (Wire.read() * 256) | Wire.read();
|
|
Wire.endTransmission();
|
|
return value;
|
|
};
|
|
|
|
uint16_t i2c_read_uint16(uint8_t address, uint8_t reg) {
|
|
uint16_t value;
|
|
Wire.beginTransmission((uint8_t) address);
|
|
Wire.write((uint8_t) reg);
|
|
Wire.endTransmission();
|
|
Wire.requestFrom((uint8_t) address, (uint8_t) 2);
|
|
value = (Wire.read() * 256) | Wire.read();
|
|
Wire.endTransmission();
|
|
return value;
|
|
};
|
|
|
|
void i2c_read_buffer(uint8_t address, uint8_t * buffer, size_t len) {
|
|
Wire.beginTransmission((uint8_t) address);
|
|
Wire.requestFrom(address, (uint8_t) len);
|
|
for (int i=0; i<len; i++) buffer[i] = Wire.read();
|
|
Wire.endTransmission();
|
|
}
|
|
|
|
#endif // I2C_USE_BRZO
|
|
|
|
uint8_t i2c_write_uint8(uint8_t address, uint8_t reg, uint8_t value) {
|
|
uint8_t buffer[2] = {reg, value};
|
|
return i2c_write_buffer(address, buffer, 2);
|
|
}
|
|
|
|
uint8_t i2c_write_uint8(uint8_t address, uint8_t reg, uint8_t value1, uint8_t value2) {
|
|
uint8_t buffer[3] = {reg, value1, value2};
|
|
return i2c_write_buffer(address, buffer, 3);
|
|
}
|
|
|
|
uint8_t i2c_write_uint16(uint8_t address, uint8_t reg, uint16_t value) {
|
|
uint8_t buffer[3];
|
|
buffer[0] = reg;
|
|
buffer[1] = (value >> 8) & 0xFF;
|
|
buffer[2] = (value >> 0) & 0xFF;
|
|
return i2c_write_buffer(address, buffer, 3);
|
|
}
|
|
|
|
uint8_t i2c_write_uint16(uint8_t address, uint16_t value) {
|
|
uint8_t buffer[2];
|
|
buffer[0] = (value >> 8) & 0xFF;
|
|
buffer[1] = (value >> 0) & 0xFF;
|
|
return i2c_write_buffer(address, buffer, 2);
|
|
}
|
|
|
|
uint16_t i2c_read_uint16_le(uint8_t address, uint8_t reg) {
|
|
uint16_t temp = i2c_read_uint16(address, reg);
|
|
return (temp / 256) | (temp * 256);
|
|
};
|
|
|
|
int16_t i2c_read_int16(uint8_t address, uint8_t reg) {
|
|
return (int16_t) i2c_read_uint16(address, reg);
|
|
};
|
|
|
|
int16_t i2c_read_int16_le(uint8_t address, uint8_t reg) {
|
|
return (int16_t) i2c_read_uint16_le(address, reg);
|
|
};
|
|
|
|
// -----------------------------------------------------------------------------
|
|
// Utils
|
|
// -----------------------------------------------------------------------------
|
|
|
|
void i2cClearBus() {
|
|
unsigned char sda = getSetting("i2cSDA", I2C_SDA_PIN).toInt();
|
|
unsigned char scl = getSetting("i2cSCL", I2C_SCL_PIN).toInt();
|
|
DEBUG_MSG_P(PSTR("[I2C] Clear bus (response: %d)\n"), _i2cClearbus(sda, scl));
|
|
}
|
|
|
|
bool i2cCheck(unsigned char address) {
|
|
#if I2C_USE_BRZO
|
|
brzo_i2c_start_transaction(address, _i2c_scl_frequency);
|
|
brzo_i2c_ACK_polling(1000);
|
|
return brzo_i2c_end_transaction();
|
|
#else
|
|
Wire.beginTransmission(address);
|
|
return Wire.endTransmission();
|
|
#endif
|
|
}
|
|
|
|
bool i2cGetLock(unsigned char address) {
|
|
unsigned char index = address / 8;
|
|
unsigned char mask = 1 << (address % 8);
|
|
if (_i2c_locked[index] & mask) return false;
|
|
_i2c_locked[index] = _i2c_locked[index] | mask;
|
|
DEBUG_MSG_P(PSTR("[I2C] Address 0x%02X locked\n"), address);
|
|
return true;
|
|
}
|
|
|
|
bool i2cReleaseLock(unsigned char address) {
|
|
unsigned char index = address / 8;
|
|
unsigned char mask = 1 << (address % 8);
|
|
if (_i2c_locked[index] & mask) {
|
|
_i2c_locked[index] = _i2c_locked[index] & ~mask;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
unsigned char i2cFind(size_t size, unsigned char * addresses, unsigned char &start) {
|
|
for (unsigned char i=start; i<size; i++) {
|
|
if (i2cCheck(addresses[i]) == 0) {
|
|
start = i;
|
|
return addresses[i];
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
unsigned char i2cFind(size_t size, unsigned char * addresses) {
|
|
unsigned char start = 0;
|
|
return i2cFind(size, addresses, start);
|
|
}
|
|
|
|
unsigned char i2cFindAndLock(size_t size, unsigned char * addresses) {
|
|
unsigned char start = 0;
|
|
unsigned char address = 0;
|
|
while (address = i2cFind(size, addresses, start)) {
|
|
if (i2cGetLock(address)) break;
|
|
start++;
|
|
}
|
|
return address;
|
|
}
|
|
|
|
void i2cScan() {
|
|
unsigned char nDevices = 0;
|
|
for (unsigned char address = 1; address < 127; address++) {
|
|
unsigned char error = i2cCheck(address);
|
|
if (error == 0) {
|
|
DEBUG_MSG_P(PSTR("[I2C] Device found at address 0x%02X\n"), address);
|
|
nDevices++;
|
|
}
|
|
}
|
|
if (nDevices == 0) DEBUG_MSG_P(PSTR("[I2C] No devices found\n"));
|
|
}
|
|
|
|
void i2cSetup() {
|
|
|
|
unsigned char sda = getSetting("i2cSDA", I2C_SDA_PIN).toInt();
|
|
unsigned char scl = getSetting("i2cSCL", I2C_SCL_PIN).toInt();
|
|
|
|
#if I2C_USE_BRZO
|
|
unsigned long cst = getSetting("i2cCST", I2C_CLOCK_STRETCH_TIME).toInt();
|
|
_i2c_scl_frequency = getSetting("i2cFreq", I2C_SCL_FREQUENCY).toInt();
|
|
brzo_i2c_setup(sda, scl, cst);
|
|
#else
|
|
Wire.begin(sda, scl);
|
|
#endif
|
|
|
|
#if WEB_SUPPORT
|
|
wsOnReceiveRegister(_i2cWebSocketOnReceive);
|
|
#endif
|
|
|
|
DEBUG_MSG_P(PSTR("[I2C] Using GPIO%u for SDA and GPIO%u for SCL\n"), sda, scl);
|
|
|
|
#if I2C_CLEAR_BUS
|
|
i2cClearBus();
|
|
#endif
|
|
|
|
#if I2C_PERFORM_SCAN
|
|
i2cScan();
|
|
#endif
|
|
|
|
}
|
|
|
|
#endif
|