Hopefully fix I2C/Wire

Tested with (all at the same time): - MPU9250 - HTU21 - TMP102 - BMP180 - AM2320 - SSD1306

Author: me-no-dev

cores/esp32/esp32-hal-i2c.c

@@ -158,6 +158,8 @@ i2c_err_t i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * dat
 
  i2cResetFiFo(i2c);
  i2cResetCmd(i2c);
+ //Clear Interrupts
+ i2c->dev->int_clr.val = 0xFFFFFFFF;
 
  //CMD START
  i2cSetCmd(i2c, 0, I2C_CMD_RSTART, 0, false, false, false);
@@ -174,26 +176,32 @@ i2c_err_t i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * dat
  i = 0;
  while(i<dataSend) {
  i++;
- i2c->dev->fifo_data.data = data[index++];
+ i2c->dev->fifo_data.val = data[index++];
+ while(i2c->dev->status_reg.tx_fifo_cnt < i);
  }
  i2cSetCmd(i2c, 1, I2C_CMD_WRITE, willSend, false, false, true);
  dataLen -= willSend;
 
  //CMD STOP or CMD END if there is more data
- if(dataLen) {
+ if(dataLen || !sendStop) {
  i2cSetCmd(i2c, 2, I2C_CMD_END, 0, false, false, false);
  } else if(sendStop) {
  i2cSetCmd(i2c, 2, I2C_CMD_STOP, 0, false, false, false);
  }
 
- //Clear Interrupts
- i2c->dev->int_clr.val = 0xFFFFFFFF;
-
  //START Transmission
  i2c->dev->ctr.trans_start = 1;
 
  //WAIT Transmission
+ uint32_t startAt = millis();
  while(1) {
+ //have been looping for too long
+ if((millis() - startAt)>50){
+ //log_e("Timeout! Addr: %x", address >> 1);
+ I2C_MUTEX_UNLOCK();
+ return I2C_ERROR_BUS;
+ }
+
  //Bus failed (maybe check for this while waiting?
  if(i2c->dev->int_raw.arbitration_lost) {
  //log_e("Bus Fail! Addr: %x", address >> 1);
@@ -210,14 +218,12 @@ i2c_err_t i2cWrite(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * dat
 
  //Transmission did not finish and ACK_ERR is set
  if(i2c->dev->int_raw.ack_err) {
- //log_e("Ack Error! Addr: %x", address >> 1);
+ //log_w("Ack Error! Addr: %x", address >> 1);
  I2C_MUTEX_UNLOCK();
  return I2C_ERROR_ACK;
  }
 
- if(i2c->dev->ctr.trans_start || i2c->dev->status_reg.bus_busy || !(i2c->dev->int_raw.trans_complete) || !(i2c->dev->command[2].done)) {
- continue;
- } else if(i2c->dev->command[2].done) {
+ if((sendStop && i2c->dev->command[2].done) || !i2c->dev->status_reg.bus_busy){
  break;
  }
  }
@@ -248,9 +254,9 @@ i2c_err_t i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data
  i2cSetCmd(i2c, 0, I2C_CMD_RSTART, 0, false, false, false);
 
  //CMD WRITE ADDRESS
- i2c->dev->fifo_data.data = address & 0xFF;
+ i2c->dev->fifo_data.val = address & 0xFF;
  if(addr_10bit) {
- i2c->dev->fifo_data.data = (address >> 8) & 0xFF;
+ i2c->dev->fifo_data.val = (address >> 8) & 0xFF;
  }
  i2cSetCmd(i2c, 1, I2C_CMD_WRITE, addrLen, false, false, true);
 
@@ -279,7 +285,15 @@ i2c_err_t i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data
  i2c->dev->ctr.trans_start = 1;
 
  //WAIT Transmission
+ uint32_t startAt = millis();
  while(1) {
+ //have been looping for too long
+ if((millis() - startAt)>50){
+ //log_e("Timeout! Addr: %x", address >> 1);
+ I2C_MUTEX_UNLOCK();
+ return I2C_ERROR_BUS;
+ }
+
  //Bus failed (maybe check for this while waiting?
  if(i2c->dev->int_raw.arbitration_lost) {
  //log_e("Bus Fail! Addr: %x", address >> 1);
@@ -296,21 +310,20 @@ i2c_err_t i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data
 
  //Transmission did not finish and ACK_ERR is set
  if(i2c->dev->int_raw.ack_err) {
- //log_e("Ack Error! Addr: %x", address >> 1);
+ //log_w("Ack Error! Addr: %x", address >> 1);
  I2C_MUTEX_UNLOCK();
  return I2C_ERROR_ACK;
  }
- if(i2c->dev->ctr.trans_start || i2c->dev->status_reg.bus_busy || !(i2c->dev->int_raw.trans_complete) || !(i2c->dev->command[cmdIdx-1].done)) {
- continue;
- } else if(i2c->dev->command[cmdIdx-1].done) {
+
+ if(i2c->dev->command[cmdIdx-1].done) {
  break;
  }
  }
 
  int i = 0;
  while(i<willRead) {
  i++;
- data[index++] = i2c->dev->fifo_data.data;
+ data[index++] = i2c->dev->fifo_data.val & 0xFF;
  }
  len -= willRead;
  }
@@ -320,24 +333,34 @@ i2c_err_t i2cRead(i2c_t * i2c, uint16_t address, bool addr_10bit, uint8_t * data
 
 i2c_err_t i2cSetFrequency(i2c_t * i2c, uint32_t clk_speed)
 {
- uint32_t period = (APB_CLK_FREQ/clk_speed) / 2;
-
  if(i2c == NULL){
  return I2C_ERROR_DEV;
  }
 
+ uint32_t period = (APB_CLK_FREQ/clk_speed) / 2;
+ uint32_t halfPeriod = period/2;
+ uint32_t quarterPeriod = period/4;
+
  I2C_MUTEX_LOCK();
+ //the clock num during SCL is low level
  i2c->dev->scl_low_period.scl_low_period = period;
+ //the clock num during SCL is high level
  i2c->dev->scl_high_period.period = period;
 
- i2c->dev->scl_start_hold.time = 50;
- i2c->dev->scl_rstart_setup.time = 50;
+ //the clock num between the negedge of SDA and negedge of SCL for start mark
+ i2c->dev->scl_start_hold.time = halfPeriod;
+ //the clock num between the posedge of SCL and the negedge of SDA for restart mark
+ i2c->dev->scl_rstart_setup.time = halfPeriod;
 
- i2c->dev->scl_stop_hold.time = 50;
- i2c->dev->scl_stop_setup.time = 50;
+ //the clock num after the STOP bit's posedge
+ i2c->dev->scl_stop_hold.time = halfPeriod;
+ //the clock num between the posedge of SCL and the posedge of SDA
+ i2c->dev->scl_stop_setup.time = halfPeriod;
 
- i2c->dev->sda_hold.time = 25;
- i2c->dev->sda_sample.time = 25;
+ //the clock num I2C used to hold the data after the negedge of SCL.
+ i2c->dev->sda_hold.time = quarterPeriod;
+ //the clock num I2C used to sample data on SDA after the posedge of SCL
+ i2c->dev->sda_sample.time = quarterPeriod;
  I2C_MUTEX_UNLOCK();
  return I2C_ERROR_OK;
 }
@@ -389,7 +412,9 @@ i2c_t * i2cInit(uint8_t i2c_num, uint16_t slave_addr, bool addr_10bit_en)
  i2c->dev->ctr.scl_force_out = 1 ;
  i2c->dev->ctr.clk_en = 1;
 
+ //the max clock number of receiving a data
  i2c->dev->timeout.tout = 400000;//clocks max=1048575
+ //disable apb nonfifo access
  i2c->dev->fifo_conf.nonfifo_en = 0;
 
  i2c->dev->slave_addr.val = 0;
@@ -402,4 +427,19 @@ i2c_t * i2cInit(uint8_t i2c_num, uint16_t slave_addr, bool addr_10bit_en)
  return i2c;
 }
 
-
+void i2cInitFix(i2c_t * i2c){
+ if(i2c == NULL){
+ return;
+ }
+ I2C_MUTEX_LOCK();
+ i2cResetFiFo(i2c);
+ i2cResetCmd(i2c);
+ i2c->dev->int_clr.val = 0xFFFFFFFF;
+ i2cSetCmd(i2c, 0, I2C_CMD_RSTART, 0, false, false, false);
+ i2c->dev->fifo_data.data = 0;
+ i2cSetCmd(i2c, 1, I2C_CMD_WRITE, 1, false, false, false);
+ i2cSetCmd(i2c, 2, I2C_CMD_STOP, 0, false, false, false);
+ i2c->dev->ctr.trans_start = 1;
+ while(!i2c->dev->command[2].done);
+ I2C_MUTEX_UNLOCK();
+}

cores/esp32/esp32-hal-i2c.h

@@ -35,6 +35,10 @@ typedef struct i2c_struct_t i2c_t;
 
 i2c_t * i2cInit(uint8_t i2c_num, uint16_t slave_addr, bool addr_10bit_en);
 
+//call this after you setup the bus and pins to send empty packet
+//required because when pins are attached, they emit pulses that lock the bus
+void i2cInitFix(i2c_t * i2c);
+
 i2c_err_t i2cSetFrequency(i2c_t * i2c, uint32_t clk_speed);
 uint32_t i2cGetFrequency(i2c_t * i2c);
 

libraries/Wire/src/Wire.cpp

@@ -86,6 +86,8 @@ void TwoWire::begin(int sdaPin, int sclPin, uint32_t frequency)
  i2cAttachSCL(i2c, scl);
 
  flush();
+
+ i2cInitFix(i2c);
 }
 
 void TwoWire::setClock(uint32_t frequency)