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);
  } elseif(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_tstartAt=millis();
 while(1){
+//have been looping for too long
+if((millis() -startAt)>50){
+//log_e("Timeout! Addr: %x", address >> 1);
+I2C_MUTEX_UNLOCK();
+returnI2C_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();
 returnI2C_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;
- } elseif(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_tstartAt=millis();
 while(1){
+//have been looping for too long
+if((millis() -startAt)>50){
+//log_e("Timeout! Addr: %x", address >> 1);
+I2C_MUTEX_UNLOCK();
+returnI2C_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();
 returnI2C_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;
- } elseif(i2c->dev->command[cmdIdx-1].done){
+
+if(i2c->dev->command[cmdIdx-1].done){
 break;
  }
  }
 
 inti=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_ti2cSetFrequency(i2c_t*i2c, uint32_tclk_speed)
 {
-uint32_tperiod= (APB_CLK_FREQ/clk_speed) / 2;
-
 if(i2c==NULL){
 returnI2C_ERROR_DEV;
  }
 
+uint32_tperiod= (APB_CLK_FREQ/clk_speed) / 2;
+uint32_thalfPeriod=period/2;
+uint32_tquarterPeriod=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();
 returnI2C_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)
 returni2c;
 }
 
-
+voidi2cInitFix(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_ti2c_num, uint16_tslave_addr, booladdr_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
+voidi2cInitFix(i2c_t*i2c);
+
 i2c_err_ti2cSetFrequency(i2c_t*i2c, uint32_tclk_speed);
 uint32_ti2cGetFrequency(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);
 }
 
 voidTwoWire::setClock(uint32_t frequency)