robert@464: /*
robert@464:  * I2C_MPR121.cpp
robert@464:  *
robert@464:  *  Created on: Oct 14, 2013
robert@464:  *      Author: Victor Zappi
robert@464:  */
robert@464: 
robert@464: 
robert@464: #include "I2C_MPR121.h"
robert@464: 
robert@464: I2C_MPR121::I2C_MPR121() {
robert@464: 
robert@464: }
robert@464: 
robert@464: boolean I2C_MPR121::begin(uint8_t bus, uint8_t i2caddr) {
robert@464:   _i2c_address = i2caddr;
robert@464: 	
robert@464:   if(initI2C_RW(bus, i2caddr, 0) > 0)
robert@464: 	  return false;
robert@464: 
robert@464:   // soft reset
robert@464:   writeRegister(MPR121_SOFTRESET, 0x63);
robert@464:   usleep(1000);
robert@464:   //delay(1);
robert@464:   for (uint8_t i=0; i<0x7F; i++) {
robert@464:   //  Serial.print("$"); Serial.print(i, HEX); 
robert@464:   //  Serial.print(": 0x"); Serial.println(readRegister8(i));
robert@464:   }
robert@464:   
robert@464: 
robert@464:   writeRegister(MPR121_ECR, 0x0);
robert@464: 
robert@464:   uint8_t c = readRegister8(MPR121_CONFIG2);
robert@464:   
robert@464:   if (c != 0x24) {
robert@464: 	  rt_printf("MPR121 read 0x%x instead of 0x24\n", c);
robert@464: 	  return false;
robert@464:   }
robert@464: 
robert@464:   setThresholds(12, 6);
robert@464:   writeRegister(MPR121_MHDR, 0x01);
robert@464:   writeRegister(MPR121_NHDR, 0x01);
robert@464:   writeRegister(MPR121_NCLR, 0x0E);
robert@464:   writeRegister(MPR121_FDLR, 0x00);
robert@464: 
robert@464:   writeRegister(MPR121_MHDF, 0x01);
robert@464:   writeRegister(MPR121_NHDF, 0x05);
robert@464:   writeRegister(MPR121_NCLF, 0x01);
robert@464:   writeRegister(MPR121_FDLF, 0x00);
robert@464: 
robert@464:   writeRegister(MPR121_NHDT, 0x00);
robert@464:   writeRegister(MPR121_NCLT, 0x00);
robert@464:   writeRegister(MPR121_FDLT, 0x00);
robert@464: 
robert@464:   writeRegister(MPR121_DEBOUNCE, 0);
robert@464:   writeRegister(MPR121_CONFIG1, 0x10); // default, 16uA charge current
robert@464:   writeRegister(MPR121_CONFIG2, 0x20); // 0.5uS encoding, 1ms period
robert@464: 
robert@464: //  writeRegister(MPR121_AUTOCONFIG0, 0x8F);
robert@464: 
robert@464: //  writeRegister(MPR121_UPLIMIT, 150);
robert@464: //  writeRegister(MPR121_TARGETLIMIT, 100); // should be ~400 (100 shifted)
robert@464: //  writeRegister(MPR121_LOWLIMIT, 50);
robert@464:   // enable all electrodes
robert@464:   writeRegister(MPR121_ECR, 0x8F);  // start with first 5 bits of baseline tracking
robert@464: 
robert@464:   return true;
robert@464: }
robert@464: 
robert@464: void I2C_MPR121::setThresholds(uint8_t touch, uint8_t release) {
robert@464:   for (uint8_t i=0; i<12; i++) {
robert@464:     writeRegister(MPR121_TOUCHTH_0 + 2*i, touch);
robert@464:     writeRegister(MPR121_RELEASETH_0 + 2*i, release);
robert@464:   }
robert@464: }
robert@464: 
robert@464: uint16_t  I2C_MPR121::filteredData(uint8_t t) {
robert@464:   if (t > 12) return 0;
robert@464:   return readRegister16(MPR121_FILTDATA_0L + t*2);
robert@464: }
robert@464: 
robert@464: uint16_t  I2C_MPR121::baselineData(uint8_t t) {
robert@464:   if (t > 12) return 0;
robert@464:   uint16_t bl = readRegister8(MPR121_BASELINE_0 + t);
robert@464:   return (bl << 2);
robert@464: }
robert@464: 
robert@464: uint16_t  I2C_MPR121::touched(void) {
robert@464:   uint16_t t = readRegister16(MPR121_TOUCHSTATUS_L);
robert@464:   return t & 0x0FFF;
robert@464: }
robert@464: 
robert@464: /*********************************************************************/
robert@464: 
robert@464: 
robert@464: uint8_t I2C_MPR121::readRegister8(uint8_t reg) {
robert@464:     unsigned char inbuf, outbuf;
robert@464:     struct i2c_rdwr_ioctl_data packets;
robert@464:     struct i2c_msg messages[2];
robert@464: 
robert@464:     /*
robert@464:      * In order to read a register, we first do a "dummy write" by writing
robert@464:      * 0 bytes to the register we want to read from.  This is similar to
robert@464:      * the packet in set_i2c_register, except it's 1 byte rather than 2.
robert@464:      */
robert@464:     outbuf = reg;
robert@464:     messages[0].addr  = 0x5A;
robert@464:     messages[0].flags = 0;
robert@464:     messages[0].len   = sizeof(outbuf);
robert@464:     messages[0].buf   = &outbuf;
robert@464: 
robert@464:     /* The data will get returned in this structure */
robert@464:     messages[1].addr  = 0x5A;
robert@464:     messages[1].flags = I2C_M_RD/* | I2C_M_NOSTART*/;
robert@464:     messages[1].len   = sizeof(inbuf);
robert@464:     messages[1].buf   = &inbuf;
robert@464: 
robert@464:     /* Send the request to the kernel and get the result back */
robert@464:     packets.msgs      = messages;
robert@464:     packets.nmsgs     = 2;
robert@464:     if(ioctl(i2C_file, I2C_RDWR, &packets) < 0) {
robert@464:         rt_printf("Unable to send data");
robert@464:         return 0;
robert@464:     }
robert@464: 
robert@464:     return inbuf;
robert@464: }
robert@464: 
robert@464: uint16_t I2C_MPR121::readRegister16(uint8_t reg) {
robert@464:     unsigned char inbuf[2], outbuf;
robert@464:     struct i2c_rdwr_ioctl_data packets;
robert@464:     struct i2c_msg messages[2];
robert@464: 
robert@464:     /*
robert@464:      * In order to read a register, we first do a "dummy write" by writing
robert@464:      * 0 bytes to the register we want to read from.  This is similar to
robert@464:      * the packet in set_i2c_register, except it's 1 byte rather than 2.
robert@464:      */
robert@464:     outbuf = reg;
robert@464:     messages[0].addr  = _i2c_address;
robert@464:     messages[0].flags = 0;
robert@464:     messages[0].len   = sizeof(outbuf);
robert@464:     messages[0].buf   = &outbuf;
robert@464: 
robert@464:     /* The data will get returned in this structure */
robert@464:     messages[1].addr  = _i2c_address;
robert@464:     messages[1].flags = I2C_M_RD/* | I2C_M_NOSTART*/;
robert@464:     messages[1].len   = sizeof(inbuf);
robert@464:     messages[1].buf   = inbuf;
robert@464: 
robert@464:     /* Send the request to the kernel and get the result back */
robert@464:     packets.msgs      = messages;
robert@464:     packets.nmsgs     = 2;
robert@464:     if(ioctl(i2C_file, I2C_RDWR, &packets) < 0) {
robert@464:         rt_printf("Unable to send data");
robert@464:         return 0;
robert@464:     }
robert@464: 
robert@464:     return (uint16_t)inbuf[0] | (((uint16_t)inbuf[1]) << 8);
robert@464: }
robert@464: 
robert@464: /**************************************************************************/
robert@464: /*!
robert@464:     @brief  Writes 8-bits to the specified destination register
robert@464: */
robert@464: /**************************************************************************/
robert@464: void I2C_MPR121::writeRegister(uint8_t reg, uint8_t value) {
robert@464: 	uint8_t buf[2] = { reg, value };
robert@464: 
robert@464: 	if(write(i2C_file, buf, 2) != 2)
robert@464: 	{
robert@464: 		cout << "Failed to write register " << (int)reg << " on MPR121\n";
robert@464: 		return;
robert@464: 	}
robert@464: }
robert@464: