andrewm@268: /*
andrewm@268:  * I2C_MPR121.cpp
andrewm@268:  *
andrewm@268:  *  Created on: Oct 14, 2013
andrewm@268:  *      Author: Victor Zappi
andrewm@268:  */
andrewm@268: 
andrewm@268: 
andrewm@268: #include "I2C_MPR121.h"
andrewm@268: 
andrewm@268: I2C_MPR121::I2C_MPR121() {
andrewm@268: 
andrewm@268: }
andrewm@268: 
andrewm@268: boolean I2C_MPR121::begin(uint8_t bus, uint8_t i2caddr) {
andrewm@268:   _i2c_address = i2caddr;
andrewm@268: 	
andrewm@268:   if(initI2C_RW(bus, i2caddr, 0) > 0)
andrewm@268: 	  return false;
andrewm@268: 
andrewm@268:   // soft reset
andrewm@268:   writeRegister(MPR121_SOFTRESET, 0x63);
andrewm@268:   usleep(1000);
andrewm@268:   //delay(1);
andrewm@268:   for (uint8_t i=0; i<0x7F; i++) {
andrewm@268:   //  Serial.print("$"); Serial.print(i, HEX); 
andrewm@268:   //  Serial.print(": 0x"); Serial.println(readRegister8(i));
andrewm@268:   }
andrewm@268:   
andrewm@268: 
andrewm@268:   writeRegister(MPR121_ECR, 0x0);
andrewm@268: 
andrewm@268:   uint8_t c = readRegister8(MPR121_CONFIG2);
andrewm@268:   
andrewm@268:   if (c != 0x24) {
andrewm@268: 	  rt_printf("MPR121 read 0x%x instead of 0x24\n", c);
andrewm@268: 	  return false;
andrewm@268:   }
andrewm@268: 
andrewm@268:   setThresholds(12, 6);
andrewm@268:   writeRegister(MPR121_MHDR, 0x01);
andrewm@268:   writeRegister(MPR121_NHDR, 0x01);
andrewm@268:   writeRegister(MPR121_NCLR, 0x0E);
andrewm@268:   writeRegister(MPR121_FDLR, 0x00);
andrewm@268: 
andrewm@268:   writeRegister(MPR121_MHDF, 0x01);
andrewm@268:   writeRegister(MPR121_NHDF, 0x05);
andrewm@268:   writeRegister(MPR121_NCLF, 0x01);
andrewm@268:   writeRegister(MPR121_FDLF, 0x00);
andrewm@268: 
andrewm@268:   writeRegister(MPR121_NHDT, 0x00);
andrewm@268:   writeRegister(MPR121_NCLT, 0x00);
andrewm@268:   writeRegister(MPR121_FDLT, 0x00);
andrewm@268: 
andrewm@268:   writeRegister(MPR121_DEBOUNCE, 0);
andrewm@268:   writeRegister(MPR121_CONFIG1, 0x10); // default, 16uA charge current
andrewm@268:   writeRegister(MPR121_CONFIG2, 0x20); // 0.5uS encoding, 1ms period
andrewm@268: 
andrewm@268: //  writeRegister(MPR121_AUTOCONFIG0, 0x8F);
andrewm@268: 
andrewm@268: //  writeRegister(MPR121_UPLIMIT, 150);
andrewm@268: //  writeRegister(MPR121_TARGETLIMIT, 100); // should be ~400 (100 shifted)
andrewm@268: //  writeRegister(MPR121_LOWLIMIT, 50);
andrewm@268:   // enable all electrodes
andrewm@268:   writeRegister(MPR121_ECR, 0x8F);  // start with first 5 bits of baseline tracking
andrewm@268: 
andrewm@268:   return true;
andrewm@268: }
andrewm@268: 
andrewm@268: void I2C_MPR121::setThresholds(uint8_t touch, uint8_t release) {
andrewm@268:   for (uint8_t i=0; i<12; i++) {
andrewm@268:     writeRegister(MPR121_TOUCHTH_0 + 2*i, touch);
andrewm@268:     writeRegister(MPR121_RELEASETH_0 + 2*i, release);
andrewm@268:   }
andrewm@268: }
andrewm@268: 
andrewm@268: uint16_t  I2C_MPR121::filteredData(uint8_t t) {
andrewm@268:   if (t > 12) return 0;
andrewm@268:   return readRegister16(MPR121_FILTDATA_0L + t*2);
andrewm@268: }
andrewm@268: 
andrewm@268: uint16_t  I2C_MPR121::baselineData(uint8_t t) {
andrewm@268:   if (t > 12) return 0;
andrewm@268:   uint16_t bl = readRegister8(MPR121_BASELINE_0 + t);
andrewm@268:   return (bl << 2);
andrewm@268: }
andrewm@268: 
andrewm@268: uint16_t  I2C_MPR121::touched(void) {
andrewm@268:   uint16_t t = readRegister16(MPR121_TOUCHSTATUS_L);
andrewm@268:   return t & 0x0FFF;
andrewm@268: }
andrewm@268: 
andrewm@268: /*********************************************************************/
andrewm@268: 
andrewm@268: 
andrewm@268: uint8_t I2C_MPR121::readRegister8(uint8_t reg) {
andrewm@268:     unsigned char inbuf, outbuf;
andrewm@268:     struct i2c_rdwr_ioctl_data packets;
andrewm@268:     struct i2c_msg messages[2];
andrewm@268: 
andrewm@268:     /*
andrewm@268:      * In order to read a register, we first do a "dummy write" by writing
andrewm@268:      * 0 bytes to the register we want to read from.  This is similar to
andrewm@268:      * the packet in set_i2c_register, except it's 1 byte rather than 2.
andrewm@268:      */
andrewm@268:     outbuf = reg;
andrewm@268:     messages[0].addr  = 0x5A;
andrewm@268:     messages[0].flags = 0;
andrewm@268:     messages[0].len   = sizeof(outbuf);
andrewm@268:     messages[0].buf   = &outbuf;
andrewm@268: 
andrewm@268:     /* The data will get returned in this structure */
andrewm@268:     messages[1].addr  = 0x5A;
andrewm@268:     messages[1].flags = I2C_M_RD/* | I2C_M_NOSTART*/;
andrewm@268:     messages[1].len   = sizeof(inbuf);
andrewm@268:     messages[1].buf   = &inbuf;
andrewm@268: 
andrewm@268:     /* Send the request to the kernel and get the result back */
andrewm@268:     packets.msgs      = messages;
andrewm@268:     packets.nmsgs     = 2;
andrewm@268:     if(ioctl(i2C_file, I2C_RDWR, &packets) < 0) {
andrewm@268:         rt_printf("Unable to send data");
andrewm@268:         return 0;
andrewm@268:     }
andrewm@268: 
andrewm@268:     return inbuf;
andrewm@268: }
andrewm@268: 
andrewm@268: uint16_t I2C_MPR121::readRegister16(uint8_t reg) {
andrewm@268:     unsigned char inbuf[2], outbuf;
andrewm@268:     struct i2c_rdwr_ioctl_data packets;
andrewm@268:     struct i2c_msg messages[2];
andrewm@268: 
andrewm@268:     /*
andrewm@268:      * In order to read a register, we first do a "dummy write" by writing
andrewm@268:      * 0 bytes to the register we want to read from.  This is similar to
andrewm@268:      * the packet in set_i2c_register, except it's 1 byte rather than 2.
andrewm@268:      */
andrewm@268:     outbuf = reg;
andrewm@268:     messages[0].addr  = _i2c_address;
andrewm@268:     messages[0].flags = 0;
andrewm@268:     messages[0].len   = sizeof(outbuf);
andrewm@268:     messages[0].buf   = &outbuf;
andrewm@268: 
andrewm@268:     /* The data will get returned in this structure */
andrewm@268:     messages[1].addr  = _i2c_address;
andrewm@268:     messages[1].flags = I2C_M_RD/* | I2C_M_NOSTART*/;
andrewm@268:     messages[1].len   = sizeof(inbuf);
andrewm@268:     messages[1].buf   = inbuf;
andrewm@268: 
andrewm@268:     /* Send the request to the kernel and get the result back */
andrewm@268:     packets.msgs      = messages;
andrewm@268:     packets.nmsgs     = 2;
andrewm@268:     if(ioctl(i2C_file, I2C_RDWR, &packets) < 0) {
andrewm@268:         rt_printf("Unable to send data");
andrewm@268:         return 0;
andrewm@268:     }
andrewm@268: 
andrewm@268:     return (uint16_t)inbuf[0] | (((uint16_t)inbuf[1]) << 8);
andrewm@268: }
andrewm@268: 
andrewm@268: /**************************************************************************/
andrewm@268: /*!
andrewm@268:     @brief  Writes 8-bits to the specified destination register
andrewm@268: */
andrewm@268: /**************************************************************************/
andrewm@268: void I2C_MPR121::writeRegister(uint8_t reg, uint8_t value) {
andrewm@268: 	uint8_t buf[2] = { reg, value };
andrewm@268: 
andrewm@268: 	if(write(i2C_file, buf, 2) != 2)
andrewm@268: 	{
andrewm@268: 		cout << "Failed to write register " << (int)reg << " on MPR121\n";
andrewm@268: 		return;
andrewm@268: 	}
andrewm@268: }
andrewm@268: