at42qt1070: Initial implementation

This module implementes support for the Grove QTouch sensor.

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Zion Orent <zorent@ics.com>
Signed-off-by: John Van Drasek <john.r.van.drasek@intel.com>

src/at42qt1070/at42qt1070.cxx

@@ -0,0 +1,145 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2015 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <unistd.h>
+#include <math.h>
+#include <iostream>
+#include <string>
+
+#include "at42qt1070.h"
+
+using namespace upm;
+using namespace std;
+
+
+AT42QT1070::AT42QT1070(int bus, uint8_t address)
+{
+  m_addr = address;
+
+  // setup our i2c link
+  if ( !(m_i2c = mraa_i2c_init(bus)) )
+    {
+      cerr << __FUNCTION__ << ": mraa_i2c_init() failed." << endl;
+      return;
+    }
+      
+  mraa_result_t rv;
+  
+  if ( (rv = mraa_i2c_address(m_i2c, m_addr)) != MRAA_SUCCESS)
+    {
+      cerr << __FUNCTION__ << ": Could not initialize i2c bus. " << endl;
+      mraa_result_print(rv);
+      return;
+    }
+
+  m_buttonStates = false;
+  m_calibrating = false;
+  m_overflow = false;
+
+}
+
+AT42QT1070::~AT42QT1070()
+{
+  mraa_i2c_stop(m_i2c);
+}
+
+bool AT42QT1070::writeByte(uint8_t reg, uint8_t byte)
+{
+  mraa_result_t rv = mraa_i2c_write_byte_data(m_i2c, byte, reg);
+
+  if (rv != MRAA_SUCCESS)
+    {
+      cerr << __FUNCTION__ << ": mraa_i2c_write_byte() failed." << endl;
+      mraa_result_print(rv);
+      return false;
+    }
+
+  return true;
+}
+
+bool AT42QT1070::writeWord(uint8_t reg, uint16_t word)
+{
+  mraa_result_t rv = mraa_i2c_write_word_data(m_i2c, word, reg);
+
+  if (rv != MRAA_SUCCESS)
+    {
+      cerr << __FUNCTION__ << ": mraa_i2c_write_word() failed." << endl;
+      mraa_result_print(rv);
+      return false;
+    }
+
+  return true;
+}
+
+uint8_t AT42QT1070::readByte(uint8_t reg)
+{
+  return mraa_i2c_read_byte_data(m_i2c, reg);
+}
+
+uint16_t AT42QT1070::readWord(uint8_t reg)
+{
+  return mraa_i2c_read_word_data(m_i2c, reg);
+}
+
+void AT42QT1070::updateState()
+{
+  uint8_t stat = readByte(REG_DETSTATUS);
+
+  // if we are calibrating, don't change anything
+  if (stat & DET_CALIBRATE)
+    {
+      m_calibrating = true;
+      return;
+    }
+  else
+    m_calibrating = false;
+
+  if (stat & DET_OVERFLOW)
+    m_overflow = true;
+  else
+    m_overflow = false;
+
+  // if a touch is occurring, read the button states
+  if (stat & DET_TOUCH)
+    {
+      uint8_t keys = readByte(REG_KEYSTATUS);
+      // high bit is reserved, filter it out
+      m_buttonStates = keys & ~0x80;
+    }
+  else
+    m_buttonStates = 0;
+}
+
+bool AT42QT1070::reset()
+{
+  // write a non-zero value to the reset register
+  return writeByte(REG_RESET, 0xff);
+}
+
+bool AT42QT1070::calibrate()
+{
+  // write a non-zero value to the calibrate register
+  return writeByte(REG_CALIBRATE, 0xff);
+}
+