Diff: touchpad.cpp

Revision:

0:0a76ae27065b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/touchpad.cpp	Wed May 05 12:10:15 2010 +0000
@@ -0,0 +1,66 @@
+/*
+Touchpad driver.
+
+CPV, 3/9/2009
+*/
+
+#include "touchpad.h"
+
+
+void TouchpadChannel::initialise(int min, int quantise_step)
+{
+  m_min = min;
+  m_quantise_step = quantise_step;
+  m_filter.initialise(8);
+  m_quantised = -1;
+}
+
+
+int TouchpadChannel::quantise(void)
+{
+  m_quantised = -1;
+  int raw = m_filter();
+  if (raw>m_min)
+  {
+    m_quantised = 0;
+    while(raw>m_quantise_step)
+    {
+      raw -= m_quantise_step;
+      m_quantised += 1;
+    }
+  }
+  return m_quantised;
+}
+
+
+//===============================================
+
+
+Touchpad::Touchpad(PinName x0, PinName x1, PinName y0, PinName y1)
+{
+  m_x0 = x0;
+  m_x1 = x1;
+  m_y0 = y0;
+  m_y1 = y1;
+  m_ch_x.initialise(0.1*0xffff,0.16*0xffff);
+  m_ch_y.initialise(0.1*0xffff,0.22*0xffff);
+}
+
+
+int Touchpad::read(PinName drive_hi, PinName drive_lo, PinName read_hi, PinName read_lo)
+{
+  DigitalOut out1(drive_hi);
+  DigitalOut out0(drive_lo);
+  AnalogIn in1(read_hi);
+  AnalogIn in0(read_lo);
+  out0 = 0;
+  out1 = 1;
+  return in1.read_u16();
+}
+
+
+void Touchpad::tick(void)
+{
+  m_ch_x.tick(read_x());
+  m_ch_y.tick(read_y());
+}