Revision 0:0a76ae27065b, committed 2010-05-05

Comitter:

Clemo

Date:

Wed May 05 12:10:15 2010 +0000

Commit message:

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/accelerometer.cpp	Wed May 05 12:10:15 2010 +0000
@@ -0,0 +1,52 @@
+/*
+Accelerometer driver.
+
+CPV, 4/9/2009
+*/
+
+#include "accelerometer.h"
+
+
+void Accelerometer1D::initialise(PinName pin, int tau, int offset)
+{
+  m_pin = pin;
+  m_offset = offset;
+  m_filter.initialise(tau);
+}
+
+
+//===============================================
+
+
+Accelerometer2D::Accelerometer2D(PinName ch0, PinName ch1, int tau, int offset)
+{
+  m_channels[0].initialise(ch0,tau,offset);
+  m_channels[1].initialise(ch1,tau,offset);
+}
+
+
+void Accelerometer2D::tick(void)
+{
+  m_channels[0].tick();
+  m_channels[1].tick();
+}
+
+
+//===============================================
+
+
+Accelerometer3D::Accelerometer3D(PinName ch0, PinName ch1, PinName ch2, int tau, int offset)
+{
+  m_channels[0].initialise(ch0,tau,offset);
+  m_channels[1].initialise(ch1,tau,offset);
+  m_channels[2].initialise(ch2,tau,offset);
+}
+
+
+void Accelerometer3D::tick(void)
+{
+  m_channels[0].tick();
+  m_channels[1].tick();
+  m_channels[2].tick();
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/accelerometer.h	Wed May 05 12:10:15 2010 +0000
@@ -0,0 +1,54 @@
+/*
+Accelerometer driver.
+
+CPV, 4/9/2009
+*/
+
+#ifndef __ACCELEROMETER_H__
+#define __ACCELEROMETER_H__
+
+
+#include "mbed.h"
+#include "filters.h"
+
+
+class Accelerometer1D
+{
+public:
+  void initialise(PinName pin, int tau, int offset=0xffff>>1);
+  void tick(void) { m_filter.tick((int)AnalogIn(m_pin).read_u16()&0xfff0); }
+  int operator()(void) { return m_filter() - m_offset; }
+  int read(void) { return m_filter() - m_offset; }
+
+protected:
+  FilterIirI m_filter;
+  PinName m_pin;
+  int m_offset;
+};
+
+
+class Accelerometer2D
+{
+public:
+  Accelerometer2D(PinName ch0, PinName ch1, int tau, int offset=0xffff>>1);
+  void tick(void);
+  int read(int ch) { return m_channels[ch].read(); }
+
+protected:
+  Accelerometer1D m_channels[2];
+};
+
+
+class Accelerometer3D
+{
+public:
+  Accelerometer3D(PinName ch0, PinName ch1, PinName ch2, int tau, int offset=0xffff>>1);
+  void tick(void);
+  int read(int ch) { return m_channels[ch].read(); }
+
+protected:
+  Accelerometer1D m_channels[3];
+};
+
+
+#endif // __ACCELEROMETER_H__

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/filters.cpp	Wed May 05 12:10:15 2010 +0000
@@ -0,0 +1,84 @@
+/*
+mbed touchpad & accelerometer experiments.
+
+CPV, 14/09/2009
+*/
+
+
+#include <string.h>
+#include "filters.h"
+
+
+void FilterBoxF::initialise(unsigned int size)
+{
+  m_size = size;
+  if (m_size>FILTER_MAX_SIZE) m_size = FILTER_MAX_SIZE;
+  memset(m_history,0,sizeof(float)*FILTER_MAX_SIZE);
+  m_index = 0;
+  m_out = 0;
+}
+
+
+float FilterBoxF::tick(float in)
+{
+  m_history[m_index] = in;
+  m_index += 1;
+  if (m_index>=m_size) m_index = 0;
+
+  float sum = 0;
+  for (int i=0; i<m_size; i++)
+  {
+    sum += m_history[i];
+  }
+  m_out = sum/m_size;
+  return m_out;
+}
+
+//=================================
+
+void FilterBoxI::initialise(unsigned int size)
+{
+  m_size = size;
+  if (m_size>FILTER_MAX_SIZE) m_size = FILTER_MAX_SIZE;
+  memset(m_history,0,sizeof(int)*FILTER_MAX_SIZE);
+  m_index = 0;
+  m_out = 0;
+}
+
+
+int FilterBoxI::tick(int in)
+{
+  m_history[m_index] = in;
+  m_index += 1;
+  if (m_index>=m_size) m_index = 0;
+
+  int sum = 0;
+  for (int i=0; i<m_size; i++)
+  {
+    sum += m_history[i];
+  }
+  m_out = sum/m_size;
+  return m_out;
+}
+
+//=================================
+
+void FilterIirI::initialise(int tau, int limit)
+{
+  m_tau = tau;
+  m_limit = limit;
+  m_remainder = 0;
+  m_out = 0;
+}
+
+
+int FilterIirI::tick(int in)
+{
+  int temp = in - m_out + m_remainder;
+  m_remainder = temp % m_tau;
+  m_out += temp / m_tau;
+  if (m_out>m_limit) m_out = m_limit;
+  if (m_out<-m_limit) m_out = -m_limit;
+  return m_out;
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/filters.h	Wed May 05 12:10:15 2010 +0000
@@ -0,0 +1,62 @@
+/*
+mbed touchpad & accelerometer experiments.
+
+CPV, 14/09/2009
+*/
+
+
+#ifndef __FILTERS_H__
+#define __FILTERS_H__
+
+#define FILTER_MAX_SIZE  16
+
+class FilterBoxF
+{
+public:
+  FilterBoxF(void) { initialise(FILTER_MAX_SIZE); }
+  void initialise(unsigned int size);
+  float tick(float in);
+  float get() { return m_out; }
+  float operator()(void) { return m_out; }
+  
+protected:
+  float m_history[FILTER_MAX_SIZE];
+  unsigned int m_size;
+  unsigned int m_index;
+  float m_out;
+};
+
+
+class FilterBoxI
+{
+public:
+  FilterBoxI(void) { initialise(FILTER_MAX_SIZE); }
+  void initialise(unsigned int size);
+  int tick(int in);
+  int operator()(void) { return m_out; }
+  
+protected:
+  int m_history[FILTER_MAX_SIZE];
+  unsigned int m_size;
+  unsigned int m_index;
+  int m_out;
+};
+
+
+class FilterIirI
+{
+public:
+  FilterIirI(void) { initialise(); }
+  void initialise(int tau=1, int limit=0xffff);
+  int tick(int in);
+  int operator()(void) { return m_out; }
+  
+protected:
+  int m_out;
+  int m_remainder;
+  int m_limit;
+  int m_tau;
+};
+
+
+#endif // __FILTERS_H__

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed May 05 12:10:15 2010 +0000
@@ -0,0 +1,123 @@
+/*
+mbed touchpad & accelerometer experiments.
+
+CPV, 14/09/2009
+*/
+
+#include "mbed.h"
+#include "touchpad.h"
+#include "accelerometer.h"
+#include "my_pwm_out.h"
+
+
+// Pin definitions.
+#define ACC0  p20
+#define ACC1  p19
+#define X0  p18
+#define Y0  p17
+#define X1  p16
+#define Y1  p15
+
+
+// Some global objects.
+DigitalOut led1(LED1);
+Ticker timer1; // Sample clock.
+Ticker timer2; // "keyboard" scan clock.
+Ticker timer3; // LED clock.
+Touchpad tp(X0,X1,Y0,Y1);
+Accelerometer2D acc(ACC0,ACC1,10);
+MyPwmOut buzzer(p21); // Subclassed from PwmOut.
+
+
+float DutyCycle = 0.0; // No sound.
+int Period = 1136; // in us => 880 Hz.
+int FlagUpdateSound = 0;
+
+// Periods in us.
+const int freq[4][6] = 
+{
+  { 1607, 1517, 1432, 1351, 1276, 1204 },
+  { 1136, 1073, 1012, 956, 902, 851 },
+  { 804, 758, 716, 676, 638, 602 },
+  { 568, 536, 506, 478, 451, 426 },
+};
+
+
+void sample(void)
+{
+  tp.tick();
+  acc.tick();
+}
+
+
+void scan_keyboard(void)
+{
+  if (tp.hotspot()>0)
+  {
+    int x = tp.get_hotspot_x();
+    int y = tp.get_hotspot_y();
+    Period = freq[y][x]*(1.0+acc.read(0)/64000.0);
+    DutyCycle = 0.5 + acc.read(1)/32000.0;
+    FlagUpdateSound = 1;
+  }
+  else
+  {
+    if (DutyCycle!=0.0) 
+    {
+      DutyCycle = 0.0;
+      FlagUpdateSound = 1;
+    }
+  }
+}
+
+
+void toggle_led(void)
+{
+  if (led1==1) led1 = 0;
+  else led1 = 1;
+}
+
+
+int main() 
+{
+  printf("\n");
+  printf("-=o Touch, Shake & Whine o=-\n");
+  printf("\n");
+  printf("mbed touchpad & 2D accelerometer demo\n");
+  printf("\n");
+  printf("A buzzer is driven by a PWM signal to generate musical notes.\n");
+  printf("A touchpad is used as a keypad, divided in a 6 by 4 matrix.\n");
+  printf("The position on the touchpad determines the note played by the\n");
+  printf("buzzer. A 2-axis accelerometer is used to modulate the frequency\n");
+  printf("and the duty-cycle of the PWM signal.\n");
+  printf("A blinking LED shows that the system is running.\n");
+  printf("\n");
+  printf("Touch & shake the circuit to make it whine.\n");
+  printf("\n");
+  printf("Demonstrates:\n");
+  printf("- the use of a resistive touchpad\n");
+  printf("- the use of a 2D accelerometer\n");
+  printf("- the use of PWM for smooth frequency generation\n");
+  printf("- on-the-fly pin function switching\n");
+  printf("- mbed \"base\" class extension\n");
+  printf("\n");
+  printf("CPV, 14/09/2009\n");
+  printf("\n");
+  printf("     -end-\n\n");
+  
+  led1 = 1; // LED on.
+  
+  timer1.attach_us(&sample,1000); // Sample every 1 ms.
+  timer2.attach_us(&scan_keyboard,10000); // Scan the touchpad every 10 ms.
+  timer3.attach_us(&toggle_led,500000); // Toggle the LED every 500 ms.
+
+  while (1)
+  {
+    if (FlagUpdateSound==1)
+    {
+      // Only update period & duty-cycle when new data is available.
+      FlagUpdateSound = 0;
+      buzzer.set(Period/1000000.0,DutyCycle);
+    }
+  }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Wed May 05 12:10:15 2010 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/f63353af7be8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/my_pwm_out.cpp	Wed May 05 12:10:15 2010 +0000
@@ -0,0 +1,56 @@
+/*
+mbed touchpad & accelerometer experiments.
+
+CPV, 14/09/2009
+*/
+
+
+#include "my_pwm_out.h"
+
+
+using namespace mbed;
+
+
+MyPwmOut::MyPwmOut(PinName pin, const char *name) : PwmOut(pin,name)
+{
+  m_channel = (pin&0x0000001f) + 1; // Between 1 and 6.
+  m_p_mrx = (uint32_t *)&LPC_PWM1->MR0 + m_channel; // Select MRx register for this channel.
+  if (m_channel>=4) m_p_mrx += 6; // Skip CR registers if needed.
+  m_pclk = get_pclk();
+}
+
+
+float MyPwmOut::get_pclk(void)
+{
+  float Fin = 12000000; // From the mbed schematic.
+  uint32_t m = 1 + (LPC_SC->PLL0STAT&0x00007fff);
+  uint32_t n = 1 + ((LPC_SC->PLL0STAT&0x00ff0000)>>16);
+  float Fcco = 2*m*Fin/n; // PLL frequency.
+  float cclk = Fcco/(1+(LPC_SC->CCLKCFG&0x000000ff)); // Get CCLK from Fcco.
+
+  m_pclk = cclk/4;
+  switch ((LPC_SC->PCLKSEL0&0x00003000)>>12)
+  {
+    case 0: m_pclk = cclk/4; break;
+    case 1: m_pclk = cclk; break;
+    case 2: m_pclk = cclk/2; break;
+    case 3: m_pclk = cclk/8; break;
+  }
+
+  //printf("Fin = %0.0f\n",Fin);
+  //printf("m = %d, n = %d\n",m,n);
+  //printf("Fcco = %0.0f\n",Fcco);
+  //printf("CLKC = %0.0f\n",cclk);
+  //printf("PLCK = %0.0f\n",m_pclk);
+  
+  return m_pclk;
+}
+
+
+void MyPwmOut::set(float period, float duty_cycle)
+{
+  LPC_PWM1->MR0 = period*m_pclk; // Set new period in seconds.
+  *m_p_mrx = duty_cycle * LPC_PWM1->MR0; // Set new duty-cycle.
+  LPC_PWM1->LER |= (1<<m_channel)|1; // Use MRx & MR0 value on next TC reset.
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/my_pwm_out.h	Wed May 05 12:10:15 2010 +0000
@@ -0,0 +1,51 @@
+/*
+mbed touchpad & accelerometer experiments.
+
+CPV, 14/09/2009
+*/
+
+
+#ifndef __MY_PWM_OUT_H__
+#define __MY_PWM_OUT_H__
+
+
+#include "PwmOut.h"
+namespace mbed
+{
+
+class MyPwmOut : public PwmOut
+{
+public:
+  /* Constructor: PwmOut
+   *  Create a PwmOut connected to the specified pin
+   *
+   * Variables:
+   *  pin - PwmOut pin to connect to
+   */
+  MyPwmOut(PinName pin, const char *name = NULL);
+  
+  /* Function: set
+   *  Set the PWM period, specified in seconds (float)
+   *  and the ouput duty-cycle, specified as a percentage (float)
+   *
+   * Variables:
+   *  period - A floating-point value representing the output period, 
+   *    specified in seconds.
+   *  duty_cycle - A floating-point value representing the output duty-cycle, 
+   *    specified as a percentage. The value should lie between
+   *    0.0f (representing on 0%) and 1.0f (representing on 100%).
+   *    Values outside this range will be saturated to 0.0f or 1.0f.     
+   */
+  void set(float period, float duty_cycle);
+  
+  float get_pclk(void);
+
+protected:
+  float m_pclk;
+  uint32_t m_channel;
+  uint32_t *m_p_mrx;
+};
+
+} // namespace mbed
+
+#endif // __MY_PWM_OUT_H__

--- /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());
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/touchpad.h	Wed May 05 12:10:15 2010 +0000
@@ -0,0 +1,61 @@
+/*
+Touchpad driver.
+
+CPV, 3/9/2009
+*/
+
+#ifndef __TOUCHPAD_H__
+#define __TOUCHPAD_H__
+
+
+#include "mbed.h"
+#include "filters.h"
+
+
+class TouchpadChannel
+{
+public:
+  void initialise(int min, int quantise_step);
+  void tick(int v) { m_filter.tick(v); }
+  int quantise(void);
+  int operator()(void) { return m_quantised; }
+  int get_raw(void) { return m_filter(); }
+
+protected:
+  FilterBoxI m_filter;
+  int m_min;
+  int m_quantise_step;
+  int m_quantised;
+};
+
+
+class Touchpad
+{
+public:
+  Touchpad(PinName x0, PinName x1, PinName y0, PinName y1);
+  
+  void tick(void);
+  
+  int get_raw_x(void) { return m_ch_x.get_raw(); }
+  int get_raw_y(void) { return m_ch_y.get_raw(); }
+  
+  int hotspot(void) { return (m_ch_x.quantise()>=0 && m_ch_y.quantise()>=0); }
+  int get_hotspot_x(void) { return m_ch_x(); }
+  int get_hotspot_y(void) { return m_ch_y(); }
+
+protected:
+  TouchpadChannel m_ch_x;
+  TouchpadChannel m_ch_y;
+
+  PinName m_x0;
+  PinName m_x1;
+  PinName m_y0;
+  PinName m_y1;
+
+  int read(PinName drive_hi, PinName drive_lo, PinName read_hi, PinName read_lo);
+  int read_x(void) { return read(m_x1,m_x0,m_y1,m_y0); }
+  int read_y(void) { return read(m_y1,m_y0,m_x1,m_x0); }
+};
+
+
+#endif // __TOUCHPAD_H__