Adam Green
Use a Sparkfun Blackberry Trackball Breakout Board as a mouse.
Dependencies: mbed BBTrackball
Revision 0:26bb60735515, committed 2011-12-11
- Comitter:
- AdamGreen
- Date:
- Sun Dec 11 05:38:54 2011 +0000
- Commit message:
- Initial version.
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/BBTrackball.lib Sun Dec 11 05:38:54 2011 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/AdamGreen/code/BBTrackball/#7715a78a7175
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/USBDevice.lib Sun Dec 11 05:38:54 2011 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/samux/code/USBDevice/#f3327d71595f
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/acceleration.cpp Sun Dec 11 05:38:54 2011 +0000
@@ -0,0 +1,141 @@
+/* Copyright 2011 Adam Green (http://mbed.org/users/AdamGreen/)
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+/* Implementation of classes to apply acceleration to input from
+ Sparkfun's Blackberry Trackball Breakout board.
+*/
+#include <mbed.h>
+#include "acceleration.h"
+
+#define ARRAYSIZE(X) (sizeof(X)/sizeof(X[0]))
+
+
+template<size_t SampleCount,
+ int DecelerateThreshold,
+ int AccelerateThreshold,
+ int MaxAcceleration>
+unsigned char CAcceleratedRoller<SampleCount,
+ DecelerateThreshold,
+ AccelerateThreshold,
+ MaxAcceleration>::ClampToUChar(short Value)
+{
+ if (Value < 0)
+ {
+ Value = 0;
+ }
+ else if (Value > 0xFF)
+ {
+ Value = 0xFF;
+ }
+
+ return Value;
+}
+
+
+template<size_t SampleCount,
+ int DecelerateThreshold,
+ int AccelerateThreshold,
+ int MaxAcceleration>
+void CAcceleratedRoller<SampleCount,
+ DecelerateThreshold,
+ AccelerateThreshold,
+ MaxAcceleration>::AccumulateSample(short CurrVelocity)
+{
+ unsigned char ClampedVelocity = ClampToUChar(CurrVelocity);
+
+ // Calculate a running sum over the last SampleCount velocity samples.
+ m_VelocitySum -= m_Samples[m_SampleIndex];
+ m_VelocitySum += ClampedVelocity;
+ m_Samples[m_SampleIndex] = ClampedVelocity;
+
+ m_SampleIndex++;
+ if (m_SampleIndex >= SampleCount)
+ {
+ m_SampleIndex = 0;
+ }
+
+ // As we see a sustained high velocity, increase acceleration and decrease
+ // as the user slows down the velocity.
+ if (m_VelocitySum > AccelerateThreshold && m_Acceleration < MaxAcceleration)
+ {
+ m_Acceleration++;
+ }
+ if (m_VelocitySum < DecelerateThreshold && m_Acceleration > 1)
+ {
+ m_Acceleration--;
+ }
+}
+
+
+
+void CAcceleratedTrackball::UpdateLEDColourBasedOnMotion(int VelocityX,
+ int VelocityY,
+ int ButtonPressed)
+{
+ static const CBBTrackball::SColour RedColour = {255, 0, 0, 0};
+ static const CBBTrackball::SColour GreenColour = { 0, 255, 0, 0};
+ static const CBBTrackball::SColour BlueColour = { 0, 0, 255, 0};
+
+ // If the trackball is being moved then make it green, otherwise leave it
+ // red.
+ if (VelocityX || VelocityY)
+ {
+ m_IterationsSinceLastMotion = 0;
+ SetColour(&GreenColour);
+ }
+ else
+ {
+ if (m_IterationsSinceLastMotion > 250)
+ {
+ SetColour(&RedColour);
+ }
+ else
+ {
+ m_IterationsSinceLastMotion++;
+ }
+ }
+
+ // Switch the button to blue when the button is pressed.
+ if (ButtonPressed)
+ {
+ SetColour(&BlueColour);
+ }
+}
+
+
+void CAcceleratedTrackball::GetState(int& DeltaX, int& DeltaY, int& ButtonPressed)
+{
+ CBBTrackball::SState TrackballState;
+ short VelocityX;
+ short VelocityY;
+
+ CBBTrackball::GetState(&TrackballState);
+
+ m_UpAcceleration.AccumulateSample(TrackballState.Up);
+ m_DownAcceleration.AccumulateSample(TrackballState.Down);
+ m_LeftAcceleration.AccumulateSample(TrackballState.Left);
+ m_RightAcceleration.AccumulateSample(TrackballState.Right);
+
+ // NOTE: The breakout board is rotated 90 degrees on my breadboard.
+ VelocityX = TrackballState.Up * m_UpAcceleration.Acceleration() -
+ TrackballState.Down * m_DownAcceleration.Acceleration();
+ VelocityY = TrackballState.Right * m_RightAcceleration.Acceleration() -
+ TrackballState.Left * m_LeftAcceleration.Acceleration();
+
+ UpdateLEDColourBasedOnMotion(VelocityX, VelocityY, TrackballState.ButtonPressed);
+
+ DeltaX = VelocityX;
+ DeltaY = VelocityY;
+ ButtonPressed = TrackballState.ButtonPressed;
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/acceleration.h Sun Dec 11 05:38:54 2011 +0000
@@ -0,0 +1,97 @@
+/* Copyright 2011 Adam Green (http://mbed.org/users/AdamGreen/)
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+/* Classes to apply acceleration to input from Sparkfun's Blackberry Trackball
+ Breakout board.
+*/
+#ifndef _ACCELERATION_H_
+#define _ACCELERATION_H_
+
+#include <mbed.h>
+#include <limits.h>
+#include "BBTrackball.h"
+
+
+
+/* Class which can apply acceleration to each of the roller inputs from the
+ Sparkfun Blackberry Trackball device.
+*/
+template<size_t SampleCount,
+ int DecelerateThreshold,
+ int AccelerateThreshold,
+ int MaxAcceleration>
+class CAcceleratedRoller
+{
+public:
+ CAcceleratedRoller(void)
+ {
+ m_Acceleration = 1;
+ m_VelocitySum = 0;
+ m_SampleIndex = 0;
+ memset(m_Samples, 0, sizeof(m_Samples));
+ }
+
+ void AccumulateSample(short CurrVelocity);
+ int Acceleration(void) const
+ {
+ return m_Acceleration;
+ }
+
+protected:
+ unsigned char ClampToUChar(short Value);
+ int m_Acceleration;
+ int m_VelocitySum;
+ size_t m_SampleIndex;
+ unsigned char m_Samples[SampleCount];
+};
+
+
+class CAcceleratedTrackball : public CBBTrackball
+{
+public:
+ CAcceleratedTrackball(PinName BluePin,
+ PinName RedPin,
+ PinName GreenPin,
+ PinName WhitePin,
+ PinName UpPin,
+ PinName DownPin,
+ PinName LeftPin,
+ PinName RightPin,
+ PinName ButtonPin) : CBBTrackball(BluePin,
+ RedPin,
+ GreenPin,
+ WhitePin,
+ UpPin,
+ DownPin,
+ LeftPin,
+ RightPin,
+ ButtonPin),
+ m_IterationsSinceLastMotion(INT_MAX)
+ {
+ }
+ void GetState(int& DeltaX, int& DeltaY, int& ButtonPressed);
+
+protected:
+ void UpdateLEDColourBasedOnMotion(int VelocityX,
+ int VelocityY,
+ int ButtonPressed);
+
+ int m_IterationsSinceLastMotion;
+ CAcceleratedRoller<250, 4, 4, 40> m_UpAcceleration;
+ CAcceleratedRoller<250, 4, 4, 40> m_DownAcceleration;
+ CAcceleratedRoller<250, 4, 4, 30> m_LeftAcceleration;
+ CAcceleratedRoller<250, 4, 4, 30> m_RightAcceleration;
+};
+
+#endif // _ACCELERATION_H_
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sun Dec 11 05:38:54 2011 +0000
@@ -0,0 +1,57 @@
+/* Copyright 2011 Adam Green (http://mbed.org/users/AdamGreen/)
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+/* Interfaces to a Sparkfun Blackberry Trackball Breakout Board and uses mbed's
+ USBMouse class to make it look like a mouse to a PC. Uses the trackball
+ motion to move the mouse pointer, pushing down on the trackball will trigger
+ a microswitch which will act as a left button click, and the LEDs under the
+ trackball will be lit different colours depending on what the user is
+ currently doing with the device (red for no motion, green when the trackball
+ is being moved, and blue during button clicks). It does use some other
+ utility classes from acceleration.h to provide acceleration to the trackball
+ motion.
+*/
+#include <mbed.h>
+#include <USBMouse.h>
+#include "acceleration.h"
+
+
+
+int main()
+{
+ static USBMouse Mouse;
+ static CAcceleratedTrackball Trackball(p20, // BLU
+ p25, // RED
+ p26, // GRN
+ p10, // WHT
+ p5, // UP
+ p6, // DWN
+ p7, // LFT
+ p8, // RHT
+ p9); // BTN
+
+ for(;;)
+ {
+ int DeltaX;
+ int DeltaY;
+ int ButtonPressed;
+
+ Trackball.GetState(DeltaX, DeltaY, ButtonPressed);
+
+ Mouse.update(DeltaX,
+ DeltaY,
+ ButtonPressed ? MOUSE_LEFT : 0,
+ 0);
+ }
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Sun Dec 11 05:38:54 2011 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/078e4b97a13e