T.H. Lu
Use Accelerometer and Joystick to mimic a mouse. This is for a class project. It is done for educational purpose. It is not practical to real world use.
Dependencies: C12832_lcd MMA7660 USBDevice mbed
Revision 0:22bdcdc386df, committed 2014-03-15
- Comitter:
- thlu
- Date:
- Sat Mar 15 09:32:43 2014 +0000
- Child:
- 1:03d0f8a4a2d7
- Commit message:
- Got calibration working using x,y, and z-axes
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/C12832_lcd.lib Sat Mar 15 09:32:43 2014 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/dreschpe/code/C12832_lcd/#8f86576007d6
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MMA7660.lib Sat Mar 15 09:32:43 2014 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/Sissors/code/MMA7660/#a8e20db7901e
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/USBDevice.lib Sat Mar 15 09:32:43 2014 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/USBDevice/#335f2506f422
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/accelestick.cpp Sat Mar 15 09:32:43 2014 +0000
@@ -0,0 +1,291 @@
+#include "accelestick.h"
+
+inline void reset_tm_joystick_dc()
+{
+ tm_joystick_running = 0;
+ tm_joystick_dc.stop();
+ tm_joystick_dc.reset();
+}
+
+// This function checks for joystick button presses which emulate a mouse's
+// left button, right button, middle button, double click, and scroll
+// features. Double click requires a timer
+void get_joystick_input()
+{
+ static uint8_t prev_js = 0;
+ static bool debug_sel_en = 0;
+ static int mouse_scroll = 0;
+
+ mouse_info.button = 0;
+ mouse_info.scroll = 0;
+ mouse_info.dc = 0;
+
+ if (debug_on && debug_sel_en && (joyb != JS_NONE)) {
+ debug_sel_en = 0;
+ debug_sel = joyb;
+ }
+
+ if (debug_on && (debug_sel == JS_NONE) && (joyb == JS_NONE)) {
+ debug_sel_en = 1;
+ }
+
+ switch(joyb) { // 1 = down, 2 = left, 4 = center, 8 = up, 16 = right
+ case JS_LEFT:
+ // 1 click = left button, 2 clicks = double click
+ if ((prev_js != JS_LEFT) && (tm_joystick_running == JS_LEFT)) { // double click
+ mouse_info.dc = 1;
+ reset_tm_joystick_dc();
+ } else if (!tm_joystick_running) {
+ tm_joystick_running = JS_LEFT;
+ tm_joystick_dc.start();
+ }
+ mouse_info.button = MOUSE_LEFT;
+ break;
+ case JS_CENTER: // center
+ if ((prev_js != JS_CENTER) && (tm_joystick_running == JS_CENTER)) { // double click
+ calib_on = 1;
+ reset_tm_joystick_dc();
+ } else if (!tm_joystick_running) {
+ tm_joystick_running = JS_CENTER;
+ tm_joystick_dc.start();
+
+ }
+ mouse_info.button = MOUSE_MIDDLE;
+ break;
+ case JS_RIGHT:
+ if ((prev_js != JS_RIGHT) && (tm_joystick_running == JS_RIGHT)) {
+ debug_on = !debug_on;
+ reset_tm_joystick_dc();
+ lcd.cls();
+ lcd.locate(0,0);
+ if (debug_on) {
+ lcd.printf("Debug print is ON\n");
+ debug_sel = JS_NONE;
+ debug_sel_en = 0;
+ }
+ } else if (!tm_joystick_running) {
+ tm_joystick_running = JS_RIGHT;
+ tm_joystick_dc.start();
+ }
+ mouse_info.button = MOUSE_RIGHT;
+ break;
+ case JS_DOWN: // down
+ if (prev_js == JS_DOWN) {
+ mouse_scroll++;
+ } else {
+ mouse_scroll = 1; // >0 means down
+ }
+ debug.printf("down scroll = %0d\r\n", mouse_info.scroll);
+ reset_tm_joystick_dc();
+ mouse_info.scroll = mouse_scroll;
+
+ break;
+ case JS_UP: // up
+ if (prev_js == JS_UP) {
+ mouse_scroll--;
+ } else {
+ mouse_scroll = -1;
+ }
+ debug.printf("up scroll = %0d\r\n", mouse_info.scroll);
+ reset_tm_joystick_dc();
+ mouse_info.scroll = mouse_scroll;
+ break;
+ }
+
+
+ if (tm_joystick_dc.read_ms() > 1000) { // timeout for double-click detection
+ reset_tm_joystick_dc();
+ }
+
+ prev_js = joyb;
+}
+
+
+void sample_mma() // Accelerometer value ranges from -1.5 to 1.5
+{
+ mma_g.x = mma.x();
+ mma_g.y = mma.y();
+ mma_g.z = mma.z();
+ G_int_t current;
+
+ if (mma_g.x > peaks.max_x) {
+ peaks.max_x = mma_g.x;
+ } else if (mma_g.x < peaks.min_x) {
+ peaks.min_x = mma_g.x;
+ }
+ if (mma_g.y > peaks.max_y) {
+ peaks.max_y = mma_g.y;
+ } else if (mma_g.y < peaks.min_y) {
+ peaks.min_y = mma_g.y;
+ }
+ if (mma_g.z > peaks.max_z) {
+ peaks.max_z = mma_g.z;
+ } else if (mma_g.z < peaks.min_z) {
+ peaks.min_z = mma_g.z;
+ }
+
+ current = conv_g2int(mma_g);
+ if (calib_on) {
+ calib_mma(current);
+ }
+ mouse_info.x = current.x - offset.x;
+ mouse_info.y = current.y - offset.y;
+ mouse_info.z = current.z - offset.z;
+ detect_mma_rest();
+}
+
+void drive_mouse()
+{
+ // x-direction is reversed on PC screen
+ mouse.move(-mouse_info.x, mouse_info.y);
+ mouse.press(mouse_info.button);
+ mouse.scroll(mouse_info.scroll);
+ if (mouse_info.dc) {
+ mouse.doubleClick();
+ }
+}
+
+// Used for debugging
+void print_debug_msg()
+{
+ if (debug_on) {
+ switch (debug_sel) {
+ case JS_LEFT:
+ debug.printf("Mx = %1.2f, mx = %1.2f ", peaks.max_x, peaks.min_x);
+ debug.printf("My = %1.2f, my = %1.2f ", peaks.max_y, peaks.min_y);
+ debug.printf("Mz = %1.2f, mz = %1.2f\r\n", peaks.max_z, peaks.min_z);
+ break;
+ case JS_CENTER:
+ debug.printf("x=%1.2f y=%1.2f z=%1.2f\r\n", mma_g.x, mma_g.y, mma_g.z);
+ debug.printf("x=%0d, y=%0d, z=%0d, button=%0d, scroll=%0d, dc=%0d\r\n\n",
+ mouse_info.x, mouse_info.y, mouse_info.z, mouse_info.button,
+ mouse_info.scroll, mouse_info.dc);
+ break;
+ case JS_RIGHT:
+ debug.printf("offset.x=%0d, y=%0d, z=%0d\r\n", offset.x, offset.y, offset.z);
+ break;
+ }
+ }
+}
+
+// calibrate the accelerometer for leveling
+void calib_mma(const G_int_t current)
+{
+ static uint8_t ctr = 0;
+ static G_int_t prev[CALIB_SMPLS]; // average array
+
+ int temp;
+
+ if (ctr == 0) {
+ lcd.cls();
+ lcd.locate(0,0);
+ lcd.printf("Calibrating mma");
+ wait(3);
+ } else {
+ lcd.printf(".");
+ }
+ prev[ctr++] = current;
+
+ if (ctr == CALIB_SMPLS) {
+ temp = 0;
+ for (uint8_t i=0; i<CALIB_SMPLS; i++) {
+ debug.printf("CALIB[%0d]: x=%0d, y=%0d, z=%0d\r\n", i, prev[i].x, prev[i].y, prev[i].z);
+ temp += prev[i].x;
+ }
+ offset.x = temp/CALIB_SMPLS; // average
+
+ temp = 0;
+ for (uint8_t i=0; i<CALIB_SMPLS; i++) {
+ temp += prev[i].y;
+ }
+ offset.y = temp/CALIB_SMPLS;
+
+ temp = 0;
+ for (uint8_t i=0; i<CALIB_SMPLS; i++) {
+ temp += prev[i].z;
+ }
+ offset.z = temp/CALIB_SMPLS;
+
+ ctr = 0;
+ calib_on = 0; // calibration done
+ lcd.cls();
+ lcd.locate(0,0);
+ lcd.printf("Calibration Completed!\n");
+ wait(1);
+ }
+}
+
+void detect_mma_rest ()
+{
+ if ((abs(mouse_info.z) <= 0.06*SCALE_Z) &&
+ (abs(mouse_info.x) <= 0.10*SCALE_X) &&
+ (abs(mouse_info.y) <= 0.10*SCALE_Y)) {
+ mouse_info.x = 0;
+ mouse_info.y = 0;
+ }
+}
+
+// convert mma signed g float value into signed int value
+G_int_t conv_g2int (G_float_t mma_g)
+{
+ G_int_t temp;
+
+ temp.x = (mma_g.x * SCALE_X);
+ temp.y = (mma_g.y * SCALE_Y);
+ temp.z = (mma_g.z * SCALE_Z);
+ return temp;
+}
+
+//
+void flash_led_alive()
+{
+ static bool led_state = 0;
+ led_alive = led_state;
+ led_state = !led_state;
+
+}
+
+int8_t init_accelestick()
+{
+ lcd.cls();
+ reset_tm_joystick_dc();
+
+ offset.x = 0;
+ offset.y = 0;
+ offset.z = 1.0*SCALE_Z;
+
+ peaks.max_x=ACCEL_MIN, peaks.max_y=ACCEL_MIN, peaks.max_z=ACCEL_MIN;
+ peaks.min_x=ACCEL_MAX, peaks.min_y=ACCEL_MAX, peaks.min_z=ACCEL_MAX;
+
+ if (!mma.testConnection()) {
+ lcd.printf("Error in MMA init\n");
+ return -1;
+ }
+ tk_led_alive.attach(&flash_led_alive, 1.0);
+ tk_print_debug.attach(&print_debug_msg, 1.0);
+ return 0;
+
+}
+
+int8_t run_accelestick()
+{
+ int8_t status;
+
+ status = init_accelestick();
+
+ if (status != 0) {
+ return -1;
+ }
+
+ while(1) {
+ get_joystick_input();
+ sample_mma();
+ drive_mouse();
+ }
+
+}
+
+int main()
+{
+ run_accelestick();
+}
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/accelestick.h Sat Mar 15 09:32:43 2014 +0000
@@ -0,0 +1,100 @@
+#include <stdlib.h>
+#include "mbed.h"
+
+#ifndef ACCELESTICK_H
+#define ACCELESTICK_H
+
+#include "MMA7660.h" // Accelerometer API
+#include "C12832_lcd.h" // LCD API
+#include "USBMouseKeyboard.h"
+
+#define SCALE_X 50 // g value has noise about 0.05
+#define SCALE_Y SCALE_X
+#define SCALE_Z SCALE_X
+#define ACCEL_MIN -1.5
+#define ACCEL_MAX 1.5
+
+#define CALIB_SMPLS 16 // number of samples used for calibrating accelerometer
+
+// Joystick button values based on joyb declaration
+#define JS_NONE 0
+#define JS_DOWN 1
+#define JS_LEFT 2
+#define JS_CENTER 4
+#define JS_UP 8
+#define JS_RIGHT 16
+
+//--- Global Variables declaration ---//
+
+C12832_LCD lcd; // for debugging
+MMA7660 mma(p28, p27); // I2C Accelerometer
+USBMouseKeyboard mouse;
+DigitalOut led_alive(LED4);
+DigitalOut leds[] = {LED1, LED2, LED3};
+
+DigitalIn jd = p12;
+DigitalIn jl = p13;
+DigitalIn jc = p14;
+DigitalIn ju = p15;
+DigitalIn jr = p16;
+BusIn joyb(p12, p13, p14, p15, p16);
+
+typedef struct s_max_min {
+ float max_x, max_y, max_z;
+ float min_x, min_y, min_z;
+} Max_min_t;
+
+typedef struct s_int_g {
+ int16_t x, y, z;
+} G_int_t;
+
+typedef struct s_float_pos {
+ float x, y, z;
+} G_float_t;
+
+typedef struct
+{
+ int16_t x, y, z; // x, y, z position
+ uint8_t button; // left button, 1 = left, 2 = center, 4 = middle
+ bool dc; // double click
+ int8_t scroll; // <0 to go up, >0 to go down
+} Mouse_state_t;
+
+Max_min_t peaks;
+Mouse_state_t mouse_info;
+G_int_t offset; // calibration offset value
+
+bool calib_on = 0;
+bool debug_on = 0;
+uint8_t tm_joystick_running = 0, debug_sel;
+
+G_float_t mma_g; // g values from accelerometer
+
+Ticker tk_led_alive; // Ticker for flashing LED as program alive beacon
+Ticker tk_print_debug;// Ticker for printing debug information
+Timer tm_joystick_dc; // Timer for joystick double-click detection
+RawSerial debug(USBTX, USBRX);
+
+// End of Global Variable Declaration
+
+
+//--- Functions Declaration ---//
+
+ // calibrate accelerometer
+ void calib_mma(G_int_t current);
+
+ // convert floating MMA g value into integer
+ int16_t scale_g(int8_t g);
+ G_int_t conv_g2int(G_float_t mma_g);
+
+ // detect MMA at rest
+ void detect_mma_rest();
+
+ // Sample joystick for button press
+ void get_joystick_input();
+
+ inline void reset_tm_joystick_dc();
+ int8_t init_accelestick();
+ int8_t run_accelestick();
+
+#endif
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sat Mar 15 09:32:43 2014 +0000
@@ -0,0 +1,9 @@
+/*
+#include "accelestick.h"
+
+int main()
+{
+ run_accelestick();
+
+}
+*/
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Sat Mar 15 09:32:43 2014 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/8e73be2a2ac1 \ No newline at end of file