Bhakti Kulkarni / Mbed 2 deprecated USB_Project_Host

USB Host

Dependencies:   C12832_lcd DebounceInterrupts USBHost mbed

Fork of USBHostMouse_HelloWorld by Samuel Mokrani

You are viewing an older revision! See the latest version

Homepage

Table of Contents

  1. USB Mouse

USB Mouse

Goal

To build a USB Mouse (Host and device) using two MBEDs and test the communication between them.

Details

This is a host part of the USB mouse Project. The USB mouse project uses two MBED boards.

There is a bubble on the LCD of the Host MBED. The position of this bubble can be controlled using the potentiometers on the device MBED.

Pin Mappings(Device side)

  • Pot1 is used to control Y position of the bubble
  • Pot2 is used to control X position of the bubble
  • Right button on joystick is used to emulate the right click
  • Left button on joystick is used to emulate the left click
  • Center button of joystick is used to emulate the pressing of the wheel

Pin Mapping (Host side)

  • LED1 : Left Click
  • LED2 : Right Click
  • LED3 : Middle Click

Block Diagram/Connection diagram

/media/uploads/bhakti08/block_diagram.jpg

Design Constraints

The output of the USB mouse(device) is adjusted according to the limits of the LCD on the other MBED board(the host). Due to this this mouse positions may be incorrect for any other sizes of the LCD or the Host computer.

Complete Testing(For both device and host)

Case DescriptionOutput ExpectedActual OutputStatus
ConnectionThe USB device should be properly enumerated when connected to the hostConnection recognized by the hostPASS
If the device is disconnected from the host, there should be some error messageWhen the device is disconnected, the LED4 on Host turns OFF and "Connect the USB mouse" is displayed on the LCDPass
Move Pot1 on the device and check the position of bubble on the Host.The pot should be able to control the bubble for the entire range of the LCD.Using Pot1 the Y position is controlled and the bubble moves from topmost position to bottom most positionPASS
Move Pot2 on the device and check the position of bubble on the Host.The pot should be able to control the bubble for the entire range of the LCD.Using Pot2 the X position is controlled and the bubble moves from leftmost position to the rightmost positionPASS
Press the left switch of the joystick on the deviceThe left click should be detected and the LED on the host should turn ONLED2 on the host turns ON. Thus, a left click on the device is detected by the host.PASS
Press the right switch of the joystick on the deviceThe right click should be detected and the LED on the host should turn ONLED1 on the host turns ON. Thus, a right click on the device is detected by the host.PASS
Press the center switch of the joystick on the deviceThe click of the wheel should be detected and the LED on the host should turn ONLED3 on the host turns ON. Thus, a wheel the wheel being clicked the device is detected by the host.PASS
Disconnect the host from the deviceThe LED4 on the host should turn OFFThe LED4 turns OFF along with the message on the LCD "Connect the USB mouse".PASS

Testing (Host Specific)

Test DescriptionExpected OutputActual OutputStatus
PowerThe host should be able to supply power to the host.The device gets power from the host. No external supply is needed for the devicePASS
Load the USB bus and check if required power is supplied to the deviceThe host should be capable of supplying the power required by the device even under full load conditionNot TestedNA
Check the host outputs before connecting the device to the hostThe host LED4 (Connection LED) should be OFF and the error message should be displayed on the LCD.LED4 on host turns OFF and the error is displayedPASS

Import programUSB_Project_Host

USB Host

Last commit 27 Mar 2014 by Bhakti Kulkarni

main.cpp

/*****************************************************************************/
/*Function: This program is used to emulate a USB Mouse. The mouse position  */
/*          can be changed by the potentiometers. The output values of x and */
/*          y are modified to move the bubble on the LCD on another MBED     */
/*          acting as USB Host. The program for MBED USB Host can be found at*/
/*          http://mbed.org/users/bhakti08/code/USB_Project_Host/            */
/*Author:   Bhakti Kulkarni                                                  */
/*Date:     03/27/2014                                                       */
/*****************************************************************************/
#include <mbed.h>
#include <USBMouse.h>
#include "DebouncedIn.h"
#include "C12832_lcd.h"
#include "DebouncedInterrupt.h"

#define RANGE 0.02
#define INTERRUPT
#define X_MAX 120
#define Y_MAX 28
#define x_move 7
#define y_move 3

Serial pc(USBTX,USBRX);

DebouncedIn right_click(p13);      //Button enulating right click
DebouncedIn left_click(p16);       //Button emulating left click
DebouncedIn wheel(p14);            //Button emulating the wheel button
C12832_LCD lcd;
AnalogIn X_in(p20);               //Analog input to move bubble in x position
AnalogIn Y_in(p19);               //Analog input to move bubble in y position
 
USBMouse  Mouse;

int Xpos = 0;
int Ypos = 0;

/*****************************************************************************/ 
/*This is the main program. This reads the input from the potentiometers,    */
/*converts them into the values that are required for the lcd display        */
/*and then sends them as the mouse outputs.                                  */
/*****************************************************************************/ 
int main()
{
   float AinX_old = 0;
   float AinX_new;
   float AinY_old = 0;
   float AinY_new;
   while (true){
        if(left_click)
        {
            Mouse.click(MOUSE_LEFT);  //if left click is pressed,
                                      // emulate mouse left
        }
        if (right_click)
        {
            Mouse.click(MOUSE_RIGHT);  //if right click is pressed,
                                      // emulate mouse right
        }
        if (wheel)
        {
            Mouse.click(MOUSE_MIDDLE); //if wheel button is pressed,
                                      // emulate wheel button pressed
        }
        AinX_new = X_in.read();
        //check if the values are between the LCD values
        if (AinX_new >= AinX_old + RANGE){         
            if (Xpos < X_MAX)
                Xpos += x_move;
            else
                Xpos = Xpos;
            AinX_old = AinX_new;        
        }
        else if (AinX_new < AinX_old - RANGE){
            if (Xpos > 0)
                Xpos -= x_move;
            else
                Xpos = Xpos;
            AinX_old = AinX_new;        
        }
        else
            Xpos = Xpos;
            
        AinY_new = Y_in.read();
        if (AinY_new >= AinY_old + RANGE){
            if (Ypos < Y_MAX)
                Ypos += y_move;
            else
                Ypos = Ypos;
            AinY_old = AinY_new;        
        }
        else if (AinY_new < AinY_old - RANGE){
            if (Ypos > 0)
                Ypos -= y_move;
            else
                Ypos = Ypos;
            AinY_old = AinY_new;        
        }
        else
            Ypos = Ypos;
        Mouse.move(Xpos,Ypos);      //Send the values as the mouse output
    }
}

/*****************************************************************************/

Device code

Import programUSB_Project_Device

This is a USB mouse(Device). The mouse positions can be changed with the potentiometers on the MBD

Last commit 27 Mar 2014 by Bhakti Kulkarni

main.cpp

/*****************************************************************************/
/*                                   USB MOUSE HOST                          */
/*Function: This program is used to connect the MBED USB mouse. The bubble   */
/*          on the LCD moves according to the input from the USB device.     */
/*          The program for the MBED USB Device can be found at following    */
/*          location:                                                        */
/*          <http://mbed.org/users/bhakti08/code/USB_Project_Device/>        */
/*Author:   Bhakti Kulkarni                                                  */
/*Date:     03/27/2014                                                       */
/*****************************************************************************/

#include "mbed.h"
#include "USBHostMouse.h"
#include "C12832_lcd.h"
#include "DebouncedInterrupt.h"
#include "DebouncedIn.h"

DigitalOut connect(LED4);     //LED to indicate USB Mouse connected
C12832_LCD lcd;
Serial pc(USBTX,USBRX);
BusOut button (LED1,LED2,LED3);   //LEDs for the Button pressed on Device

/*Global Variables to process the X abd Y values*/
int x_lcd=0,y_lcd=0;
int Xpos=0,Ypos=0;
uint8_t buttons; 
int8_t x; 
int8_t y; 
int8_t z;
uint8_t b;

/*****************************************************************************/
/*Function: OnMouseEvent()                                                   */
/*          This function is called whenever there is change in mouse data   */
/*          It copies the values of x,y and buttons from the device into     */
/*          variables that can be accessed by the main logic to move the     */
/*          bubble on the LCD                                                */
/*Inputs:   The x,y and button values from the Mouse.                        */
/*Outputs:  None.                                                            */
/*****************************************************************************/
void onMouseEvent(uint8_t buttons, int8_t x, int8_t y, int8_t z) {
    pc.printf("Mouse values: x= %d, y= %d\r\n",x,y);
    //pc.printf("Buttons are: %d/r/n",buttons);
    Xpos = x;
    Ypos = y;
    b = buttons;// & 0x03;
}
/*****************************************************************************/

/*****************************************************************************/
/*This thread is the mouse_task thread which will check for the USB Device   */
/*connectivity. If the device is not connected it will issue an error message*/
/*Once the device is connected, this thread will attach the mouse event      */
/*thread.                                                                    */
/*****************************************************************************/
void mouse_task(void const *) {
    
    USBHostMouse mouse;
    
    while(1) {
        
        // try to connect a USB mouse
        while(!mouse.connect()){
            lcd.cls();
            lcd.locate(0,0);
            lcd.printf("Connect the USB Mouse\n");
            Thread::wait(500);
        }
    
        // when connected, attach handler called on mouse event
        mouse.attachEvent(onMouseEvent);
        
        // wait until the mouse is disconnected
        while(mouse.connected()){
            lcd.cls();
            connect = 1;
            lcd.fillcircle(Xpos,Ypos, 2, 1); 
            wait(.05);
            lcd.fillcircle(Xpos,Ypos, 2, 1);
            pc.printf("%d\r\n",b); 
            button = b;
            Thread::wait(100);
        }
         connect= 0;
    }
}
/*****************************************************************************/

/*****************************************************************************/
/*This is the main thread. This will do nothing but initiate the mouse task  */
/*thread and then wait forever in the loop                                   */
/*****************************************************************************/ 
int main() {
    Thread mouseTask(mouse_task, NULL, osPriorityNormal, 256 * 4);
    while(1) {
        Thread::wait(osWaitForever);
    }
}
/*****************************************************************************/
All wikipages