Marco Virgolin / Mbed 2 deprecated ProgEmbedded_Joystick

Program that reads data from the FRDM-KL25Z capacitive slider and accellerometer and sends it to the serial port in JSON format.

Dependencies:   MMA8451Q TSI mbed

Fork of FRDM_TSI by Subhrajit Mitra

This code is part of a project for the course in Computer Engineering "Progettazione di Applicazioni per Dispositivi Embedded (Designing of Applications for Embedded Devices)" , held by professor Omero Tuzzi, at the University of Trieste.

The code reads data from the board sensors (capacitive touch slider and accelerometer) and makes the RGB led assume a color according to the readings. It also sends a JSON-format message about the readings to the USB Serial Port.

main.cpp@7:ebf728afc308, 2014-09-21 (annotated)

Committer:
remarkus89
Date:
Sun Sep 21 16:48:20 2014 +0000
Revision:
7:ebf728afc308
Parent:
6:38459146ad89 
Added comments to explain the code.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
remarkus89 7:ebf728afc308 1 // Inclusion of necessary libraries
emilmont 0:0f00f07ebde0 2 #include "mbed.h"
chris 1:51b1b688179a 3 #include "TSISensor.h"
subhrajitmitra 5:7f7b888f616b 4 #include "MMA8451Q.h"
remarkus89 6:38459146ad89 5 #include "stdio.h"
subhrajitmitra 5:7f7b888f616b 6
remarkus89 7:ebf728afc308 7 // Declaration of constants
subhrajitmitra 5:7f7b888f616b 8 #define MMA8451_I2C_ADDRESS (0x1d<<1)
remarkus89 6:38459146ad89 9 #define ACC_THRESH 0.1
remarkus89 6:38459146ad89 10 #define WAIT_TIME 0.01
emilmont 0:0f00f07ebde0 11
emilmont 0:0f00f07ebde0 12 int main(void) {
remarkus89 7:ebf728afc308 13 // Declare accelerometer
subhrajitmitra 5:7f7b888f616b 14 MMA8451Q acc(PTE25, PTE24, MMA8451_I2C_ADDRESS);
subhrajitmitra 5:7f7b888f616b 15
remarkus89 7:ebf728afc308 16 // Declare components of the RGB led
remarkus89 6:38459146ad89 17 PwmOut led_blue(LED_BLUE);
remarkus89 6:38459146ad89 18 PwmOut led_green(LED_GREEN);
remarkus89 6:38459146ad89 19 PwmOut led_red(LED_RED);
subhrajitmitra 5:7f7b888f616b 20
remarkus89 7:ebf728afc308 21 // Declare capacitive touch slider
subhrajitmitra 5:7f7b888f616b 22 float tp=0;
subhrajitmitra 5:7f7b888f616b 23 TSISensor tsi;
remarkus89 7:ebf728afc308 24
remarkus89 7:ebf728afc308 25 // Declare USB Serial Port
remarkus89 6:38459146ad89 26 Serial pc(USBTX, USBRX);
remarkus89 7:ebf728afc308 27
remarkus89 7:ebf728afc308 28 // Turn off all the components of the RGB led
remarkus89 6:38459146ad89 29 led_blue = 1;
remarkus89 6:38459146ad89 30 led_green = 1;
remarkus89 6:38459146ad89 31 led_red = 1;
subhrajitmitra 5:7f7b888f616b 32
subhrajitmitra 5:7f7b888f616b 33 while (1)
subhrajitmitra 5:7f7b888f616b 34 {
remarkus89 7:ebf728afc308 35 // Read the slider and assign the readed value to the tp variable.
remarkus89 7:ebf728afc308 36 // tp assumes a value between 0 (user is not touching the slider)
remarkus89 7:ebf728afc308 37 // and 1 (user is touching the upper part of the slider).
remarkus89 6:38459146ad89 38 tp = tsi.readPercentage();
remarkus89 7:ebf728afc308 39
remarkus89 7:ebf728afc308 40 // If the user is NOT touching the slider, then make RGB led assume
remarkus89 7:ebf728afc308 41 // a color accourding to the declivity measured by the accelerometer.
remarkus89 7:ebf728afc308 42 // Green intensity is used to represent the vertical axe (y),
remarkus89 7:ebf728afc308 43 // Blue intensity is used to represent the horizontal one (x).
remarkus89 6:38459146ad89 44 if (tp == 0){
remarkus89 6:38459146ad89 45 led_red = 1;
remarkus89 6:38459146ad89 46 if (abs(acc.getAccX()) >= ACC_THRESH)
remarkus89 6:38459146ad89 47 led_blue = 1-abs(acc.getAccX());
remarkus89 6:38459146ad89 48 else
remarkus89 6:38459146ad89 49 led_blue = 1;
remarkus89 6:38459146ad89 50 if (abs(acc.getAccY()) >= ACC_THRESH)
remarkus89 6:38459146ad89 51 led_green = 1-abs(acc.getAccY());
remarkus89 6:38459146ad89 52 else
remarkus89 6:38459146ad89 53 led_green = 1;
remarkus89 7:ebf728afc308 54 // If the user is touching the upper part of the slider, make the RGB led
remarkus89 7:ebf728afc308 55 // assume the Red color
remarkus89 6:38459146ad89 56 } else if (tp >= 0.5) {
remarkus89 6:38459146ad89 57 led_blue = 1;
remarkus89 6:38459146ad89 58 led_green = 1;
remarkus89 6:38459146ad89 59 led_red = 0;
remarkus89 7:ebf728afc308 60 // If the user is touching the lower part of the slider, make the RGB led
remarkus89 7:ebf728afc308 61 // assume the White color
remarkus89 6:38459146ad89 62 } else {
remarkus89 6:38459146ad89 63 led_blue = 0;
remarkus89 6:38459146ad89 64 led_green = 0;
remarkus89 6:38459146ad89 65 led_red = 0;
remarkus89 6:38459146ad89 66 }
remarkus89 7:ebf728afc308 67 // Send a JSON-format message of the measurements to the Serial Port
remarkus89 6:38459146ad89 68 pc.printf("{ \"slider\" : %f, \"acc_x\" : %f, \"acc_y\" : %f, \"acc_z\" : %f }\n", tp, acc.getAccX(), acc.getAccY(), acc.getAccZ());
remarkus89 7:ebf728afc308 69 // Wait a fixed amount of time before repeating the whole while-cycle
remarkus89 6:38459146ad89 70 wait(WAIT_TIME);
emilmont 0:0f00f07ebde0 71 }
chris 1:51b1b688179a 72 }