Jesse Kaiser / Mbed 2 deprecated EMG_HIDScope_Gr6

Highpass en Notch filter voor EMG verwerking

Dependencies:   HIDScope mbed-dsp mbed

Fork of EMG_HIDScope by First Last

main.cpp@16:24e992616cf6, 2014-09-24 (annotated)

Committer:
vsluiter
Date:
Wed Sep 24 08:31:30 2014 +0000
Revision:
16:24e992616cf6
Parent:
15:d3a849ab3697
Parent:
14:94a4a5863689
Child:
17:1388f1a2d7b2
Added filter code (not tested)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
vsluiter 0:32bb76391d89 1 #include "mbed.h"
vsluiter 6:80c13d99aa55 2 #include "MODSERIAL.h"
vsluiter 11:ce72ec658a95 3 #include "HIDScope.h"
vsluiter 0:32bb76391d89 4
vsluiter 4:8b298dfada81 5 //Define objects
vsluiter 7:3396c3e33928 6 AnalogIn emg0(PTB1); //Analog input
ArvidKeemink 1:db54d9412d18 7 PwmOut red(LED_RED); //PWM output
vsluiter 8:8a17f65622b4 8 Ticker log_timer;
vsluiter 8:8a17f65622b4 9 MODSERIAL pc(USBTX,USBRX);
vsluiter 11:ce72ec658a95 10 HIDScope scope(2);
vsluiter 2:e314bb3b2d99 11
vsluiter 15:d3a849ab3697 12 typedef struct second_order_constants
vsluiter 15:d3a849ab3697 13 {
vsluiter 15:d3a849ab3697 14 float b[3];
vsluiter 15:d3a849ab3697 15 float a[3];
vsluiter 15:d3a849ab3697 16 } second_order_constants_t;
vsluiter 15:d3a849ab3697 17
vsluiter 15:d3a849ab3697 18 typedef struct second_order_values
vsluiter 15:d3a849ab3697 19 {
vsluiter 15:d3a849ab3697 20 float x_1,x_2;
vsluiter 15:d3a849ab3697 21 float y_1,y_2;
vsluiter 15:d3a849ab3697 22 } second_order_values_t;
vsluiter 15:d3a849ab3697 23
vsluiter 15:d3a849ab3697 24 //constants
vsluiter 15:d3a849ab3697 25 second_order_constants_t highpass= {{0.97803048, -1.95606096, 0.97803048},{1, -1.95557824, 0.95654368}};
vsluiter 15:d3a849ab3697 26 //type for values
vsluiter 15:d3a849ab3697 27 second_order_values_t highpass_values;
vsluiter 15:d3a849ab3697 28
vsluiter 15:d3a849ab3697 29 float second_order(float x, second_order_constants_t constants, second_order_values_t &values);
vsluiter 15:d3a849ab3697 30
vsluiter 15:d3a849ab3697 31
vsluiter 4:8b298dfada81 32 /** Looper function
vsluiter 4:8b298dfada81 33 * functions used for Ticker and Timeout should be of type void <name>(void)
vsluiter 4:8b298dfada81 34 * i.e. no input arguments, no output arguments.
vsluiter 4:8b298dfada81 35 * if you want to change a variable that you use in other places (for example in main)
vsluiter 4:8b298dfada81 36 * you will have to make that variable global in order to be able to reach it both from
vsluiter 4:8b298dfada81 37 * the function called at interrupt time, and in the main function.
vsluiter 4:8b298dfada81 38 * To make a variable global, define it under the includes.
vsluiter 4:8b298dfada81 39 * variables that are changed in the interrupt routine (written to) should be made
vsluiter 4:8b298dfada81 40 * 'volatile' to let the compiler know that those values may change outside the current context.
vsluiter 8:8a17f65622b4 41 * i.e.: "volatile uint16_t emg_value;" instead of "uint16_t emg_value"
vsluiter 4:8b298dfada81 42 * in the example below, the variable is not re-used in the main function, and is thus declared
vsluiter 4:8b298dfada81 43 * local in the looper function only.
vsluiter 4:8b298dfada81 44 **/
vsluiter 2:e314bb3b2d99 45 void looper()
vsluiter 2:e314bb3b2d99 46 {
vsluiter 4:8b298dfada81 47 /*variable to store value in*/
vsluiter 8:8a17f65622b4 48 uint16_t emg_value;
vsluiter 15:d3a849ab3697 49 float filtered_emg;
vsluiter 4:8b298dfada81 50 /*put raw emg value both in red and in emg_value*/
vsluiter 10:09b8424a7b39 51 red.write(emg0.read()); // read float value (0..1 = 0..3.3V)
vsluiter 12:768048d7f742 52 emg_value = emg0.read_u16(); // read direct ADC result, converted to 16 bit integer (0..2^16 = 0..65536 = 0..3.3V)
vsluiter 15:d3a849ab3697 53 filtered_emg = second_order((float)emg_value,highpass, highpass_values);
vsluiter 8:8a17f65622b4 54 /*send value to PC. Line below is used to prevent buffer overrun */
vsluiter 16:24e992616cf6 55
vsluiter 11:ce72ec658a95 56 scope.set(0,emg_value);
vsluiter 16:24e992616cf6 57 scope.set(1,filtered_emg);
vsluiter 11:ce72ec658a95 58 scope.send();
vsluiter 16:24e992616cf6 59
vsluiter 5:4dacb7b72109 60 /**When not using the LED, the above could also have been done this way:
vsluiter 8:8a17f65622b4 61 * pc.printf("%u\n", emg0.read_u16());
vsluiter 5:4dacb7b72109 62 */
vsluiter 2:e314bb3b2d99 63 }
vsluiter 0:32bb76391d89 64
vsluiter 0:32bb76391d89 65 int main()
vsluiter 0:32bb76391d89 66 {
vsluiter 4:8b298dfada81 67 /*setup baudrate. Choose the same in your program on PC side*/
vsluiter 14:94a4a5863689 68 //pc.baud(115200);
vsluiter 4:8b298dfada81 69 /*set the period for the PWM to the red LED*/
vsluiter 2:e314bb3b2d99 70 red.period_ms(2);
vsluiter 4:8b298dfada81 71 /**Here you attach the 'void looper(void)' function to the Ticker object
vsluiter 9:d33e7b175ad7 72 * The looper() function will be called every 0.01 seconds.
vsluiter 4:8b298dfada81 73 * Please mind that the parentheses after looper are omitted when using attach.
vsluiter 4:8b298dfada81 74 */
vsluiter 13:18d4cef1fdb4 75 log_timer.attach(looper, 0.005);
ArvidKeemink 1:db54d9412d18 76 while(1) //Loop
vsluiter 0:32bb76391d89 77 {
vsluiter 4:8b298dfada81 78 /*Empty!*/
vsluiter 4:8b298dfada81 79 /*Everything is handled by the interrupt routine now!*/
vsluiter 0:32bb76391d89 80 }
vsluiter 15:d3a849ab3697 81 }
vsluiter 15:d3a849ab3697 82
vsluiter 15:d3a849ab3697 83 float second_order(float x, second_order_constants_t constants, second_order_values_t &values)
vsluiter 15:d3a849ab3697 84 {
vsluiter 15:d3a849ab3697 85 float y = 0;
vsluiter 15:d3a849ab3697 86 float b_terms, a_terms;
vsluiter 15:d3a849ab3697 87 b_terms = (constants.b[0]*x) + (constants.b[1]*values.x_1) + (constants.b[2]*values.x_2);
vsluiter 15:d3a849ab3697 88 a_terms = (constants.a[1]*values.y_1) + (constants.a[2]*values.y_2);
vsluiter 15:d3a849ab3697 89 y=(1./constants.a[0])* (b_terms-a_terms);
vsluiter 15:d3a849ab3697 90 values.x_2 = values.x_1;
vsluiter 15:d3a849ab3697 91 values.x_1 = x;
vsluiter 15:d3a849ab3697 92 values.y_2 = values.y_1;
vsluiter 15:d3a849ab3697 93 values.y_1 = y;
vsluiter 15:d3a849ab3697 94 return y;
vsluiter 0:32bb76391d89 95 }