javascript / bonescript structure

[ddch...@gmail.com]

i am coming from a background of PIC mcu and arduino.  i have a BBB and a Raspberry PI.  i prefer the BBB because of the amount of gpios.  i have some coding experience using C and the arduino programming language.  so i am used to using that structure.

headers and include files

declare Variables

do you set up of ports, pin modes, and/or peripherals.

main loop

user defined functions

My question is what is the structure of a program when using javascript/bonescript to program the BBB.  I have read and watched videos of derek molloy that i can just write C or C++ code on the BBB, which requires me to understand the file system and the exporting of the gpios and all that.  i am not ready to do that just yet.  i have also seen that python is a good option for both the BBB and the raspberry pi, but i want to try the bonescript/javascript first and try writing some code to control a robot.  right now i am working out some code to check the number of rotations using disk wheel encoders, so that i can calibrate my motors.  i have included the code i am trying to work out.  so far this works to count the rotations and output the information to the console, but from here i get stuck.

if i was doing this on a mcu:

1) i would create variable and configure my interrupt on change pins

2) write the isr's to check and do the math, when an interrupt occured

3) configure a timer interrupt to check every 1 second then reset the timer

4) write a "main loop" program to control the motors and make adjustments to the pwm until all rotation variables are equal in value

or something like that.

with this code i tried to do what i listed above, and like i said i have some success, but after this how would i make a loop for the motors do i need to make a loop for the motors?  do i just write what i want the motors to do?  is there a structure to follow?

//calling bonescript library

var b = require('bonescript');

//variables used for interrupts and counting

var motor1 = 'P9_15';

var motor2 = 'P9_17';

var motor3 = 'P8_16';

var motor4 = 'P8_18';

var counter1 = 0;

var counter2 = 0;

var counter3 = 0;

var counter4 = 0;

var diskslots = 20;

//Setting all motor pins as inputs

b.pinMode(motor1, b.INPUT);

b.pinMode(motor2, b.INPUT);

b.pinMode(motor3, b.INPUT);

b.pinMode(motor4, b.INPUT);

//Interrupt Service Routines

function ISR_Count1()

{

counter1++;

}

function ISR_Count2()

{

        counter2++;

}

function ISR_Count3()

{

        counter3++;

}

function ISR_Count4()

{

        counter4++;

}

//make motor pins external interrupts

b.attachInterrupt(motor1, true, b.CHANGE, ISR_Count1);

b.attachInterrupt(motor2, true, b.CHANGE, ISR_Count2);

b.attachInterrupt(motor3, true, b.CHANGE, ISR_Count3);

b.attachInterrupt(motor4, true, b.CHANGE, ISR_Count4);

//Function to count the rotaions and output data to console log

function motorOut()

{

b.detachInterrupt(motor1);

        var rotation1 = counter1/20;

        console.log("Motor 1: ", rotation1);

counter1 = 0;

b.detachInterrupt(motor2);

        var rotation2 = counter2/20;

        console.log("Motor 2: ", rotation2);

counter2 = 0;

        b.detachInterrupt(motor3);

        var rotation3 = counter3/20;

        console.log("Motor 3: ", rotation3);

counter3 = 0;

        b.detachInterrupt(motor4);

        var rotation4 = counter4/20;

        console.log("Motor 4: ", rotation4);

counter4 = 0;

}

setInterval(motorOut,1000); 

   

sorry for the unorganizedness of this post.  its midnight where im at and sleep may 5 hrs a night for the last eight months.  

[TJF]

You don't need interrupts for counting pulses. Instead use the hardware counters inbuild in the AM335x CPU. Those are

• 3xPWMSS.eQEP
• 3xPWMSS.eCAP
• 4xTIMERSS

Find details and example code (C, Python, BASIC) in the libpruio documentation.

Regards

[ddch...@gmail.com]

this is what i was looking for.  how do i access the timers that the BBB has?  that link will lead me to all that?