multiple analog reads

I am trying to read two analog pins but I get the following error message:

var r = binding.read(fd, buffer, offset, length, position);

^

Error: EAGAIN, resource temporarily unavailable

at Object.fs.readSync (fs.js:481:19)

at Object.fs.readFileSync (fs.js:315:28)

at Object.exports.readAIN (/usr/local/lib/node_modules/bonescript/hw_capemgr.js:214:30)

at Object.f.analogRead (/usr/local/lib/node_modules/bonescript/index.js:229:15)

The code below is from the ‘fade’ demo example. I can read either one at a time but when both are in the loop the error occurs after a while. Is the ADC still busy when the second analogRead occurs?

Linux beaglebone 3.8.13-bone47 #1 SMP Fri Apr 11 01:36:09 UTC 2014 armv7l GNU/Linux

BeagleBone Black rev 00C0 running BoneScript 0.2.4

var b = require(‘bonescript’);

// setup starting conditions

var awValue = 0.01;

var awDirection = 1;

var awPin = “P9_14”;

var AnaloginputPin = “P9_38”;

var MyTargetVoltage = 0;

var PWMAnalogVoltage = “P9_36”;

var PWMAnalogVoltVal = 0;

var Analogvalue = 0;

// configure pin

b.pinMode(awPin, b.ANALOG_OUTPUT);

// call function to update brightness every 10ms

setInterval(fade, 100);

// function to update brightness

function fade() {

b.analogWrite(awPin, awValue);

awValue = awValue + (awDirection*0.01);

Analogvalue = b.analogRead(AnaloginputPin);

MyTargetVoltage = Analogvalue * 1.803;

console.log(MyTargetVoltage);

PWMAnalogVoltVal = b.analogRead(PWMAnalogVoltage) * 1.803;

console.log(PWMAnalogVoltVal);

if(awValue > 1.0) { awValue = 1.0; awDirection = -1; }

else if(awValue <= 0.01) { awValue = 0.01; awDirection = 1;}

}

output is

0.20333833333333334

0.44273666666666667

0.18530833333333332

0.44273666666666667

0.19632666666666665

0.441735

0.18130166666666664

0.44273666666666667

0.23338833333333334

0.441735

0.22136833333333333

0.44273666666666667

0.19332166666666664 … until error message