> > *Error: EAGAIN, resource temporarily unavailable*
I can not speak to bonescript, or what you're using javascript wise. But I can say that this error can happen when the ADC channel in question is not done updating the "buffer". So in the C programming language, what you end up having to do is close the file descriptor, reopen the file descriptor, then try again. When the length of the read file descriptor returns -1. How this applies to your javascript code . . . I could not say, but there you have it. On Sun, Oct 4, 2015 at 5:34 PM, alan dussel <[email protected]> wrote: > i am not sure but i think buried somewhere in the BBB service reference > manual ( i think that is the right name ) it mentions something that made > me think, there is only one A/D converter and the other inputs are > multiplexed. Another thing to check might be the pin you are trying to use > maybe already used by some other device or service. I am using an LCD 7 > which consumes four of the A/D inputs. > > hope that helps ! > > > > On Thursday, September 24, 2015 4:17 PM, 'Don Terry' via BeagleBoard < > [email protected]> wrote: > > > I have searched BeagleBoard forums for this answer but only found single > A/D responses. Since I already have a single A/D channel working this was > no help. > > 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 > > Thanks > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
