Error when reading multiple Analog Inputs recursively

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1

I’ve been using Blacklib (http://blacklib.yigityuce.com/index.html) to read 6 of the Analog Inputs of my Beaglebone but I keep get getting this error:

terminate called after throwing an instance of ‘std::ios_base::failure’ what(): basic_filebuf::underflow error reading the file

It doesn’t happen always at the same time, but it will eventually happen at some point. This is my code:

BlackADC * a;
BlackADC * b;
BlackADC * c;
BlackADC * d;
BlackADC * e;
BlackADC * f;

a=new BlackADC(AIN0); 
b=new BlackADC(AIN1); 
c=new BlackADC(AIN2);
d=new BlackADC(AIN3); 
e=new BlackADC(AIN4); 
f=new BlackADC(AIN5); 

temp_a=a->getConvertedValue(dap2);
while(temp_a==-1.0)
    {
        temp_a=a->getConvertedValue(dap2);
    }
s.a=temp_a;

temp_b=b->getConvertedValue(dap2);
while(temp_b==-1.0)
    {
        temp_b=b->getConvertedValue(dap2);
    }
s.b=temp_b;
temp_c=c->getConvertedValue(dap2);
while(temp_c==-1.0)
    {
        temp_c=c->getConvertedValue(dap2);
    }
s.c=temp_c;

temp_d=d->getConvertedValue(dap2);
while(temp_d==-1.0)
    {
        temp_d=d->getConvertedValue(dap2);
    }
s.d=temp_d;

temp_e=e->getConvertedValue(dap2);
while(temp_e==-1.0)
    {
        temp_e=e->getConvertedValue(dap2);
    }
s.e=temp_e;

temp_f=f->getConvertedValue(dap2);
while(temp_f==-1.0)
    {
        temp_f=f->getConvertedValue(dap2);
    }
s.f=temp_f;

s is a struct that I use to collect all those values together. The read is in a loop that has to run until the user kills it (for periods of about 1 hour) and the values are read as fast as it is possible.

Any suggestions…???

2

That is because this the the incorrect way to read ADC values. The ADC driver is based on the IIO framework, so instead of reading ADC values via sysfs, you should read the values from /dev/iio:device0. Search for "generic_buffer.c IIO” to see how to do this correctly.

Regards,
John