Hello all,

I am trying to use two raspberry-pi to sample and then process some data. The first process samples while the second processes and vice versa. To do this I use gpio and also mpich-3.0.4 with the process manager smpd. I have successfully run cpi on both machines (from the master machine). I have also managed to run a similar program but without the MPI, this involved compiling with gcc and when running putting sudo in front of the binary file.

When I combine these two processes I get various error messages. 
For input:
mpiexec -phrase cat -machinefile machinefile -n 2 ~/main 
the error is:
Can't open /dev/mem
Did you forget to use 'sudo .. ?'

For input:
sudo mpiexec -phrase cat -machinefile machinefile -n 2 ~/main 
the error is:
sudo: mpiexec: Command not found

I therefore put mpiexec into /usr/bin

now for input:
sudo mpiexec -phrase cat -machinefile machinefile -n 2 ~/main 
the error is:
Can't open /dev/mem
Did you forget to use 'sudo .. ?'

Does anyone know how I can work around this?
Thanks,
Eibhlin