DeviceWrite Error using remote development kit on RPi with Raspbian Jessie

Questions
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1

I know there are older posts on the RDK (eg Remote Kernel on Raspberry Pi ) but I have decided to start a new one because they are old.

I have had full functionality with RDK and running a remote kernel on an RPi in the past, however have problems with it on an RPi 2 running Raspbian Jessie. I’m using Mathematica v10.3.0.0 on OSX.

I get an error when evaluating DeviceWrite on the RPi remote kernel. Other expressions evaluate without any problems eg $MachineID[]; 1+1 etc.

Has anyone seen this error before? Note: the output “18->1” does not actually turn GPIO 18 on.

DeviceWriteerror.png
DeviceWriteerror.png664×266 23.8 KB

DeviceWrite[“GPIO”, 18->1] runs successfully using sudo wolfram in the command line via SSH.

DeviceWritesuccessviaSSH.png
DeviceWritesuccessviaSSH.png322×118 6.53 KB

GPIO18_ON.JPG
GPIO18_ON.JPG1224×1632 435 KB

TL/DR
Has anyone else had success/trouble with the RDK, DeviceWrite and Raspbian Jessie?

2

Update:

I’ve managed to get BinaryWrite to work (from Arnoud’s instructions Using the GPIO with the Wolfram Language + Raspberry Pi ) via some buttons like this:

stream = OpenWrite[“/sys/class/gpio/gpio18/value”,
BinaryFormat → True]

Button[“flash LED”,
task = RunScheduledTask[{BinaryWrite[stream, 48], Pause[0.5],
BinaryWrite[stream, 49]}, .5]]

Button[“stop Flashing”, {RemoveScheduledTask[task],
BinaryWrite[stream, 48]}]

But, I have also noticed that "/sys/class/gpio/gpio18/value” doesn’t seem to exist until I run DeviceWrite[“GPIO”, 18->1] on the command line either.

to be cont’d…