Puck.js with Node-RED on Raspberry Pi

Are you sure you disconnected the IDE from the puck before your attempt? I can't get mine to work at all but it's a different set of errors.

Another problem is I believe your string is too long. I believe 20 characters is the limit.

You could type this function into your puck (remember to disconnect after):

function x() { digitalPulse(LED1, 1, 100); }

and then change your mqtt message to "x();\n" just to try it out