It might help if you changed this.spi.send([c,c,c,c,c,c,finalClk]); to this.spi.send(new Uint8Array([c,c,c,c,c,c,finalClk]));?
this.spi.send([c,c,c,c,c,c,finalClk]);
this.spi.send(new Uint8Array([c,c,c,c,c,c,finalClk]));
@Gordon started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
It might help if you changed
this.spi.send([c,c,c,c,c,c,finalClk]);
tothis.spi.send(new Uint8Array([c,c,c,c,c,c,finalClk]));
?