I should add that the process of creating typed arrays can be quite slow (as Espruino has to search for a contiguous area of free memory) so if you want to get the best performance out of compiled code you're best off allocating them once, when the device initialises.
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.
I should add that the process of creating typed arrays can be quite slow (as Espruino has to search for a contiguous area of free memory) so if you want to get the best performance out of compiled code you're best off allocating them once, when the device initialises.