I think if you want some help you'll need to post up the code you're using, and what error messages you get (if any).
Thinking about it, you may have some difficulty using both network interfaces at the same time - Espruino is only set up to use one.
Still, you should be able to use just the AT commands with the SIM800 without those problems
@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.
I think if you want some help you'll need to post up the code you're using, and what error messages you get (if any).
Thinking about it, you may have some difficulty using both network interfaces at the same time - Espruino is only set up to use one.
Still, you should be able to use just the AT commands with the SIM800 without those problems