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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.
@Hardware_Hacks
Those extra characters you are seeing seem very similar to the issues I had when I was using GSM modules. The root cause was power. The board needed 5v and also the correct current spikes which I think went up to about 1.4A, ensure your power supply can support this high spike otherwise you will keep getting these messed up chars. Once the power works correctly you often find all the old commands will run through the module also as if they are blocked up so always good to disconnect everything for a few seconds.