lines starting with a 'greater than' denote quoted text return anything? That's the raw data from the sensor - it's possible it thought it wasn't against your skin, but for some reason hasn't been able to turn itself back on
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.
the issue pointed by @myownself is about that too