In my #testcraftcamp session on testing applications for embedded devices I got really good feedback especially into making the application more observable and use approval testing to validate its behaviour. Also @emilybache CukenFest talk was recommended: https://fast.wistia.net/embed/channel/gicldp4m47?wchannelid=gicldp4m47&wvideoid=s69d6v0lmw