@Osch Kind of hard to splice small gauge wires without soldering or terminals. A step towards wire splicing without soldering is to buy a wire stripper suitable for small ~20-28 gauge wires like this: • Small wire nuts (probably the purple ones for 20-28 gauge or so). Requires wire stripper. Just cut jumper wires in half, strip, and twist up 3 or more for more grounds. Wire nuts make excellent connections, maybe use electrical tape to wrap them if there is any concern of tugging on the wires. • No-strip insulation-displacement connectors aren't likely to work with the tiny stranded wire in your jumpers. • Crimp splice connectors like used for telephone wire splices might work but then you need a decent crimper, although a pliers may do. May be too big for smaller wires. • Screw terminal blocks can work well for wiring to sensors if you have a place to anchor the block. Tim