This design was made as part of the Stulpe Circuit Project

To keep the circuit flexible, parts and functionality are groups into small areas with flexible areas in between. one option is to make the hard nodes from hard PCB material and solder wire connections in between (see photos). Another option would be to design a hybrid circuitboard that transitions between hard and flexible pcb materials. For this option it would be nice to have hard pcb nodes manufactured by fritzing. Their boards are white and most of the electronic parts are black. The black/white aesthetic would go well with the colours of the stulpe.

Modules…

Module string

On stulpe

Detaching

Comments and Observations

– In order to attach and remove the circuitboard from the snaps on the stulpe a considerable amount of strain is exerted on both the knit fabric of the stulpe surrounding the snap, as well as the snap mounted on the circuitboard. reinforcement backing added to the knit fabric helps relieve and distribute this strain on the side of the stulpe.
– There are a number of small components on the circuit and if the circuit is made super small then all these small parts end up very close together forming a firm surface, even if they are mounted on flexible circuitboard.
– Machwerk has had to move out of their space so i currently don’t have access to an etching bath. for now my options are vinylcut coppertape or lasercut copper fabric.
– A flexible circuitboard made of copper tape (vinylcut) or copper fabric (lasercut) is very fragile when bent and strained at the solder joints.
– Stulpe knit fabric is not very stretchy or tight fitting so sensors are not stretched/pressured much through bending the wrist up and down. Pressuring of the wrist against the surface of the table is most reliable.

Parts

– Male and female metal snaps
– ATtiny mircorontroller
– RGB LED
– Speaker (or vibration motor) — make the speaker coil directly on the pcb and just add magnet
– 2 pull-up resistors
– 2 Capacitors
– JST socket
– LiPo battery
– Slide switch
(- Programming pins)