chalky - street chalk printer

very first test done, works, but needs finetuning

things to fix:

- fine tune nut settings, each can seems to deliver a different amount of chalk

tomorrow starts gulasch programmier nacht gpn15. maybe i should go and finetune there.

should probably be higher (for bigger dots) but lets test that first

forgot front view

basically only an rotation encoder (like used in ultipanel), ball bearing, m4 screw and cutted foam. looks unfinished, but works. pulls pin 2 of the arduino to ground if bike moves (internal pullup of pin 2 is on, so no external pullup needed).

left 1st version, right final (3rd) version

mounted to my dog trailer

one of our cats likes the dog trailer too

mechanical and electronics done, no software yet.

also: old lipo=dead. old lead accu=dead. bought a new 12V 4800Ah 2.6A current lead accu. works.

the solenoids:

spraycans mounted

test firing made a mess on my bench

the (simple) electronics: mosfet, opto coupler, 2 resistors, 1 protection diode per solenoid. see fritzing sketch for compontent list.