Custom PCB

[s_alaniz]

In my opinion, page 13 of the rules says that "inputs to the circuit board may be.....optical sensors, motors and OTHER SENSORS ALLOWED IN THE ADDITIONAL HARDWARE LIST." And since components that could be used as sensors are availible from Digi-Key I would assume they could be external to the PCB. So an optical sensor purchased from Digi-Key can be placed on a wheel, arm or other part of the robot and wired back to the PCB board.
At least that is how I would interpert that section.

( Don't be wimps.... etch your own PCB!!!)

Steve Alaniz (Mentor)



"..you're saying we can look forward to robots demanding higher saleries and behaving badly..." - Sally Forth

[Kai Zhao]

How would you etch your PCB?

I have previously read some stuff on etching PCB and used a small breadboard a few times but I never really etched PCB.
Would you use FR4 (not like I have any idea what it is) or a Copper Clad Board to etch?

Would a prototype board be better?

[s_alaniz]

OK, I was joking.... etching a PCB is not for the faint of heart. I understand the San Jose guys really pushed for adding PCB and I suspect other people who had access to professional facilities also liked the idea. I do too, but I'm just a hobbiest from WAY back and I've ruined quite a few shirts from etchant.
You can get a copper clad board from Digi-Key or Radio Shack, draw or dry transfer your circuit pattern on the PCB, drill the holes for the ICS and wires, (there's also a photo etch method but you can't see where to drill the holes...) pour either Ferric Chloride or Sodium Persulfate or Ammonium Persulfate in a PLASTIC or GLASS tray, place your PCB in the solution and rock it for about 20 minutes or until the solution has etched away all the unwanted copper, clean the copper with fine steel wool and VIOLA! (Luck helps here.. sometimes you etch away a WANTED circuit line if you're not careful) Now all you have to do is figure out how to properly dispose of the spent etchant...
OR... you can WIRE WRAP the circuit on a perf board. (Don't laugh... I wire wrapped an entire clone FIRST controller system in 1998...also not for the faint of heart or anyone who has a life!)
If you're STILL heck bent... go to the library and check out the December 1989 copy of Radio-Electronics and build the tank system they suggest... for NEXT year.

Good Luck!


Steve Alaniz


"Yeah those robots are cool...but If you can't play Nintendo on them... what good are they?" - Hilary Forth