CANxtra Capacitive Keypad

NETMF & Gadgeteer
21

Can’t see why not. You might have to adjust the sensitivity for the bottom pads, but that is done easily in the driver. Also, it will not fit into the recess in the case if it is 1.6mm.

Maybe look at something like this?
http://www.ebay.com/itm/PCB-Copper-FR4-Circuit-Board-025-x-12-x-36-/360377165921?pt=LH_DefaultDomain_0&hash=item53e8272861
It is 0.6mm double sided. Note: I have never bought from this person…

Or try this one:
http://www.ebay.com/itm/Copper-Clad-Laminate-PCB-Printed-Circuit-Board-Material-/120664289524?pt=LH_DefaultDomain_0&var=&hash=item61cb107fa2
You can select double sided 0.13mm or 0.2mm. Looks interesting. Might try that shop at some point…

The stuff I used isn’t really specialized, just might not be easy to come by. I think they use it to make multilayer boards.

22

Nice job. I was actually thinking about making a keypad using something like this: [url]https://www.adafruit.com/products/419[/url], but you solutions seems more elegant :slight_smile:

Might have a go with the double sided 0.13mm from the link you provided ([url]http://www.ebay.com/itm/Copper-Clad-Laminate-PCB-Printed-Circuit-Board-Material-/120664289524?pt=LH_DefaultDomain_0&var=&hash=item61cb107fa2[/url]).

Btw I use trace paper for manufacturing PCB as well.

23

@ lauszus - I also thought the adafruit keypad would be good for the CANxtra, but it doesn’t quite fit. A little too big, so would require some trimming. The traces don’t come anywhere near the edge of the pad, so it might just work with some precision Xacto knife cutting skills.

24

Yeah exactly. Not sure which one I will go for yet :confused:

25

The only problem with that keypad, that I can see, is the exit point for the cable. You will have to cut a new slot in the case of the CANxtra and mangle the cable once inside. But if you can get it to the connector then it will plug seamlessly into the CANxtra.

I made this capacative one so that I can overlay any button face that I want. If I use it for 3D printer then I can place X+,X-,Y+,Y- etc keys on it. If I use it as an CAN tester then I can place a 0-9,A-F keypad on. ETC… :slight_smile:

26

Okay i think I might have a go with yours if I got the time :slight_smile:
I am still a bit unsure how your made it. Could you just make one from a double sided PCB and the make a via yourself?
Could you maybe post some pictures of the manufacturing process?

27

OK, it’s time I need to ask the hard question… how did you get the QFN onto your circuit board? Did you do a proper reflow in an oven (toaster oven?), or did you just hit it with a soldering iron somehow, or did you use a hot-air reflow tool? I’m in need of knowing :slight_smile:

28

If you make the pads big enough then you can solder it with a fine tip, but it isn’t fun. I used a hot air smd station… :slight_smile:

29

Thanks GMod, looks like a quick trip to eBay is in order :slight_smile: