Nice progress. Make sure to make some awesome videos once you have made enough progress.

I love the table, by the way. It looks exactly like the lab tables in my electronics class lab. I also like how in some pictures, you can see a desktop keyboard, and then in the latest picture, you can see it's clearly transmuted into a laptop.

Also, I'm wondering what you are planning to do for the "threshold circuit." I don't have enough experience yet to know exactly what you are going to do there (if I should be able to figure that out from this much information, that is), but that is definitely the one part in your diagram that I wouldn't know how to build by myself without a schematic or guidance. Once you get around to that part, be sure to explain what you did so that the rest of us can replicate it.
Here's the quickest and dirtiest I've come up with schematic-wise. The 27K and 3.3K on the top circuit will need to be tuned to set the pixel detection threshold. Also, check out the second picture, a picture of my desk in my lab. The laptop you see is the lefthand tablet PC on the second tier, Prhh, undocked and unfolded. Smile



[click to enlarge]
As best I understand it, cleaned up in EAGLE:

Oh, I see I forgot values for R4 and R5. Oh well, it's just a little prettier to look at.
Very nice, Tari, that's exactly correct. Thanks for cleaning that up for me. Smile
How did this go? Did you get the hardware to a point where it could be interfaced and programmed, Kerm?
Good question, I meant to dig this topic back up a few days ago because I noticed it wasn't very active anymore...
magicdanw wrote:
How did this go? Did you get the hardware to a point where it could be interfaced and programmed, Kerm?
Oh yes, I meant to post updates. Interface hardware is awesome, physical hardware is all good, software is pending, and the only sticky wicket is that I'm trying to perfect the IR illumination so that I get a consistent threshold on the pixel on/off issue.
*bumpity bump* Drilled and tapped a lynchpin, tried inserting it, heat-shrank some tubing around the light sensor / touch button assembly, tested everything and discovered that although the button works fine, the light sensor is being really shoddy. I'll have to break it down and check out why the light sensor is being a pain, and in the mean time I'm working on some software for it.
Awesome! Good to hear an update Smile

Also, I hear there are pics on the way? Very Happy
maybe you should acquire and disassemble one of the old RCX light sensors.
swivelgames wrote:
Awesome! Good to hear an update Smile

Also, I hear there are pics on the way? Very Happy
OK, light sensor is back online, I was just testing it using a retarded method. Time to finish the driver so I can calibrate out the board and put the pen together. I might run into some more issues with the LCD flare that happens when you press the screen, but I'll deal with that when I get to it. Pictures as soon as I re-shrinkwrap the pen, which should be tomorrow morning.

Edit: here it is! Pictures in the morning, and I'll also try to work on the board layout. Now I need to get back to work. Smile The background colors on the board are just to show trace continuity; red lines are trace cuts on the vero board, and the orange is a solder jumper. In theory this board is 0.32" by 1.5" and fits within the circular cross section of the pen, but I'll need to experimentally verify that.

Looks cool!

There you go, Kerm.
foamy3 wrote:
Looks cool!

There you go, Kerm.
Very Happy Thanks Foamy. Smile Actually, more specifically I was hoping someone might quickly check that I transcribed it correctly and didn't accidentally leave anything shorted or missing.
Oh, haha, I thought you just had more pics and didn't want to double-post. My bad.
KermMartian wrote:


lol 2008
Eh, close enough. Anyway, started to build this today, and I ended up cheating and using SMT resistors and an SMT indicator LED, which saves me a lot of width. Note how much I have to trim the sides of the board, but it still works. I am going to try laying out the transistors on the other side, then solder on temporary wires for the 3.3K and 27K resistors to fine-tune calibration.


Click any image to enlarge
Final product?
Ultimate Dev'r wrote:
Final product?
I got distracted by a whole bunch of assignments, but I should solder the four transistors I have threaded through the board on and start testing resistor values.
  
Register to Join the Conversation
Have your own thoughts to add to this or any other topic? Want to ask a question, offer a suggestion, share your own programs and projects, upload a file to the file archives, get help with calculator and computer programming, or simply chat with like-minded coders and tech and calculator enthusiasts via the site-wide AJAX SAX widget? Registration for a free Cemetech account only takes a minute.

» Go to Registration page
Page 3 of 3
» All times are UTC - 5 Hours
 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

 

Advertisement