So i just opened the cad file, and umm doesnt look like we have alot of space down there… Are those gimbals really that thick on the back? so were you thinking about putting the board just under the screen??
As I mentioned, I would probably not be around much this weekend…
The current board is 3" by 2.6", the hole pattern matches all Lynxmotion boards… 2.7" and 2"
Been playing around some with SMD version, so far it looks like:
Can do some more cleanup… I also converted the 3.3v/5v conversion over to the same design that the Parallax boards use, so should be more robust that way…
Note: some of the 3d stuff above is off, I did not update the drawing stuff to use 7 pin versus the 6 pin for before… As I gave X6 (Extended Serial 6) a full 3 pin header.
Also trying to decide if I will also give X7 one as well with a default jumper to Voltage divider so you can remove it if you need 14 Analog inputs…
Looking at my previous post with the SMT packages, I felt like there was too much wasted space on the board. So I was trying to cram the stuff back into a standard Lynxmotion sized board. Decided that was not probably going to work so I split the difference. I was 2.6" wide, standard was 2.3" wide, got it down to 2.45"
While at it I also made the 8th extended Analog signal useable with a jumper that you can put for the voltage divider circuit… Gives you several options. If you don’t need a lot of Analogs, you can always jumper from voltage divider to any analog pin. Did not update the 3d models yet, so drawing is not right, but you should get the idea…
I want to make another pass through and verify my signals, especially with the XBee stuff that should be about the same as the Stuff that Parallax does. Then may order up some boards. Not sure yet from where, I am used to PCFabexpress, Or could try the service through Sparkfun, or the new beta PCBFabepress has the ability to order directly through Bay Area Circuits, which may be slightly more expensive then PCBFabexpress, but not sure…
Sounds good, Still doing some finishing checking of the schematic. Found a minor issue yesterday, where I connect up on LED slightly wrong (went through an extra resistor).
Will probably go for first round on this to a US fabricator where I can get it back in a reasonable time. Sounded like the one through sparkfun could take up to a month…
Cost for fabrication: If I go the route I have done in the past: PCBFabexpress, where I generate the Gerber and drill files, If I order 5 boards with 5 days the cost comes out to $75 plus shipping (no testing, no bottom silk screen…). If I go with the one that works directly with DipTrace (BayArea Circuits), their charge for this is about $22 per board under 10 for 5 days, but this also includes doing electrical testing and bottom silk screen, they have an option not to do the Solder Mask, which cuts it down to $18.38 per board.
As for parts, step 1, will be that I update my Parts list for this board… Maybe easiest if each of us order our own parts. Although that will probably imply that you have some extras as some small resistors have minimum order of 10… As I have done several different boards in the past I have several parts already in boxs. For some of these I could probably through a few in the envelope when I send one to you, but as you probably know they are not expensive…
As for Assembly, 1 or 2 will be hard enough for me, so probably best to let you solder your own, where your hands and eyes are probably a lot better at this then mine are . If later others want more boards, than it might be nice if someone actually produced the boards… Not sure if this implies solder paste and Toaster Oven or Frying pan, or if someone actually assembles them, not sure…
For myself, I have fun playing around with designing and building a board like this as I learn a lot and have fun!
However as a reality check, if one were interested in producing boards like, this, you have to ask yourself what am I gaining by building this board versus some other approaches. Lets say for now that to fabricate and build this board will cost you maybe $40-50 per board. Obviously if you fabricated in China and built lots, the cost would go way down.
But another approach would be to simply purchase something like an Arduino Mega for about $50, maybe use an XBee shield or simply use XBee adapter: $15-50… Plus here is that you have 4 USARTS (1 debug, 1 XBee, 1 Display), 16 Analogs built-in no multiplexer and code needed, lots of memory, standard Arduino setup… Downside is that there is no sound (possibilities here to get that), no 3 pin Servo like connections. But of course we are not plugging in any servos. So could simply wire all of the +5 and Grounds to each other for all of the switches and Joysticks and then simply connect each switch and like into their own IO pin… This approach again is not as clean, for wiring, but does have merit. Variation of this is of course you could wire all of the stuff into Arduino Mega Prototype shield or could use my shield with as much or as little populated in it as we need… Just throwing out ideas… No mater which way we go, will probably still order a few of the boards above to try, just for the heck of it.
I have included a zip file here with all of the stuff I will probably later today send off to PCBFabExpress as I am used to them… The zip file includes the Gerber and Drill files as well as the design files from diptrace. It also includes an Excel Spreadsheet with the BOM with Digikey parts… I need to take a quick inventory of what parts I have and make an order.
But as I said I keep running around in circles. I earlier choose the ATMega644p as it was a DIP that was easy to solder. Now that I went to SMD part with a lot of pins, I wonder if I should convert instead to Atmega128/256. This way I have 16 analog pins without trying, lots of IO pins, and 4 usarts… If I get a chance I may try a quick and dirty board…