Let's Make Robots!

LMR series of PCB's

I think that LMR should have its own series of circuit boards, with the designs open source for all LMR'ians to use. Heres a couple ideas for PCB's:

  • SN754410 Board
  • Small Encoder boards
  • Various control boards for PIC, PICAXE, AVR, Arduino, etc

After finally getting a decent laser printer, i'm able to produce PCB's of excellent quality with traces as small as one hundredth of an inch. There are of course minor flaws but all boards are operationally sound. I am willing to produce PCB's for all LMRians for very, very low prices, and circuit test and a microscope evaluation of the board. I can even solder on any SMD components if needed. I guess what this forum is about, is ideas for PCBs for LMR'ians. I have created a couple boards already that I can post, such as a couple PIC controller boards, a Motor Control board and a Li-Ion battery charger board.

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Voltage regulator board, compatable with 78xx regulators. 5$ per board, made out of red PCB material and exactly 1 square inch :)

ignoblegnome's picture

I'd rather see a LDO voltage regulator on the board than the 78xx series.

Some dude named Krumlink asks about some alternatives in this post on http://www.electro-tech-online.com/datasheets-manuals-parts/32193-ldo-replacement-7805-a.html.

You can solder different values of capacitors into the board to meet the requirements of the LM2940, a .47UF capacitor on the input and a 22UF capacitor on the output. Also, I would replace the diode (in the board) with a jumper to avoid the 1.4V drop, to ensure you can run the regulator at 5.something volts.

4 Years ago, things change..

Anyways a L2940 is a LDO that is compatable with the 7805, Will work the same, compatable too, just use a tantalum capacitor instead of a monolithic disc capacitor.

voodoobot's picture

Worked on a lipo charger with usb and external input(solar) connectors. 3.3v Reg onboard supplied by battery or external power(usb through charging unit). Will work on the layout today. First smt project...so we'll see how it goes. Similar to the SF setup(uses the mcp) only the vreg chip is set to specific voltage looking to set it up to fit in some small cases that I have. Not sure how useful they will be to others as they are ment for low power systems, with specific focus on it being used with an msp430 chip. Still, someone might find it useful as well.  :) 

Heres the second revision of the SN754410 1A motor driver:

 

Note The Little LMR bot and the backwards lettering, all to be fixed in 2.1.

 

 

With revision 2 comes pulldown resistors (optional when you assemble the board) and the board is optimized for multiple boards. This means you can stack multiple SN754410 boards together! Simply assemble them as usual but use wire wrap headers instead, and it allows stacking of the control lines. All it then needs is a wire jumper for reach motor terminal. This board (revision 2.1 will fix backwards lettering) Will sell for 15 dollars assembled, excluding shipping.

Ro-Bot-X's picture

The boards need a LMR logo easy to do on the copper. Is someone working on that?

webmaster's picture

I tried to make that logo (from "about"-page, top menu, you can find all logo in vector) - but our logobot is just not cut for small print IMO. Someone shoudl have thought of that :)

However, though logo's look good, I think the link to the page where the board is discussed / comes from will be of much greater use. And that goes well in small resolutions.

We can always throw a LMR  on the board :)