My lcd+backpack I used for my controller https://www.robotshop.com/letsmakerobots/node/27429 falls right into that price point. It uses an Arduino, has a FTDI port, I2C breakout, and digital pin 9 and 10 broken out for use with the newsoftserial library and of course has some power and gnd pins around. It also has a pot for adjusting the contrast. Not saying it is in the perfect state, but it could do what you say right now.
Here's a super simple, easy encoder board. Use it for motors, Line following, floor sensing. Uses the super common QRD1114. Ready for purchase as single board or completely populated now!
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.
Yes, the logobot does not make for a good silkscreen but it might work. The bigger the better of course. This is a standard 50% threshold bitmap @ 200x200 pixel res. version of the bot (1" square):
this one is 1/2" square
The 1/2" looks real small in EAGLE, but hey, something is better than nothing!
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.
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. :)