µBotino - 2"sq board for robotics, Arduino compatible

By Ro-Bot-X

September 3, 2010

After playing with the Robot Builder's Shield, I've decided to make a small robot board that has the same features as the shield. I wanted it to be 2"x2" (5x5cm) so it can be fabricated cheap and to be appealing to many robot builders that still build small robots.

I present the µBotino robot controller. Features:

6 analog sensor connectors
5 servo connectors
SN754410 H-bridge, digital pins 5-8
6 digital sensor connectors
3 pin hardware serial connector
Arduino FTDI cable connector for programming
6 pin ISP connector
reset button
jumper J1 to select power (5V or Vin) to the servo connectors
jumper J2 to enable/disable power to the motors (you don't want the robot to run all over when programming)
jumper J3 to enable/disable the LED on pin Digital 13 (don't use the LED when using a servo)
16 MHz ceramic resonator
power LED
power switch
5V LDO voltage regulator (1A or more)
small form factor, 2" square

Using Fusion PCB 2layer 5x5cm service from SeeedStudio, 10 boards will cost $20 to make. That means $2 a piece! I think all parts plus the board can fit a $20 bill.

Here is a picture of the PCB:

Update 04.03.2010: Order placed at SeeedStudio. Can't wait to work with them! Perfect for a Start Here robot!

Here is the schematic (click to get a bigger image):

Update Sept. 23rd 2010.

I got the boards in the mail! Here's how they look like:

I can sell the µBotino PCB for $4 USD. I will get back soon for a complete kit.

Part list from SparkFun:

Total price: $27.7 USD with 2 items that are not what they should be. I hope I can get better prices than this!

Update, Sept. 24th 2010:

I have populated the first board and uploaded the code using the xBees. I had to set up the baud to 19200 because I used a mega168, but it worked flawlessly. Now all I have to do is mount the board on a robot and take a video...

Pictures:

More to come...

Update Sept 25th 2010:

Installed the µBotino on my daughter's robot and took a video. Enjoy!

Update Nov. 12th, 2010:

New boards are in stock and ready for sale here:

http://robotxdesigns.ca/2010/11/08/the-ubotino-v2-pcb/

and kits:

http://robotxdesigns.ca/2010/11/08/the-ubotino-v2-kit/

Update April 16th, 2011:

I am getting low on the boards in stock (only 4 left) and I am looking to make some inprovements to the design. So, I am getting at version 3:

- replaced the SPDT sliding switch with a DPDT toggle switch - taller, easier to work with; the switch (in the Off position) separates the voltage regulator from the servo and motor power bus so there is no power leakage during programming with the FTDI cable

- moved the power connector between the voltage regulator and the power switch

- removing jumper J2 removes power to the servos and the motors at the same time (useful in case of debuging code)

- removing jumper J1 removes the power only for the servos

- added an extra 2 pin unkeyed connector in case one needs separate motor and servo power, remove J1 if used

- moved the D0-D4 pin names on the silk screen closer to the pins, for a better understanding

Here is the new schematic:

Here is the new PCB layout:

Let me know what you think.

Update May 21st, 2011:

I have received the new boards today and I am glad the custom part I designed in Eagle for the DPDT power switch fits perfectly. Can't wait to test them out, but I have another package on the way with male header pins and the Arduino long leads female headers for the shield. As soon as I can test the boards I'll add them to the store so you can get them. The new improvements make them easier to use and a better product.

Here are some pics:

I hope you'll like them!

Embedded video:

Attachment	Size
Bot4Julia.pde	9.29 KB
Speaker.zip	1.36 KB

By Ro-Bot-X
@ Sun, 2011-05-22 01:30

I got the new boards, see

I got the new boards, see the update!

By Ro-Bot-X
@ Sun, 2011-04-17 20:30

Updated version 3 of the

Updated version 3 of the design...

By ignoblegnome
@ Mon, 2011-04-18 16:11

I like the changes. More

I like the changes. More options are always nice (at least to me).

Is there room on the reverse side of the board to include a description of each of the jumpers? More options can also be more confusing. ; j

By Ro-Bot-X
@ Mon, 2011-04-18 23:09

I'll try to do it on the

I'll try to do it on the ground plane, as a bottol silk screen adds to the cost and we don't want that. However, it's hard to give a short and complete list of options.

By rik
@ Sun, 2011-02-27 21:59

Question about programming through serial port

I asked here how I program this board through an old fashioned serial port.

By rik
@ Mon, 2011-02-28 21:54

Serial pins

Devilish detail: the pin between GND and Vcc is not connected to anything, right?

By Ro-Bot-X
@ Tue, 2011-03-01 01:57

You're right. That pin is

You're right. That pin is CTS on the SparkFun's FTDI basic board, so there was no reason to connect it to anything, since it's not used. You may solder it to GND on the back of the board, if needed.

By rik
@ Tue, 2010-11-23 21:03

Finally a webshop that does proper wishlisting!

Sparkfun recently introduced wish lists to their webshop. This list http://sprkfn.com/w986 holds all 20 items Ro-Bot-X mentions in the OP. If you are interested in shopping all these items in one click, just hit that link and throw ll of them in your basket. Remove the items you do need to buy.

NB: Sparkfun still has no through hole version of that reset switch, nor an LDO version of the LM7805 in its catalogue. I also changed the Atmega328 to a version with Arduino bootloader.

Also Nota Bene: This list lists for $29.85 as I am writing this today. You would be better off buying he kit (board included) from http://robotxdesigns.ca/2010/11/08/the-ubotino-v2-kit .

I am just so happy to have found this wish list system. I hope it also works anonymously. Let's find out.

Finale Bene Nota: Do not end these items to me. I'm all set.

By Ro-Bot-X
@ Wed, 2010-11-24 02:22

Be advised that SparkFun

Be advised that SparkFun does not have the LM2940-5 LDO voltage regulator. The only items I get from SF are the ATmega328 blank (I load the bootloader myself) and the SN754410 H-bridge. All other parts come from Digikey and other suppliers. That is how I manage to keep the price lower than SF's. I make almost nothing from the parts and only a little from the boards. I just wanted to provide a service to other people so they can get everything from a single place. Unfortunately I can't do that with other robot parts, like motors, wheels, sensors. They need a bigger investment that I can handle at this time. Oh well...

But I have a few other boards in mind...

By Ro-Bot-X
@ Wed, 2010-09-29 02:47

I have attached the sketch

I have attached the sketch and the Speaker library if someone wants to give it a try. I have also updated the board and schematic pictures with the part values for the resistors and capacitors.

µBotino - 2"sq board for robotics, Arduino compatible

Comment viewing options

I got the new boards, see

Updated version 3 of the

I like the changes. More

I'll try to do it on the

Question about programming through serial port

Serial pins

You're right. That pin is

Finally a webshop that does proper wishlisting!

Be advised that SparkFun

I have attached the sketch

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