Bot4Julia.pde (9511Bytes)
Speaker.zip (1395Bytes)
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:
2x https://www.sparkfun.com/commerce/product_info.php?products_id=116 pin headers
4x http://www.sparkfun.com/commerce/product_info.php?products_id=8375 cap 0.1uF
1x http://www.sparkfun.com/commerce/product_info.php?products_id=315 SN754410
1x http://www.sparkfun.com/commerce/product_info.php?products_id=9650 LED green
1x http://www.sparkfun.com/commerce/product_info.php?products_id=533 LED red
1x http://www.sparkfun.com/commerce/product_info.php?products_id=102 power switch
1x http://www.sparkfun.com/commerce/product_info.php?products_id=8229 reset button (this one is SMD, should be TH)
2x http://www.sparkfun.com/commerce/product_info.php?products_id=96 cap 100uF
3x http://www.sparkfun.com/commerce/product_info.php?products_id=523 cap 10uF
1x http://www.sparkfun.com/commerce/product_info.php?products_id=8374 resistor 10k
2x http://www.sparkfun.com/commerce/product_info.php?products_id=8980 resistor 1k
1x http://www.sparkfun.com/commerce/product_info.php?products_id=9061 ATmega328
1x http://www.sparkfun.com/commerce/product_info.php?products_id=9420 resonator 16MHz
1x http://www.sparkfun.com/commerce/product_info.php?products_id=7942 28 pin socket
1x https://www.sparkfun.com/commerce/product_info.php?products_id=7938 16 pin socket
3x http://www.sparkfun.com/commerce/product_info.php?products_id=9044 jumper
1x http://www.sparkfun.com/commerce/product_info.php?products_id=107 5V v-reg, (this one is regular, should be LDO)
1x http://www.sparkfun.com/commerce/product_info.php?products_id=8233 power connector header
1x http://www.sparkfun.com/commerce/product_info.php?products_id=8100 crimp pins for power connector
1x http://www.sparkfun.com/commerce/product_info.php?products_id=8095 power connector housing
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!
https://www.youtube.com/watch?v=jtR88ssGZP8?hl=en