I was told that the Arduino name is trademarked so I can’t use it without paying a license and have the written approval from the Arduino team. I mistakenly thought that if the word Arduino is used in conjunction with other words is ok. So I have changed the name of the board to Robot Builder’s R-duino. I will order new boards with this name and also with a few other improvements in the following week. Until I get them in stock, no kit will be sold that contains boards that wrongfully use the Arduino name.
Apologies to the Arduino team and thanks for understanding.
I finally had time to finish up the assembly guide for the RBA kit. Phew!
One big observation: the first batch of 10 boards have the Tx and Rx pins not swapped, so if you plug in the FTDI cable the board can’t be programmed. For this reason, the first 10 customers will receive for free an adapter that swaps the pins. All you need to do is plug the adapter into your FDTI board or cable, then plug the female part of the adapter into the RBA board. This bug will be corrected in the next batch.
Here is a picture of the assembled board:
And here is my LMR Start Here Robot with the RBA on it:
I’ve been asked, even though there are plenty of similar products out there, to make a board that combines the Robot Builder’s Shield with the Arduino. Make it the same footprint as a regular Arduino board, but keep the same features of the RBS. I said, why not use the µBotino? Well, because is not shield compatible. People want to add other shields, like a color LCD shield, or an xBee shield. So I started to fiddle around and see if I can cram everything I wanted on the same board using TH (through hole) components. Not everything I wanted got there, but most of the stuff made it. Sure, I want a board that satisfies all needs, but that would make it bigger (and there are plenty out there like that) or use SMD. So here is what I got done:
- same size as a regular Arduino board, with 3 mounting holes,
- 6 servo connectors (selectable power – J1, digital pins 8-13),
- 6 sensor connectors (regulated 5V, all analog pins),
- a SN754410 H-bridge (1 amp per motor, digital pins 4-7, uses Timer0 for PWM),
- screw connectors for motors,
- pins 2 and 3 (external interrupts) available for encoders,
- a FTDI connector (to program the board using a USB-serial cable),
- a ISP connector (to program the board using a hardware prorgammer),
- polarized Molex connector for the battery (4.5-12V, no more than 6V if you use servos),
- 3A LDO voltage regulator,
- reset button,
- pin D13 LED,
- power LED,
- power switch,
- all Arduino female pins are doubled with male pins, arranged to allow easy prototyping shields,
- filtering caps near the sensor and servo 3 pin connectors.
J1 is to select power to the servos, either regulated 5V or directly from the battery.
J2 and J3 are to select the motor control mode, either 2 pin mode (Enable High, one Dir for PWM and the other for direction) or 3 pin mode (PWM on Enable, 2 direction pins). In 3 pin mode, 2 I/O pins allocated for servos are routed to the motors, so you end up with 4 servo connectors available. The LED on D13 has no selecting jumper, so it will flicker when a servo is connected to the same pin.
One more thing, the board does not have a 3.3V regulator, so even though the 3.3V pins are in place, they are not connected to anything and do not provide power for other shields. I don’t think I can cram in a TO92 regulator in there…
Here are the pictures of the PCB layout and the schematic, the blue is the bottom copper -GND plane, the red is the top copper – 5V plane. Round pins are male, oval pins are female (click for a larger image):
I have ordered 10 boards at SeeedStudio, they should arrive in about 3 weeks. The parts should arrive sooner, but after Canada Post’s strike, mail is backed up and it seems forever until… oh, the parts come by FedEx, never mind… Yeah… Can’t wait to test one!
After a few days of hard work, taking pictures and writing the new assembly and usage guides, a bit of testing and adapting the code for the new features of the RBS, the products are in the store. Now I can focus on the other projects…
Pictures of the assembled boards:
You can find the guides on the Downloads page from my store: http://robotxdesigns.ca/
I have received today the third version of the Robot Builder’s Shield and the µBotino controller from PCBcart. They look as good as the second version and so far I did not discovered any mistakes (silk screen related or miss placed holes…). The DPDT switch part I designed in Eagle came out good and the switch fits perfectly in the holes. So far, it’s all good. I have to assemble a board (of each) and test it out on a robot before I put them in the webstore. Also, I am still waiting for the long leads female headers for the shield and a big bundle of male header pins, probably during the following week they’ll be here. So, just a wee bit of waiting and you can get them!
Here are some pictures:
And here I put some parts on the µBotino board to see how the changes look like:
The µServotino is next, I was just waiting for confirmation that the power switch fits perfectly, didn’t want to order more boards and have problems. These boards will come from Seeed Studio this time and they will have white silk screen, as they offer black silk screen only for white boards. Sorry for the delay, but I don’t want to get bad boards.
I have only 1 RBS v2 in stock and 3 µBotino v2. I have ordered new boards, but it will take about a month to get here from China. But the new boards will have some improvements:
The Robot Builder’s Shield V3:
– added jumpers for the user to set the control mode for the motors, either 2 pin mode like the previous version, or standard 3 pin mode, at the expense of losing 2 servo pins
Schematic and board:
The µBotino V3:
– replaced the SPDT power switch with a DPDT switch so the servos and motors do not get power that leaks through the voltage regulator when powered through the FTDI cable
– repositioned parts on the board, mainly swapping power connector with power switch positions, moved J2 near J1
– added 2 pin header for optional different servo power than for the motors, remove J1 if used
– moved some silk screen text to be easier to understand the pin name/number for the lower part of the board
Schematic and board:
Things that were too difficult (or impossible in the current format) to do:
The RBS V3:
– could not separate the power for the motors from the power for the servos
– did not add a LDO V-reg to replace the Arduino 7805, if one needs it, can do it in the prototyping area
The µBotino V3:
– did not have enough space to add motor control mode selection jumpers like I did to the RBS V3
All things considered, I think I’m at the last version of these boards, no more modifications, unless some stupid error comes through. I hope not… Now it’s µServotino’s turn to get a new version.
I made a new robot controller, called the µServotino, that allows a user to build a legged robot that uses up to 12 hobby servos.
- 12 servo connectors, with power directly from the battery, digital pins D2-D13;
- 6 sensor connectors, with regulated 5V, analog pins A0-A5;
- UART connector, GND, Rx, Tx, plus adjacent 5V and GND for each signal pin;
- ISP connector;
- FTDI connector;
- Reset button;
- power switch and LED;
- D13 LED, can be disabled by removing the J1 jumper;
- screw terminal connector for battery;
- low dropout voltage regulator, allows 6V batteries.
Here is the schematic:
Here is the PCB layout:
And finally, here are the pictures of the board:
Compare it with the µBotino:
Latter I’ll upload a picture with the board assembled and the first tests.
Ok, here’s the assembled board:
And here’s what you can do with it:
Tests after I’ll upload the bootloader…