Robot building


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Hello, greetings to all robot builders, I am eager to receive the board ez-b, to give life to my butler robot, robot weighing 2.5 to 3 kg, the wheel servos are 15kg of torque, modified for continuous rotation, arms and head as well these servos, body materials are cheap and easy to find, I have a lot of ideas for the project that I'd like to share. Ping 3 sensors and 1 sharp infrared, head with 2-axis motion, arms opening and closing hands, voice, etc. .. And all thanks to the fantastic product ez-b, which by its ease and flexibility, have encouraged me with this project, since my childhood I came in my mind. Here is a video with the current assembly.

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That is wicked cool!! Building the robot from a garbage bin is genius. The arms are great also. Where did you find the arms?


The arms are toys shop in Spain: Toys 'R' Us Price $ 6. They are easy to modify, and hands are empty, ideal for installing any pressure sensor, if you find them in Canada I can send you some, here is a mountain of robot arms in the store.


The project is moving forward! I tested the main features of the ez-b on my robot, and make a perfect marriage! This is just the beginning, the vision and speech, as well as other tricks are in future project. Very good, DJ Sures, I'm having a good time! Good job!



LOL This robot is absolutely cool! I really like the originality and custom build. He has a great personality:)



That is an amazing custom build. What tools and materials did you use and how much did they cost?


Sorry so long to answer, I've been offline a while, the total project cost is 270 dollars (to date) included ez-b board, servos, sensors, battery, LEDs, cables, swichs, and his body, bucket trash and a bowl (plastic), some aluminum and bolts, etc.. Tools: soldering tin hot glue gun, Cutex, and the best and most useful of all: the reamer radio control car bodies, is a sharpening and rotating for 1 to 15mm holes in plastic, but works on thin aluminum, wood, rubber, etc. This tool will recommend it to all robot builders have to work in plastic, this is: html


Hi robot builders! I hope to help or inspire other builders, the latest progress on my robot. Collision sensors in the lower body and a new ultrasonic sensor. When browsing the home is a small object or low-rise, the head sensor does not cover this need, this fixes the problem.

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I created two small programs in sensors to detect collision left and right, change the path of the robot.

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The ultrasonic sensor lower on the radar is set to change course . current setup ARC:

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Greetings from Mallorca, Spain.


Congratulations! This really looks good! You really made it look polished and not from a garbage can at all! I LOVE IT!


Glikclik Thanks! sometimes build a robot from scratch is not complicated, and find inexpensive plastic containers, and there are many sizes and colors. Add more progress soon: Bluetooth external antenna and battery voltage indicator! greetings.;)


Try these circular LEDs.:) Its different. Glik here

Maybe some multicolor EL wire lights under the brain dome. :}


R2D2, thanks for sharing all the info on your bot! I believe you were the first to post about your project in these forums and have probably inspired a lot of people with their designs, keep it up with the great ideas! I don't think I would have ever thought of using such common products such as a garbage can in my project, but after seeing your bot I will always consider it from here on in. Thanks again for your contributions!


Bluetooth external antenna. I had problems reaching the robot to turn the hallway of the house was lost wireless signal, then connect an antenna of 2.4 GHz with a piece of coaxial cable (50 ohms) 30 cm long in my case, only the inner cable to the antenna and Bluetooth circuit, cutting the original track integrated antenna with a knife. The theory says that the outside cable must be connected to the negative pole to the coaxial cable does not act as an antenna, I have not only the inside and it works. the extent of signal has been multiplied by 4! 4 to 16 meters! Now the robot can move around the house without problems radio signal.

The voltage meter for Li-Po battery is cheap and you can find for example here:

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Dude that is awesome!!!


The wavelength of 2.4 GHz is 125mm, a length of cable that connected to the coaxial cable length and the outer area of the robot, is enough, I understood a piece of thin wire wrapped in plastic. I hope that our robots may soon neighbor's house and further away!


OMG you guys are brilliant:) I love it!


R2D2, How did you wire the on off switch for the voltage regulator? The Bookmaker wants to know.


I have it connected in series with a power cable (not in parallel between the two wires) The red wire or the black (from the battery and ez-b,) you cut and insert the switch, and voila!


Hello R2D2, I already have a switch on the hot lead form the battery to the EZ-B however it does not control the voltage regulator which is pluged directly into the battery balance plug. How did you wire the voltage regulator on off to the on off of the EZ-B?


Bookmaker Hello, I suppose that when you write voltage regulator, you mean the voltage indicator three digits, only shows the voltage, but does not, then the switch is connected to the black wire lipo balancer connector with an extension male-female balancer the operation is safer for the battery, the black wire is common to all elements of the battery. Hope this helps you, greetings.


Thanks R2D2, I kind of came to the same conclusion. I ordered the extension since my local hobby store didn't have one. I assumed the black ground would be the one to switch and thanks for confirming.


R2D2, I am not very electronic savy so excuse my ignorance. Can i use 75ohm TV cable I have laying around or does it have to be 50 ohm for the extension antenna?

United Kingdom

Bookmaker If its a short run of cable it won't make a lot of difference 75ohm is just a bit thicker and not as manageable. I want to try this as well so let us know how you get on and if it improves the range


Hey, better if 50 ohm, 75 ohm cable also improves the scope, but not being of its impedance, I can not guarantee the survival of the Bluetooth module, part of the emission power back down the cable into the circuit, because it radiates all the power (SWR) ratio waves. I think for the price of a piece of 50 ohm cable (RG58) in my case, not worth risking the physical integrity of the bluetooth module, plus a further performance boost.



R2D2, Thanks for the input. I will get some 50 ohm.


I contacted a large manufacturer and asked for the sample department and my 50 ohm is on it's way. Free item, free shipping.


I received my free sample. It is almost 1/2 inch thick and totaly unusable. Does anyone have a source for some flexable comparatively thin 50 ohm coax? I have run the gambit to no avail. Any help would be greatly appreciated.


It sounds like you received RG213 which is also 50 ohm. You need to be sure to get RG58 which is what you're looking for.


R2D2, I now have two EZ-B's. Can I just put a Y in the antenna cable and feed both with one antenna?


R2D2, Wont he ruin the receive section on one board if the other is transmitting?! This will truly be a problem even if you had separate antennas spaced very close together as well. I may be wrong. Maybe there is special circuitry that detects excessive rf power and shunts it to ground to protect the circuitry. However if that happened you wouldnt receive the signal. Granted you are dealing with low RF power but hooking directly with same antenna without RF frequency isolation (which is not possible here) would be bad for the sensitive receiver section.


R2D2, I sure would love to have your take on this subject. If anyone knows for sure a solution please chime in.


I would not share the antenna, not at all.

Be careful how large of a wire you use. Or at least how long, because you can damage the transmitter. Seems like your current setup "works", but I'd just be careful:)


Thanks DJ, What about just putting an antenna on the main board and leave the other one alone? Any problem withthat?


The longer the antenna, the more work the transmitter has to do. The more work the transmitter does, the hotter it gets. The hotter it gets, the shorter life it has.:)

Up to you:D

I get a strong signal throughout my entire house. I can't go from second level to basement, but I can go basement to first level and second level to first level. I don't have any range issues.

A few things you can do instead of modifying the antenna. You can extend the cable on the bluetooh module, and put them higher up on your robot. Away from metal and away from each other (if there are two).

You can do the same with your controlling computer. Ensure the bluetooth dongle (if it's a PC) is not surrounded by wires and cables


Once more a big Thanks DJ, I only get about 30 ft. and if I go a round a corner forget it. It is really lilmited. I have the two EZ-B's as far apart as I can get them. Oh well, it is still most amazing and unbleiveabel fantastic. Wish I had your distance. By the way, the joy stick only is" line of site". Major bummer. I don't wish to sound negative. This is more fun that I have had in many years. Thanks so much. Buster lovers you! Regards form the bookmaker.


Ha I love buster! Have you considered XBee or Synapse? I know that Skater on here uses it. I think he has a break-out for it? I don't recall. Maybe he'll chime in.

Do a search for Xbee and see what you find


Yep, long range control of the EZ-B can definitle be done with 802.15.4 RF network modules such as XBees, but more so Synapse modules. If you check out the optimus prime bot in the project showcase area on the forums you can get a bit of info there but I do plan on making a longer more detailed post soon on long range serial transmission one of these days, along with my finding with the SOMO-14D module but haven't found the time yet.

While you can definitely achieve a longer than bluetooth range with Xbees, (which I have a bit of experience with) I would definitely recommend Synapse modules as they give a longer range and a much easier and cleaner configuration process and user interface.

On the hardware side of things for both types of module you will need to supply them with the 3.3V on the EZ-Bv3, Ground, RX, and TX. To do this you will need a breakout board of some kind, we have both at Solarbotics if you are interested. Also note that you will need a level shifting circuit on the RX line of the network module as it isn't 5V compatible, the easiest thing to do is add one resistor in series and one to ground in a voltage divider configuration in order to satisfy the needed 3.3V level. See the diagram for the Arduino Xbee shield if you like a visual aid.

I should be able to offer more info when more of my time frees up.


when you guys list g and kg can you please also list the weight in lb. for us that dont use that system? the same thing with meters, we use feet and inches. if we could see both inches/centimeters it would help us understand what you are saying better so we dont have to find a conversion program online just to understand. if its not too much trouble:) thanks TJ


hola r2d2 me gusta tu trabajo donde sacastes las placas de la robotica en pagina para pedirlo respondeme cuando puedas un saludo


@R2D2 - I just read this post again and I am still so impressed with your work. It does seem like you have a lot more options when you build the bot yourself. And I love your use of everyday (and inexpensive) items to make this bot. I have been truly inspired by him and you. Thank you for your posts!



Bret Thanks for your kind words, I'm glad I inspired someone with their robots, to a long time since we wrote in this post and that surprised me, my poor robot is hospitalized for an injury to its continuous rotation servos the wheels, waiting for new servos .. Greetings to Spanish friend, is a surprise to find a companion robots less than 1000km, I recommend the use of google translator that I use to write in the forum and everyone will understand you better. And happy new year to all!:)


R2D2 Wow nice construir, buena suerte con eso

feliz año nuevo también


Thank kudo48pa robotmaker and, while I think of building an improved version of the robot, something like a 2.0, improving its faults and qualities, also a body harder and more accessible to its interior, riding stronger servos continuous rotation as s8166m, more autonomy using 2 lipo batteries and a dual charger 10000mAh built. Perhaps in time ...


sick build R2D2. I hope to end up there with my build thanks for the inspiration.:D


hola r2d2 gracias por el saludo queria preguntar de donde sacastes las piezas servos ,placas


@R2d2. Wow you really turned some household trinkets into a work of art! Simple yet effective. Congrats I hope to see more;)


why are you not making any progress any more i like your work alot! good robot maybe we can call it "trashy bot";)


Thank you all, now little Timpo and economy to build robots but better times will come in the future..;)


Hola frankpalais! la placa de control es ez-b porsupuesto, los servos son chinos:mg995, los sensores de ultrasonido son los que aparecen en el tutorial, los puedes comprar aqui en ez robot, tambien en ebay, y la papelera te lo puedes imaginar(todo a 100), un saludo!


Some time ago I had to have posted this video, but the quality is not good, so I'll leave it because even as a kind of an end of the project ...


Dude, that is one of the cutest little dudes EVER!


Wow I love this robot, congratulations :)


Nice! I love how his "eyes" work.

Back on page 2 of this thread you show a diagram for your collision sensors. You have two momentary switches on each side wired in parallel with each other (one parallel per side). You show each side attached straight to a digital port on the EZ-B. I've been wondering if this was possible without causing damage to the EZ-B. I've been using the ADC ports for this purpose. I ran 5v from the ADC port to one side of the switch and the ADC sensor wire to the other side. Then had ARC look for the change of voltage when the switch was closed. Could you explain where you hooked your wires to the EZ-B digital port and how ARC knows when the switch is closed. How does the EZ-B board keep from shorting out when the switch is closed? I'm sure I'm missing something here.

Thanks in advance for the lesson, Dave Schulpius


Very cool robot, R2D2! I agree with all that he has a very interesting personality! I might suggest adding a varible speed for turning its head...just my thoughts :)


@ dschulpius hello! Long ago I did that and I did not remember, so I looked at the wiring of the buttons to ez-b and is connected between GND and digital signal port, then ARC is configured to read the digital port (two digital ports here, one for each side of the robot) @ irobot58 speed servo is a current feature, look at the date I started the project, at that time say that robots were a bit nervous.



OK, thanks. I need to give that a try. Do you have a script running that watches that digital port? I guess I don't understand how ARC knows to react when the button closes that attached to a digital port. In my project I'm using ADC ports for this and I state a variable in a script. When the voltage changes on that ADC port and reaches the variable stated the script will react the way I want it to. Could you share your script or project so I can see how your doing it?


The script is located on the first page of the project, under the pictures of the switch connections, I will look for the file and try and upload it to the cloud, although, it is written in the first versions of ARC. This script acts on the wheel servos that are continuously rotating, and colliding robot changes its course after a small reverse.


Ok the file is already in the cloud, but I notice that you have to remove the lines that include the command script sound_random I believe that this function was removed from ARC, dschulpius greetings!


Thanks for going through the trouble. Much appreciated! This will make for fun reading and will really help.

Thanks again! Dave


Although the video quality is horrible, I could not help post, I did it with an old phone and I found it by accident. I remember I spent all afternoon writing and tweaking a script to get the robot agarrase an object, leave him on a plate located in a particular place on the floor and return to his starting position, speaker beep tones in a robotic language. An adventure that brings back good memories, is therefore added. :)