Hi. Im a brand new member, I recently decided i want to try and build some sort of robot.
Basicly, i just want something i can make walk around, and self-balance itself, as well as grab stuff and carry it around. (light stuff)
I work as an electrician, and have a good mechanical/electrical/fabrication base, but know almost nothing about little robots.
Were should i start, and how much money should i expect to invest in all the gadgets ide need? Im planning on building everything i can possibly build, excluding motors/servos etc.
I have a few 7.2v batteryies, around 3000mah, RC car servo’s, and controls. are these worth holding onto?
Also, how difficult is it to go from simple relay controls, to make it interact and get commands from a pc?
Im sorry this post is full of ignorance, but im still young, and got lots to learn! Any advise, about anything robotic related, would be greatly appreciated!
Where should i start, and how hard is this whole self balance thing?
-Thanks, and heres to hoping this forum likes noobs! :mrgreen:
done a lot more reading and now i understand a lot more about micro proccessors. just like PLC programs.
what do i all need to start my endevor? I want the ability to control a motor, and 15 or so solonoids/servos, and to hook it all up to my PC and tune in photosensors and gyro sensors, and all kinds of neat stuff.
Im looking to keep it pretty cheap, and easy, but have the ability to go really in-depth when my skills are better.
also, i could use the microprocessor to control a RC Car ESC, and use that to control the speed? or do i have to buy like a special controller or…
Hi,
Right into it you’ll have to get am MCU and either a motor controller or a SSC32 servo controller.
There is tons of info on this site about the Atom Bot Board and SSC32 servo controller which can almost control anything that you want ( servo’s, relays, etc. )
and there is lots of info about sensors.
It can be a bit slow around here on the weekends, but people do like to help out. The main people should be back tomorrow. Please don’t worry about being a noob, we all started out that way. Keep on asking questions.
From your description it is hard for me to know which direction to advise you, but I will describe a few different ways to go.
If you are mainly interested in controlling stuff such as a servos and a motor, with minimal input from other devices. You could start off with something the SSC-32( lynxmotion.com/Product.aspx? … egoryID=10. But please note, what motor controller will depend on what type of motors and how much current they draw. You would then connect it up to your PC and have a program on your PC send commands to control the servos and the like. These commands are simple Ascii text strings. However this limits you to only 4 input pins which can be either analog or digital.
Or you could start off with a microcontroller such as the Basic Atom Pro BAP(lynxmotion.com/Category.aspx?CategoryID=66). You can connect your servos to the BB2 and like the SSC-32 you will probably need some form of motor controller for other types of motors. Here you have the flexibility to add lots of other devices. However this will require a program to be downloaded to the microcontroller to do anything. You can also have a program on the PC communicate with your microcontroller, but again you will have code on both sides to do this. Now if your desire is to start off with one of the kits Lynxmotion sells, there are programs available as a great starting point. Personally I prefer this approach. But you can also go with a hybrid approach where you have both a microcontroller and the SSC-32.
You probably need to more define your goals before you can estimate how much it is going to cost. For example:
You say have it walk around. This implies legs. How many? How big. What types of obstacles do you wish for it to get over. For example if you need it go up stairs, this adds lots! Also you say you wish for it to pick up things. When you say you wish for it to grab things, how big? How much of a reach does it need? How much will will it all weigh… These things really have a large impact on cost. If for example you wish to build something that is small enough to use cheap servos like: HS-485HB you can get these for approximately $18 each. However if you need real heavy duty servos like HSR-5990 these are maybe $125 each. can you use your RC car parts like servos/battery, etc. Maybe, depends on how it fits in with your other stuff. Also some servos really do not like 7.2V so depends on what you end up choosing.
There are several ways to replace relays, depending again on what voltages and current you wish to handle. For example: lynxmotion.com/Product.aspx? … goryID=106. They also have a larger version for higher currents. However I don’t think either of these for example could work to replace a 110v relay…
Again welcome and I am sorry that my ramblings can at times be a bit hard to follow and I know I did not answer everything.
I suppose i could be a little more specific on my goals
Walk around on 3 legs/arms, with 2 legs for movement up front, and a 3rd in the rear for balance. able to grasp (just 2 jaw) something, and move it around like a generic robotic arm, while holding its balance on the remaining 2 legs/arms. as far as weight, its going to be almost all plastic so it will be light, and i dont plan on picking up anything heavyier than a pound.
As far as writing the code goes, i read alot of how to’s and whatnot, but it kinda seems like i have to have it in front of me, to understand. Is this something i could teach myself, if i ordered a bot board starter pack, and motor control etc.? Looking at the boards, and how they clip together, and how to wire up the motor controls (saw schematics) all that looks easy… What im mainly concerned about, ide guess, is the actual programming.
Is the programming simple enough that i could catch on myself, with a few pointers? or is it something you generally have to be intently shown by someone?
Also i should note i have a 3s 5000mah lipo battery, and was wondering if anyone here is using pnuematics as a way to build stronger robots?
It really depends on your background. If you have any experience in programming at all you’ll find that the basic ideas carry over to other languages and can be used when programming your robot. This can help get you started but there’s definitely still a learning curve to understanding how to use microcontrollers. I used the Parallax BOE Bot (parallax.com/Store/Robots/RollingRobots/tabid/128/CategoryID/3/List/0/SortField/0/Level/a/ProductID/296/Default.aspx) to get started in programming. I found this kit to be an excellent learning tool because it comes with a detailed book that guides you through the basics step by step. You don’t need any previous experience to get started and once you finish the book you’ll be able to build a fairly complex robot on your own.
Once you’re comfortable with the BASIC programming language and how to use microcontrollers, you can graduate up to the BASIC Atom Pro line of microcontrollers and more capable development boards such as those offered by Lynxmotion and start building some “real” robots. Of course the BASIC Atom microcontrollers and Lynxmotion boards can also be used for getting started. I only suggest the Parallax BOE Bot because their books will guide you through use of this robot and components specifically.
Pneumatics can definitely provide a lot of power in a small package but the main limitation for use on a robot is the air reservoir capacity. Unless you plan to build a very large robot, you won’t be able to include a compressor pump to supply the necessary air pressure. Even if you do, you’ll likely need a large amount of batteries to run this pump which can add enough weight to negate the added power available from pneumatics. Instead you’ll need to pressurize the reservoir before use and your run time will be limited to how long it takes the pressure to run out. This might be feasible if you use pneumatics for only one function where you really need power such as the grabber hand. Pneumatics also offers the benefit of no additional power draw while applied which is perfect for grabbing a heavy object and holding it for an extended duration.
the only relevent experience i have is PLC programming, but its the same basic idea. I/O based, that you must write a code and install into it, and connect sensors, and make it respond to the sensor how you want through code. Hopeing its similar…?
Anyways, ive decided im deffinitly best buying a small ‘DIY’ robot, which would have two purposes:
To help me learn to program,
Something i can take the parts off of (the microcontroller and other gadgets) to build my own much more complex robot, without having to buy a new ‘brain’, only stuff to add to it.
eventually ide like a robot that could interact based on what it sees in ‘realtime’, and hears (key words, or phrases) and responds to them. How realistic is that?
Based on my eventual goals, and realize my budgets below $500 total (to start), what would be the best kit to choose as my first kit?
Having experience with PLCs should give you a decent foundational understanding of the ideas and components used in robotics. A PLC is essentially a microcontroller but in a complete hardened package for use specifically in industrial applications. They’re usually programmed in different languages but operate in very similar ways using inputs, outputs, and the logic necessary to interpret inputs and control outputs. Another difference is how you work with the hardware itself. PLCs usually have standard connections so all you have to do is plug in a sensor or controller. With hobby robotics you’ll often be working with less “industrial” connections and will need to keep a closer eye on polarity and wiring to avoid letting the “magic smoke” out of your components.
Vision is still a very complex capability for hobby robotics. There is a large amount of sensors available that can detect brightness, color, shapes, and motion but it’s usually very difficult to effectively track specific objects outside of a controlled space. It’s not impossible to implement a vision-based sensor system but you’ll need to find ways to account for varying ambient light levels, multiple items in your environment that are similar to the color you want to track, shadows, and several other issues. If you search around the forum and online you’ll find most hobby robotics projects with vision systems are usually only capable of identifying brightly colored objects in close proximity and in a controlled indoor environment. Again, vision systems are not impossible to implement but just be warned that there are limitations and usually more significant learning hurdles to overcome.
I’d still recommend the Parallax BOE-Bot as the ideal starter robot. It’s relatively inexpensive at $160 and the included book is a terrific guide for anyone getting started in robotics. Parallax also offers a huge assortment of add-ons and components so you can keep using the BOE-Bot even after you finish the book. The BASIC programming language used with the BOE Bot can also be used with the BASIC Atom line of microcontrollers which will give you even more capabilities and performance when you’re ready to move on to more advanced projects. If you’d like to learn more, there’s a lengthy article in the current issue of ROBOT magazine all about the BOE Bot. You’ll also find articles about the awesome Lynxmotion Mech Warfare BRAT and many other robots.
Im deffinitly going to take your advise, and order the little boe bot
The only questions i have left are:
Is there anything you would reccommend ordering at the same time? such as an upgrades, or sensors?
how strict is this forum on discussing other companys products?
and last but not least, when it comes to tech problems, where would i have my best ‘audience’ to hear my questions? i dont wanna be the guy with a Ford, in a Dodge only repair shop!
Most Parallax stuff is ok cause frankly our stuff is really much more advanced. The BoeBot and Basic Stamp are easy to use. But after a while you will find the small program space and limited variable space too limiting to do anything complex.
The BOE-Bot kit comes with everything you need to complete the examples in the book. You won’t need anything else until you’re ready to move on to more challenging projects or want to try out some more exciting sensors such as ultrasonics.
I recommend the Parallax BOE Bot for beginners but Lynxmotion is the place to find components and kits once you’re comfortable with the basics and ready to start building “real” robots. You can do quite a bit with the BOE Bot but it won’t take long before you reach the limits of the hardware and get the urge to do more. When that time comes you need look no further than Lynxmotion.
The Lynxmotion and Parallax forums are great sources of support but you can also utilize local robotics clubs such as ChiBots (chibots.org/) and CIRC (circ.mtco.com/). Both clubs have Yahoo Mailing Groups which you can subscribe to and submit your questions for all club members to see. These mailing groups can be a powerful tool for getting suggestions on local suppliers and learning about upcoming robotics events in the area.
By the way you guys are talking, now, i think i might be better off getting something with a bot 2 board in it. I have an addictive habit when it comes to electronics. How much more difficult is it to program, and what are the basic differences ?
Just bigger space available, or is there way more sensors available? Im trying to learn as much as i can before i order my bot, i want to make the right choice. After you said its kinda like PLC’s i feel very confident :mrgreen:
I would rather shell out the extra $200 for a far superior board now, than have to buy it in addition too, and learn a whole new program, later on. how much further advanced is the bot board, and whats the diff?
someone should sticky a pro’s and con’s list somewhere i find it very hard to find actual usefull knowledge about what im trying to accomplish, and what i need to do it. this forum has been my only advisor so far.
The Bot Board II is what we refer to as a development board or carrier board and essentially serves the role of “motherboard” for your electronics system. The microcontroller is what you’ll actually be programming while the Bot Board provides all of the necessary connections between the microcontroller and your servos, motor controllers, sensors, etc… You have the option to install any 24 or 28 pin BS2 like microcontroller such as the BASIC Atom, BASIC Atom Pro, or BS2 microcontroller. The differences in performance and capabilities will depend upon which microcontroller you use.
The Parallax BOE Bot uses the BASIC Stamp 2 microcontroller while most Lynxmotion robots are designed for use with BASIC Atom Pro microcontrollers. Both controllers are programmed using variations of the same language but the Atom and Atom Pro have a few additional features not offered by the BASIC Stamp 2. The BASIC Atom controllers also offer faster processing power and more memory for storing variables and larger programs. There are some other slight variations with the syntax but usually the same program can be used with either microcontroller after just a few tweaks. For more information about BASIC Atom microcontrollers, visit the following links:
For the most part each microcontroller can use the same sensors and other hardware. All sensors work by providing either an analog reading (0-5V output) or a digital output (High 5V or Low 0V) and these inputs can be interpreted by either microcontroller. What you will find however is that certain sensors require faster sampling rates (more measurements per second) in order to operate correctly and this will require a faster microcontroller.
Thanks for the info, and i found the one link extremely helpful!
I also happen to have 2 brushless speed controllers and motors, traxxas.com/products/electri … etails.htm heres a link the the ESC. Its off a traxxas rustler, and it plugs into the receiver, just like a normal servo does. I would assume, these setups would be ideal for a higher powered rover, correct? same as ‘your’ speed controllers, but in a nifty package, right
If i were to buy the boe bot, i could program them to be controlled by the bot, without any extra components, assuming both devices work off the same signal streangth?
You could use these components to build a high-speed robot but keep in mind that this robot will be functioning autonomously. If something goes wrong you wouldn’t want it to be capable of getting away from you that quickly or possibly doing damage to its surroundings. Builders tend to use slower gear motors in their robots for slower top speeds but higher torque.
A hobby ESC (electronic speed controller) operates using the same PWM (pulse-width-modulation) signals that a servo would use which happens to be what the BOE Bot uses to power its wheels. A PWM signal is merely a 5V input voltage that goes from high (5V) to low (0V) repeatedly several times a second. The duration of time the signal remains high is refereed to as the pulse width. The following link describes how a servo works and how PWM signals function:
An RC receiver in a remote control plane or car outputs PWM signals based upon the inputs sent by the transmitter. This PWM signal normally ranges from around 0.75ms to 2.25ms with the neutral position (transmitter controls centered) around 1.5ms. A 1.5ms PWM signal sent to an ESC or servo would command the motor or servo to hold its neutral position and stop. Anything above 1.5ms would command the servo or motor to spin one direction and anything under 1.5ms would command the opposite direction.
Each servo and ESC will reach it’s maximum directional speed at different PWM signals so you’ll need to experiment to see where this lies. For example many standard size servos will operate from 1300uS - 1500uS - 1700uS while many digital standard servos operate from 1100uS - 1500uS - 1900uS. When using servos you need to be especially careful not to command a servo too far or you might damage the motor and gears. ESCs are more forgiving about this but you’ll have to do some experimenting to find the PWM range as this data tends to be difficult to find for ESCs.
An important detail about PWM signals is that it is imperative the signal be supplied to the ESC or servo at least every 20ms. This can be done using a BASIC Stamp 2 but you’ll need to make sure the microcontroller isn’t bogged down processing other inputs. The BASIC Atom Pro on the other hand includes a special function called HSERVO which will automatically provide the ESC or servo with the specified PWM signal every 20ms.
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how much further advanced is the bot board, and whats the diff?
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