hi there all,
I want to make a prototype Johnny Five head for my team project ( input-inc.com )
I`m looking into making function for the eyes and eyelids.
The eyelids on J5 require a total of 10 servos, so I`m getting a Maestro 12 for that, and each eye system will use 4 servos, and require a relay switch to reverse a voltage supply to some bi-colour LED`s. I have some Maestro 6`s already for the eyes.
Can I link all the maestros to one system ? ( eventually many systems will be required in J5 ).
I will need the pair of M-6 to run simulteanously, with some `mirrored servo` function, and the M-12 to run `separatly`, but run all run from a single micro controller / PC .
I cannot use the M-18 or M-24 for this aplication, as due to cabling and servo position, each eye will acctually contain the M6 servo conrollers, and the M12 will ne behind the
nose of J5.
also, as mentioned above, I require an electronic switch in each eye to give three states : Off, +/-, -/+, can the Maestro do that ? as I will have output lines spare on each M6.
To run three Maestros from a single PC, you should connect them all with independent USB cables if possible. To connect to a single microcontroller over a single serial port, you can use the chaining feature described in detail here - and three controllers in a chain should be no problem at all.
I am not sure I understand your plan with the relays, but it sounds like overkill. If the LEDs need 10mA or less, you should be able to power them directly from the Maestro channels. Each channel is protected by a 220-ohm resistor, so you will need to do something more advanced if you want more current than that. But even then, a relay probably would not make sense, since most relays take more than 10mA anyway!
For the testting purposes, I will connect all three Meastros to a PC seperatly via a USB hub ( that ok ? )
Though I do want to run them all together, does the controller program sync with other instances of itself?, or can one program control more than one Meastro?
As for connecting three on a dasiy-chain to a microcontroller, I assume its all good to have more than one type of controller on the line ?( 2off maestro 6 & 1 maestro 12 )
As for the LED`s, heres the explanation of their use first. - If you have seen the Short Circuit movies, you will understand better; Johnny 5 has three main states of illuminated eye: Bright red, Bright white and Off.
I have found this led : rapidonline.com/productinfo … 2#techspec
I have made an array of 24 LED per eye, in 3parallelx8series array. The array draws about 250mA @ 12v
I need control to switch between these three states. I would like to link these into the Maestros, but if thats not directly possible, could it be done via a microcontroller?
Talking of microcontrollers, for the application of controlling Johnny 5 eye movement and eyelids ( basically - his
expression), which controller would you recommend?
A USB hub should be perfectly fine.
The Maestro Control Center only controls a single Maestro at a time. To control multiple Maestros, you can either run multiple control centers or write your own software to talk to all of your Maestros simultaneously.
You can definitely have different Maestros on a single serial chain. Please read over that daisy chaining manual for complete information on chaining.
Now, the LEDs - wow, those are going to be bright! Have you tried it to make sure you are not going to be blinding people?
Anyway, to drive more than 10mA with the Maestro, you will probably need some transistors or MOSFETs. If you can change your setup so that the LEDs are on two separate channels, you can use a single N-channel MOSFET between the LED and ground. Google sometihng like “mosfet to switch LEDs” for examples. However, if you really need to do it with these bidirectional LEDs, the easiest thing by far is going to be to buy one of our motor drivers: the TB6612FNG Dual Motor Driver Carrier would be ideal.
thanks for that info, i have been trying to get 2 maestro 18’s for my humanoid robot to work correctly as i was under the impression that you could chain them together, hook 1 usb up, and be able to control both boards through the software. guess not!
so here is my question: my project requires accurate timing between both boards for walking squences, what is the best method for programming? should i run two control centers to program the movements? i have one maestro being used for one half of the body (left arm, left leg) and one maestro for the other half. in order to fine tune a walking script, i need to be able to start the scripts on both boards at exactly the same time, is this possible running two control centers for each board? writing my own software is not an option right now. would this mean that i would basicly end up with one half of the walking script on one board and the other half on the second or could the complete script be run from one board and send the proper signals to the second when chained (less chance of timing issues?)?
my project uses 18 servos right now, but after head, hands, and other items are added, i will need the extra channels, would it have been better to use say 1 24ch maestro? im thinking so.
thanks for your input, any ideas are always welcome and i will post pics of the bot soon, its pretty amazing stuff for homemade!
We would love to see pictures of your robot in whatever state it is in!
Anyway, have you actually decided whether or not you want to have a PC on the robot? If so, it makes a lot of sense to have the PC doing the control. If not, you should be looking into controlling both Maestros from a single microcontroller or having one control the other.
You say that writing your own software is not an option, but there are different levels of programming, and working with Maestro scripts is one of them. Are you saying that you do not know how to do anything beyond that?