Hello,
I bought a Micro Maestro 6-Channel USB Servo Controller and now i want to figure out, how to connect the Micro Maestro 6-Channel USB Servo Controller to the serial port of my computer.
Because I have LabView I need the serial connection.
Can I connect the Servo Controller directly to a serial port at a computer or do I need a RS232 to TTL converter ?
I hope you can help me.
Thanks and greetings from Germany
I have been using Labview to control maestro servo controllers. If you follow the maestro driver installation in the Getting started section of the Users Guide, it will install “virtual com ports” which you can examine in the Windows device manager. This will show the actual virtual com port numbers assigned to the maestro command and TTL ports. To get started I suggest using the com port that is assigned to the maestro command port. (Use this com port number in your Labview code when you initialise the serial port). Labview will communicate with this virtual com port, the maestro driver you have installed will do everything needed to take the data from the virtual com port and actually use the USB port and on into the meastro servo controller board.
Depending on your Labview installation, you will probably need the SERIAL VISA device driver, a common add on from National Instruments.
If you want an example virtual instrument, vi, there is a link on this Pololu forum to a vi which got me started so it might help you.
sorry dont know how to put the hotlink in here but if you search the Pololu servo controllers forum for
"SSC03A control with Labview"
you should find it. Good luck
Hello, sps.
I just wanted to add that you should be sure to configure your Maestro to be in “USB Dual Port” mode. Also, this Labview Vi for the Maestro, which was made by another customer, might be useful to you:
–David
Hi,
thanks for your answers.
How to communicate with the controller do i know. I found a lot of helpfull threads in this Forum.
My question is how to connect mechanically ?
Can i directly connect it to the COM port or is a TTL converter needed ? Because i dont want to destroy the controller.
Can i connect it with this ?
If your computer has USB I recommend just using that. As gordonsmith said, the Maestro creates a virtual COM port that you can use just like you would use any other serial port (except it’s a little easier because you don’t have to choose any particular baud rate when connecting).
–David
If you insist on using your illustrated connector between a computer RS232 Serial COM port and the Maestro Servo Controller board, in theory I see no reason why not, however, I just did a WIKI search on RS232 specification and the valid voltage levels are plus or minus 3 to 15 volts, although the actual voltage levels used depend on the implementation of the port on the particular computer (available PSU voltage levels, UART chip type that is used etc). So, you must ensure that the voltage levels arriving at the Maestro are within its specification (TTL levels 0 to 5v) and this will probably require some voltage level shifting (and similar level shifting from the Maestro to the computer). I believe It is possible to operate RS232 using just 3 wires (TxD, RxD and earth) so the level shifting circuit would be needed on TxD and the opposite sense on RxD.
Also, of course, make sure you have earth pin of the 9-way Dtype connector connected to earth on the Meastro, also TxD connected to RX on Maestro (VIA Voltage level shifting), and RxD connected to TX on Meastro (VIA Voltage level shifting).
Maybe you do not need communication back from the Maestro in which case you could just use TxD (Via voltage level shifting) and earth.
Labview would control the serial COM port in exactly the same way as it would control a Virtual COM port.
Personally, I think you should really try to use the USB/virtual COM port method.
Good Luck. By the way, I really like these Maestro boards, I think they are quite versatile.
Addition to my previous posting:
If your computer has USB, I don’t just recommend you to use it, I INSIST. It will be so much easier, plus you get the massive benefit of being able to use the (excellant) Meastro Control Centre for testing.
Greetings from England.
Hey Guys,
thanks for your answers.
I’ll try the USB method with the virtuall COM Port. But i have a distance of 15 meter between PC and Pololu.
I already use a USB-Repeater (up to 60m via RJ-45) but its in use by a Webcam, maybee Webcam and Pololu will work with the Repeater.
If not i have ordered a RS232 to TTL Converter its very similar like the Pololu 23201a
Datasheet RS232 to TTL Converter
I’ll keep you posted
by SPS
