Maestro commands supported via TTL interface

Hi All,

I have three(3) questions concerning the TTL interface in the Maestro Micro and Mini controllers:

  1. Are all Pololu AAh commands supported on the TTL interface?
  2. All channel configuration commands sent via the USB are supported via the TTL interface?
  3. Is there a comprehensive command syntax chart in one or two pages showing all the distinct command packets for the Maestro, currently some are outlined in the document but not all and would be nice to have a concise summary as a quick reference guide.

Thanks

Mark

Hello,

  1. All of the commands listed in the User’s Guide are supported on the TTL and virtual COM port interfaces.

  2. Channel configuration is NOT supported on the TTL or virtual COM port interfaces. The idea is to prevent software bugs from reconfiguring your Maestro in an irrecoverable or confusing way.

  3. The sections Serial Servo Commands and Serial Script Commands contain all of the commands. What do you think is missing?

-Paul

Hi Paul,

Thanks for responding at such an early hour much appreciated. It is unfortunate that the channel configuration wrt toggling between and input to output type channel is not supported via TTL it would have allowed more flexibility for 3rd party apps. Perhaps you can take this request back to the design team to have a defaul reset register command so users can restore if they reconfigure poorly and we have best of all worlds.
The Commands I am speaking of and perhaps I didnt read the manual properly are the commands to read registers as in the case of signal sensors etc. They are losely defined in the coding but would be nice to have those commands inclusive of the servo in one tabular sheet for easier reference.

Thanks

Mark

Hi Paul,

Perhaps I am making the command set more complicated than it actually is. If I want to connect an analog sensor to a channel/servo port do I simply do a get sposition and the feedback is the sensor value? So there is no need to classify the channel as a sensor rather than a servo output?

Thanks

Mark

Hello,

The position of a input channel is its measured value. It needs to be set as an input, or else it will setting the output voltage instead of measuring it.

Out of curiosity, why do you want to switch from input to output on the fly? Are you trying to use some kind of advanced sensor that requires switching? That is a reasonable feature request, but it would require a lot of things to change in the code and in the user interface, so I do not think that we are going to do it any time soon.

-Paul

Hi Paul,

Thanks for confirming my suspicion. The rational for the request is we are developing a HuD which permits the user to select which Channel they intend to use as a Servo, PWM or Sensor. If we have to comply with the current rules it means we have to preconfigure the Maestro units before we package them with the Kit. This is not a horrible workaround but it adds an additional step in the packaging and distribution workflow. BTW we currently use the 8 port Pololu to use the Servo port as a PWM on the fly, does the Maestro permit same at least for the Servo/PWM from an Output perspective?

Last question for now :slight_smile: Umm The default Device ID for all Maestro’s is 0Ch? Can we change this through the Configuration tool? We have a few Maestro (Micro/Mini) units coming to play with soon so this is some proactive investigation so we can finish the interface ASAP.

Thanks

Mark

Hi Paul,

The Rate frequency setting for servos, what is the standard to be comparable to the default settings of the 8 port Pololo Controller. We want our interface to behave seamlessly in this regard.

Thanks

Mark

Hello,

What is a “HuD”? If you are talking about some kind of PC software, you should consider connecting the Maestro to the PC with its USB port and using the native USB interface, which does allow configuration. (That is how the Control Center works.) You can get example code in our USB SDK.

I am a confused by your question about PWM, since our 8-servo controller does not have a PWM output or input option. The Maestro has a single PWM output, you do not get to choose which channel it is on, and it must be configured as an output. This is all specified very clearly here, so please take a look at that and let me know if you have any more specific questions.

As for your other questions, yes, the device number is 12, and it is configurable. The standard rate for servos is 50Hz, and that is what is used on the 8-servo controller as well. Do not change that unless you really know what you are doing!

-Paul

Hi Paul,

Excellent on all your responses. We propose to use the TTL to issue pololo commands primarily as we plan to use wireless via XBee rs232 cards. The reason for this approach is it permits easier plugnplay scenario with existing boards etc.
Guilty as charged only having read 65% of what we thought was pertinant of the Maestro manual but thank you for your patience and concise responses.
HuD - Heads up display or simply put a GUI not unlike your configuration console but with a visually pleasing interface like a cockpit.
Our goal is not to make autonimous Kits but PC driven kits. Time will tell if this is two steps backwards or not :slight_smile:

Cheers

Mark