Hi, I have micro maestro connected via usb to computer with windows 7. I am using the driver to move two servos, powered by external supply. When I unplug dc supply, after some time plug it again, everything works fine. But when I do it again, control maestro is turnig off, leds are off, and when i start maestro control center i’ m getting error message “There was en error getting the firmware version from the device. Control transfer failed. Error code 0x1f” And the next one “…there was en error getting parameter PARAMETER_SERIAL_MODE from the device…” After reconnect usb cable everything is fine. Why I can’t unplug power even if i am not connected with maestro ?
Hello, sphinx.
I’m sorry you are having trouble with the Maestro.
Are you saying that you’re doing the same exact thing (“unplug dc supply, after some time plug it again”) two times and it always works the first time but always causes this problem the second time? Is it really so predicatable?
What do you mean by “control maestro is turnig off”?
How are you powering the Maestro itself? If you are going to have USB plugged in all the time, it is best to leave the VIN pin disconnected.
Another customer has reported that the Maestro’s servo power supply can have bad effects on the Maestro’s USB connection similar to what you are describing. After the problem happens, the simplest way to correct it is to unplug the USB cable and plug it back in, but the problem can also be corrected by disabling/re-enabling the driver of the Maestro’s composite USB device.
–David
Yes it’ s always the same, after first dc unplug it’s ok, after second time it looks like maestro have no power. I have VIN pin disconnected.
Disabling/re-enabling the driver of the Maestro’s composite USB device have no effect. Only way to fix the connection is to unplug the USB cable and plug it back in
In the Maestro Control Center, in the Serial Settings tab, could you please try checking “Never sleep (ignore USB suspend)” and see if that changes the behavior of the LEDs on Maestro? This should tell us whether power is being delivered to the USB port while the system is in this bad state.
–David
When I set never sleep, after first dc unplug, only orange led is blinking, and i can’t connect to maestro. Is it normal that after connect dc supply servos are moving (maestro control center is closed, on startup or error is off) ?
It is normal for the servos to briefly twitch when you start applying power to them. If the Maestro isn’t sending pulses to them (i.e. the Enabled checkbox in the status tab is not checked) then the servo will not be able to hold a position.
–David
It was my fault. I have connected 2 servos to DC supply with 500mA current. When I am connecting DC supply, two servos trying to move, sometimes the start-up current is two high for supply, thats why I’m losing connection with maestro. In my program I have time interval (100ms), so the servos never start at the same time and it’s ok. So the reason of problems is DC supply
I am glad that you solved your problem, and thank you for telling us what you did. --David