Data Sheet

USB Configuration
Advanced Digital Motor Controller User Manual 153
The data at the output of the controller is +/-10V. At the other end of the resistor, the
voltage is clamped to around 0-3.3V by the protection diodes that are included in the Ar-
duino MCU. However, to avoid any stress it is highly recommended to insert the 2 diodes
shown on the diagram.
To operate, the RS232 output must be set to inverted. This must be done from the Con-
sole of the Roborun Utility while connected via USB. This will only work on newer control-
ler models fitted with firmware version 1.6a or more recent.
From the Console, send the following commands:
^RSBR nn
where nn =
5: 115200 + Inverted RS232
6: 57600 + Inverted RS232
7: 38400 + Inverted RS232
8: 19200 + Inverted RS232
9: 9600 + Inverted RS232
Make sure that the controller respond to this command with a +. Check that the value has
been accepted by sending ~RSBR. If a - is replied or if the value is different than the one
entered, then the hardware and/or firmware does not support serial inverted and cannot
be used with this circuit.
Send %EESAV from the console to store the new configuration to flash.
USB Configuration
USB is available on all Roboteq controller models and provides a fast and reliable commu-
nication method between the controller and the PC. After plugging the USB cable to the
controller and the PC, the PC will detect the new hardware, and install the driver. Upon
successful installation, the controller will be ready to use.
The controller will appear like another Serial device to the PC. This method was selected
because of its simplicity, particularly when writing custom software: opening a COM port
and exchanging serial data is a well documented technique in any programming language.
Note that Windows will assign a COM port number that is more or less random. The Rob-
orun PC utility automatically scans all open COM ports and will detect the controller on its
own. When writing your own software, you will need to account for this uncertainty in the
COM port assignment.
Important Warning
Beware that because of its sophistication, the USB protocol is less likely to recover
than RS232 should an electrical disturbance occur. We recommend using USB for
configuration and monitoring, and use RS232 for field deployment. Deploy USB
based system only after performing extensive testing and verifying that it operates
reliably in your particular environment.