M3-FS_movement

The Plan

• We want to use the M3-FS, a piezo-electric that can finely move a lens back and forth while on the drone.
• We want the movement of this piezo to be based on the distance between our two drones
• First we must be able to move the M3_FS while is it connected to the drone.
  • To do so, we fill have a raspberry pi on the drone that will be able to communicate with the M3-FS. We in turn will be able to connect to the RPi over a shared network and move the M3-FS
  • From what I saw, the given software (from the company) to use the M3-FS isn't compatible with its OS. In addition, we need to be able to move the piezo based on an external variable (Drone distance) which the given software also cannot take in and use.
  • So we will mess with the RPi interface to communicate with the M3-FS via a serial port and make our own code.

Instructions

All of this should already be done for both the raspberry pis that we are using. However, if nothing is being recognized in the ttyUSB0 port, then these are the instructions to get there

1. Associate M3-USB interface to a virtual COM port To change the USB to UART’s vendor/product id to that of a VCP you must do the following…

   How to create virtual COM port

   1. Install the NST Pathway software onto a Windows PC as well as the SiLabs VCP driver for Windows.

   2. Run the NST USB Bridge Setup program to change it to appear as a Virtual COM Port (this utility is available from the Start menu once the Pathway software has been installed).

   3. Connect to the M3-FS, through the M3 USB Interface, using the Pathway software.

      • From the Pathway Setup Connection dialog, you must manually change the baud rate selection from 115200 (the default for a COM port) to 250000 (the preset baud rate in the M3 USB Interface).

      • Once connected (i.e. you close the Setup Connection dialog and click Connect on the main window), change the M3 USB Interface’s baud rate to 115200 by entering the following command into the Manual Command Entry text box (excluding quotes): “TR<54 1 03>” and click Send. You must do this because Linux may not accept a baud rate of 250000. After sending that command, wait at least 5 seconds before removing the M3 USB Interface from the PC. To test it, plug it back in and, this time, when selecting the COM port from the Setup Connection dialog, select the baud rate of 115200 and confirm that it communicates.

   • The following link takes you to the available VCP drivers: https://www.silabs.com/developers/usb-to-uart-bridge-vcp-drivers. For Windows, use the “CP210x Windows Drivers”. They have multiple choices for Linux and I don’t know which you should use. Raspberry pi debian OS often already comes with this driver installed. After restarting, the raspberry pi it should recognize the M3-FS (for me it was on /dev/ttyUSB0)

2. use either the python or C++ code to send messages through the M3-FS either manually or automatically based on PX4 data. some help will be given in each subdirectory