Houston Telnet Client connects to Houston Server (address 0x1) via TCP / IP protocol, from where commands are transmitted via ground UHF via radio channel to onboard UHF via AX.25 protocol. Commands are sent from the onboard UHF via the CAN bus to the Raspberry Pi, where the onboard Houston Server converts them from CAN to TCP / IP. Then the commands go through the socat utility, which transmits a stream of characters from TCP / IP to the bash terminal.

As a result of executing commands, files from the Raspberry Pi are transmitted via UHF and saved in the corresponding folder of the Houston Telnet Client.

Install the Houston Telnet Client program from the page Required Software

Start the Houston Server program, which the Houston Telnet Client uses to communicate with the UHF ground transceiver.

Connect the ground UHF transceiver to the computer via USB, open the Windows Device Manager and make sure that the new device appears in the COM and LPT ports section.

Run the Houston Telnet Client software, the TCP / IP connection status will be displayed in the status bar.

Buttons description:

• ls - display information about files and directories.
• The CR LF checkbox sets the end-of-line character (0x0A if unchecked and 0x0D 0x0A if checked).
• Receive File - starts the transfer of a file from the onboard folder to the ground folder. The text box on the right contains the name of the file from the current directory.
• The Ymodem checkbox switches to the Ymodem protocol (the Zmodem protocol is used by default)

• The Overwrite checkbox instructs the recipient to overwrite the local file with the same name.
• The Resume checkbox allows you to switch to resume mode if the previous file transfer was interrupted.
• Send File - starts the transfer of a file from the ground folder to the onboard folder.
• Cancel - Sends a terminate character to the sender and cancels the local receive procedure.
• Break - Sends a termination character to the sender (used when the sender is not available after the file has been transferred).
• End line - Flushes the shell input buffer and receives a shell prompt.
• List Photos (ls -l command) - Shows a list of photo files in the photo directory.
• Receive Photo - starts the transmission of a photo with the number indicated in the text field on the left from the onboard folder to the ground folder.
• Receive Thumb - starts the transmission of a preview of the photo with the number indicated in the text field on the left from the onboard folder to the ground folder.
• Remove - removes a photo and its thumbnail, with the specified number, from the onboard catalog of photos / thumbnails.
• Clear - clears the text area of the log.
• Shot! - take a photo (creates a photo file and a preview file).
• Settings - opens the settings window.

Houston Telnet Client settings window

The settings window allows you to configure the following parameters:

• Telnet port - Houston Server connection port, IP: port (60015 - for working with Raspberry Pi, 60002 - for working with onboard UHF).
• Zmodem - window size, receive timeout, transmit block size.
• Remote paths - remote (onboard) photo directories, photo file extensions, a script for creating a photo.
• The default script shot.sh needs 2 parameters: camera number and output file format. For example, for a photo from a Raspberry Pi onboard camera, the following Shot script parameter is used:

/home/pi/scripts/shot.sh 0 jpg

Local paths - local (ground) photo directories and directories for another file uploads.

Последовательность действий по загрузке фотографий с бортового Raspberry Pi на компьютер через УКВ.

Downloading photos from the onboard Raspberry Pi to a computer via VHF:

1. Make sure that the status Server: connected is displayed in the status bar of the main window. If not, check the Telnet port parameter in the Settings and connect to the Houston Server.

2. Press the End line button. A shell prompt should appear in the terminal's text box.

3. Press the List Photos button. A list of photo files should appear in the text box of the terminal. Suppose the filenames match the following pattern: # .jpg.

4. Enter the photo number in the text box to the right of the List Photos button. Then snap the Receive Thumbs button to upload thumbnails or Receive Photo to upload photos. When the download starts, the Houston Telnet Client window looks like this:

5. Wait for the file transfer to complete. The estimated download speed and progress bar are displayed in the status bar. At the end of the transfer, the Houston Telnet Client window looks like this (a message appears in the log (“File receive ends”):

6. Press the “End line” button. The shell prompt should appear in the terminal text field.

The downloaded files will be in the corresponding folders of the Houston application telnet Client, photos in the “photos” folder, and thumbnails in the “thumbs” folder.