--- id: usage title: Using the Meshtastic CLI sidebar_label: Usage slug: /software/python/cli/usage sidebar_position: 2 --- This section covers using the "meshtastic" command line executable, which displays packets sent over the network as JSON and lets you see serial debugging information from the Meshtastic devices. :::note The `meshtastic` command is not run within python but is a script run from your operating system shell prompt. When you type "meshtastic" and the prompt is unable to find the command in Windows, check that the python "scripts" directory [is in your path](https://datatofish.com/add-python-to-windows-path). ::: ## Getting a list of User Preferences You can get a list of user preferences by running '--get' with an invalid attribute such as 'all'. ```shell meshtastic --get all ``` ## Changing settings You can also use this tool to set any of the device parameters which are stored in persistent storage. For instance, here's how to set the device to keep the Bluetooth link alive for eight hours (any usage of the Bluetooth protocol from your phone will reset this timer) ```shell title="Expected Output" # You should see a result similar to this: mydir$ meshtastic --set power.wait_bluetooth_secs 28800 Connected to radio... Setting power.wait_bluetooth_secs to 28800 Writing modified preferences to device... ``` Or to set a node at a fixed position and never power up the GPS. ```shell meshtastic --setlat 25.2 --setlon -16.8 --setalt 120 ``` Or to configure an ESP32 based board to join a Wifi network as a station: ```shell meshtastic --set network.wifi_ssid mywifissid --set network.wifi_psk mywifipsw --set network.wifi_enabled 1 ``` :::note For a full list of preferences which can be set (and their documentation) can be found in the [protobufs](https://buf.build/meshtastic/protobufs/docs/main:meshtastic#meshtastic.User). ::: ### Changing channel settings The channel settings can also be changed, either by using a standard (shareable) meshtastic URL or you can set a particular channel parameter (for advanced users). :::warning Meshtastic encodes the radio channel and PSK in the channel's URL. All nodes must connect to the channel again by using the URL provided after a change in this section by performing the `--info` switch. ::: ```shell meshtastic --ch-set name mychan --ch-index 1 --info ``` You can even set the channel preshared key to a particular AES128 or AES256 sequence. ```shell meshtastic --ch-index 1 --ch-set psk 0x1a1a1a1a2b2b2b2b1a1a1a1a2b2b2b2b1a1a1a1a2b2b2b2b1a1a1a1a2b2b2b2b --info ``` Use `--ch-set psk none --ch-index 0` to turn off encryption. Use `--ch-set psk random --ch-index 0` to assign a new (high quality) random AES256 key to the primary channel (similar to what the Android app does when making new channels). Use `--ch-set psk default --ch-index 0` to restore the standard 'default' (minimally secure, because it is in the source code for anyone to read) AES128 key. All `ch-set` commands need to have the `ch-index` parameter specified: ```shell meshtastic --ch-index 1 --ch-set name mychan --info ``` ### Ham radio support Meshtastic is designed to be used without a radio operator license. If you do have a license you can set your operator ID and turn off encryption with: ```shell title="Expected Output" # You should see a result similar to this: mydir$ meshtastic --set-ham KI1345 Connected to radio Setting Ham ID to KI1345 and turning off encryption Writing modified channels to device ``` Toggling `set-ham` changes your device settings in the following ways. | Setting | `set-ham` Default | Normal Default | | :----------: | :---------------: | :------------------------------------------------------------------------: | | `IsLicensed` | `true` | See [User Config - IsLicensed](/docs/configuration/radio/user#is-licensed-ham) | | `LongName` | _Your CallSign_ | See [User Config - LongName](/docs/configuration/radio/user#long-name) | | `ShortName` | _Abrv CallSign_ | See [User Config - ShortName](/docs/configuration/radio/user#short-name) | | `PSK` | `""` | See [Channel Settings - PSK](#changing-the-preshared-key) | ## Changing the preshared key You can set the channel preshared key to a particular AES128 or AES256 sequence. ```shell meshtastic --ch-set psk 0x1a1a1a1a2b2b2b2b1a1a1a1a2b2b2b2b1a1a1a1a2b2b2b2b1a1a1a1a2b2b2b2b --info ``` Use "--ch-set psk none" to turn off encryption. Use "--ch-set psk random" will assign a new (high quality) random AES256 key to the primary channel (similar to what the Android app does when making new channels). Use "--ch-set psk default" to restore the standard 'default' (minimally secure, because it is in the source code for anyone to read) AES128 key. All "ch-set" commands will default to the primary channel at index 0, but can be applied to other channels with the "ch-index" parameter. ## FAQ/common problems This is a collection of common questions and answers from our friendly forum. ### Permission denied: ‘/dev/ttyUSB0’ As previously discussed on the [forum](https://meshtastic.discourse.group/t/question-on-permission-denied-dev-ttyusb0/590/3?u=geeksville) This indicates an OS permission problem for access by your user to the USB serial port. Typically this is fixed by the following. ```shell sudo usermod -a -G dialout ``` If adding your user to the dialout group does not work, you can use the following command to find out which group to add your user to. In this example (from Arch Linux) the group was "uucp" ```shell ❯ ls -al /dev/ttyACM0 crw-rw---- 1 root uucp 166, 0 Jul 20 21:52 /dev/ttyACM0 ``` ### Mac OS Big Sur There is a problem with Big Sur and pyserial. The workaround is to install a newer version of pyserial: ```shell pip3 install -U --pre pyserial ```