Channel Configuration
The Channels config options are: Index, Roles, and Settings. Channel config uses an admin message sending a Channel
protobuf which also consists of a ChannelSettings
or ModuleSettings
protobuf.
Channel Settings (as described on this page) should not be confused with Modem Preset Settings
Modem Preset Settings contain the modem configuration (frequency settings, spreading factor, bandwidth, etc.) used for the LoRa radio. These settings are identical for all channels and can not be unique per channel.
Channel Settings contain information for segregating message groups, configuring optional encryption, and enabling or disabling messaging over internet gateways. These settings are unique and configurable per channel.
Channel Config Values
Index
The channel index begins at 0 and ends at 7.
Indexing can not be modified.
Index | Channel | Default Role | Purpose |
---|---|---|---|
0 | 1 | PRIMARY | Used as default channel |
1 | 2 | DISABLED | User defined |
2 | 3 | DISABLED | User defined |
3 | 4 | DISABLED | User defined |
4 | 5 | DISABLED | User defined |
5 | 6 | DISABLED | User defined |
6 | 7 | DISABLED | User defined |
7 | 8 | DISABLED | User defined |
You can not have DISABLED
channels in-between active channels such as PRIMARY
and SECONDARY
. Active channels must be consecutive.
Role
Each channel is assigned one of 3 roles:
PRIMARY
or1
- This is the first channel that is created for you on initial setup.
- Only one primary channel can exist and can not be disabled.
- Periodic broadcasts like position and telemetry are only sent over this channel.
SECONDARY
or2
- Can modify the encryption key (PSK).
DISABLED
or0
- The channel is no longer available for use.
- The channel settings are set to default.
While you can have a different PRIMARY channel and communicate over SECONDARY channels with the same Name & PSK, a hash of the PRIMARY channel's name sets the LoRa frequency slot, which determines the actual frequency you are transmitting on in the band. To ensure devices with different PRIMARY channel name transmit on the same frequency, you must explicitly set the LoRa frequency slot.
Channel Settings Values
The Channel Settings options are: Name, PSK, Downlink Enabled, and Uplink Enabled. Channel settings are embedded in the Channel
protobuf as a ChannelSettings
protobuf and sent as an admin message.
Name
A short identifier for the channel. (< 12 bytes)
Reserved Name | Purpose |
---|---|
"" (default) | If left empty on the Primary channel, this designates the default channel. |
admin | On Secondary channels, the name admin (case sensitive) designates the admin channel used to administer nodes over the mesh |
Matching channel names are required in order to communicate on the same channel with other devices. Example: If your device is using the channel name LongFast
the device you are attempting to communicate with must also have a channel named LongFast
.
PSK
The encryption key used for private channels.
Hex byte 0x01
for the Primary default
channel.
Must be either 0 bytes (no crypto), 16 bytes (AES128), or 32 bytes (AES256).
Matching PSKs are required in order to communicate on the same channel with other devices. Example: If your device is using a channel with the default PSK of AQ==
the device you are attempting to communicate with must also have a matching channel with the same PSK.
Downlink Enabled
If enabled, messages captured from a public internet gateway will be forwarded to the local mesh.
Set to false
by default for all channels.
Uplink Enabled
If enabled, messages from the mesh will be sent to the public internet through any node's configured gateway.
Set to false
by default for all channels.
Channel Module Settings
The channel module settings options are: position precision. Channel module settings are embedded in the Channel protobuf as a ModuleSettings protobuf and sent as an admin message.
Position Precision
The position_precision
setting allows control of the level of precision for location data that is sent over a particular channel. This can be useful for privacy reasons, where obfuscating the exact location may be desired when sending position data over certain channels.
The position_precision
value is an integer between 0 and 32:
- A value of 0 means that location data is never sent over the given channel.
- A value of 32 means that location data is sent with full precision.
- Values in between indicate the number of bits of precision to be sent.
Some useful values and their approximate precisions:
- 11: Large region, around ±11 kilometers
- 13: City-sized region, around ±3 kilometers
- 16: Neighborhood-level precision, around ±350 meters
The client applications have implemented different levels of precision giving the user a practical range to choose from. Setting across the full range of integers can be done via the Python CLI. See Setting Position Precision for examples on setting different levels of precision using CLI.
Channel Config Client Availability
- Android
- Apple
- CLI
- Web
Android
Channel Config options are available on Android.
The Radio Configuration tab can be used for common tasks:
- View your current channel configuration QR code and URL.
- Quickly create or modify your primary channel.
- Select a modem preset for all your channels i.e.
Long Range / Fast
.
See Android App Usage for more further instruction on setting up your primary channel.
Tap the Channel Name (or the pen icon) to access the Channel Menu:
- Add, remove, or modify secondary channels
- Create or modify encryption keys
- Enable uplink and downlink for individual channels
- Set the position precision value
Apple
A channel editor is available on the iOS, iPadOS and macOS applications at Settings > Radio Configuration > Channels.
CLI
All Channel config options are available in the python CLI. Example commands are below:
Because the device will reboot after each command is sent via CLI, it is recommended when setting multiple values in a config section that commands be chained together as one.
meshtastic --ch-set name "My Channel" --ch-set psk random --ch-set uplink_enabled true --ch-index 4
Name
# without spaces
meshtastic --ch-set name MyChannel --ch-index 0
# with spaces
meshtastic --ch-set name "My Channel" --ch-index 0
PSK
If you use Meshtastic for exchanging messages you don't want other people to see, random
is the setting you should use. Selecting default
or any of the simple
values from the following table will use publicly known encryption keys. They're shipped with Meshtastic source code and thus, anyone can listen to messages encrypted by them. They're great for testing and public channels.
Setting | Behavior |
---|---|
none | Disable Encryption |
default | Default Encryption (use the weak encryption key) |
random | Generate a secure 256-bit encryption key. Use this setting for private communication. |
simple0 - simple254 | Uses a single byte encoding for encryption |
meshtastic --ch-set psk default --ch-index 0
meshtastic --ch-set psk random --ch-index 0
meshtastic --ch-set psk simple15 --ch-index 0
meshtastic --ch-set psk 0x1a1a1a1a2b2b2b2b1a1a1a1a2b2b2b2b1a1a1a1a2b2b2b2b1a1a1a1a2b2b2b2b --ch-index 0
meshtastic --ch-set psk base64:puavdd7vtYJh8NUVWgxbsoG2u9Sdqc54YvMLs+KNcMA= --ch-index 0
Use this to copy and paste the base64
encoded (single channel) key from the meshtastic --info command. Please don't use the omnibus (all channels) code here, it is not a valid key.
meshtastic --ch-set psk none --ch-index 0
Uplink / Downlink
For configuring gateways, please see MQTT
meshtastic --ch-set uplink_enabled true --ch-index 0
meshtastic --ch-set uplink_enabled false --ch-index 0
meshtastic --ch-set downlink_enabled true --ch-index 1
meshtastic --ch-set downlink_enabled false --ch-index 5
Setting Position Precision
This is a per-channel setting. The --ch-index
parameter must be specified to set the position precision for a specific channel, e.g., --ch-index 0
for the primary channel or --ch-index 1
for the secondary channel 1.
meshtastic --ch-set module_settings.position_precision 13 --ch-index 0
meshtastic --ch-set module_settings.position_precision 32 --ch-index 1
Web
All Channel config options are available in the Web UI.