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LoRa Configuration

The LoRa config options are: Region, Modem Preset, Max Hops, Transmit Power, Bandwidth, Spread Factor, Coding Rate, Frequency Offset, Transmit Enabled, Channel Number and Ignore Incoming Array. LoRa config uses an admin message sending a Config.LoRa protobuf.

note

In order to communicate fully, devices within a mesh must have identical settings for Region and Modem Preset, or identical custom Modem settings.

LoRa Config Values​

note

You must set your device's lora.region setting. This will ensure that you are operating within the legal limits for your area.

Region​

Sets the region for your node. Default is unset. As long as this is not set, the node screen will display a message and not transmit any packets.

Region CodeDescription
UNSETUnset
USUnited States
EU_433European Union 433MHz
EU_868European Union 868MHz
CNChina
JPJapan
ANZAustralia & New Zealand
KRKorea
TWTaiwan
RURussia
INIndia
NZ_865New Zealand 865MHz
UA_433Ukraine 433MHz
UA_868Ukraine 868MHz
THThailand
LORA_242.4 GHz band worldwide
info

EU_433 and EU_868 have to adhere to an hourly duty cycle limitation of 10%. Your device will stop transmitting if you reach it, until it is allowed again.

Modem Preset​

Default is unset which equates to LONG_FAST. Presets are pre-defined modem settings (Bandwidth, Spread Factor, and Coding Rate) which influence both message speed and range. The default will provide a strong mixture of speed and range, for most users.

The presets are designed to provide further options for optimizing either speed (and reduced network congestion) or range, which can be useful for two real world scenarios:

  1. A high number of devices exist in the mesh, or messages are sent very frequently. Faster speeds (and therefore lower radio time per device) can help with mesh network congestion.
  2. Maximum range is desired, for long range scenarios where a several second delay in message receipt is acceptable (for instance, attempting to send messages from a town to a distant mountain top).

The Presets available as as follows, and follow a linear pattern of Fastest <--> Slowest, and Shortest <--> Longest range:

  1. SHORT_FAST (Fastest, highest bandwidth, lowest airtime, shortest range)

  2. SHORT_SLOW

  3. MEDIUM_FAST

  4. MEDIUM_SLOW

  5. LONG_FAST (Default)

  6. LONG_SLOW

  7. VERY_LONG_SLOW (Slowest, lowest bandwidth, highest airtime, longest range)

Max Hops​

Maximum number of hops. This can't be greater than 7. Default is 3 which should be fine for most applications. Really, 3 is fine.

Transmit Power​

If zero then, use default max legal continuous power (i.e. something that won't burn out the radio hardware)

In most cases you should use zero here. Units are in dBm.

Bandwidth​

Bandwidth in MHz

Certain bandwidth numbers are 'special' and will be converted by the device firmware to the appropriate floating point value: 31 -> 31.25MHz

Spread Factor​

A number from 7 to 12. Indicates the number of chirps per symbol as 1<<spread_factor.

Coding Rate​

The denominator of the coding rate. ie for 4/5, the value is 5. 4/8 the value is 8.

Frequency Offset​

This parameter is for advanced users with advanced test equipment, we do not recommend most users use it.

A frequency offset that is added to to the calculated band center frequency. Used to correct for crystal calibration errors.

Transmit Enabled​

Allows you to enable and disable transmit (TX) from the LoRa radio. Useful for hot-swapping antennas and other tests.

Defaults to true

Channel Number​

This is controlling the actual hardware frequency the radio is transmitting on. A channel number between 1 and NUM_CHANNELS (whatever the max is in the current region). If this is ZERO/UNSET then the rule is "use the old channel name hash based algorithm to derive the channel number".

Ignore Incoming Array​

For testing it is useful sometimes to force a node to never listen to particular other nodes (simulating radio out of range). All nodenums listed in the ignore_incoming array will have packets they send dropped on receive (by router.cpp)

Override Duty Cycle Limit​

Setting this option to 'true' means the device will ignore the hourly duty cycle limit in Europe. This means that you might violate regulations if the device transmits too much. By default, this option is set to 'false,' which means the device will stop sending data when it reaches the hourly limit and will start again when it is allowed to do so.

LoRa Config Client Availability​

info

Configuration of Region, Modem Preset and Hop Limit is available on iOS, iPadOS and macOS at Settings > Radio Configuration > LoRa.