This is a LoRa repeater that repeats any LoRa HAB packet that it receives. The receive and transmit parameters (frequency, mode etc.) are programmable via serial/USB and are stored in EEPROM; a companion application is available to make this easy and is available for Windows.
Connections are:
Arduino 0 (Tx) - Serial for configuration Arduino 1 (Rx) - Serial for configuration
Arduino 4 - LoRa RST Arduino 7 - LoRa DIO0 Arduino 8 - LoRa NSS Arduino 11 - LoRa MOSI Arduino 12 - LoRa MISO Arduino 13 - LoRa SCK
The serial connection is 57600 baud and will send status information and incoming LoRa packets without being polled. Each of these is of the form
something = value <CR><LF>
The "something"s are:
- CurrentRSSI=<RSSI>
- Message=<telemetry>
- Hex=<hex packet e.g. SSDV>
- FreqErr=<error in kHz>
- PacketRSSI=<RSSI>
- PacketSNR=<SNR>
The serial interface accepts a few commands, each of the form
~ Command [value] <CR>
(a trailing <LF> can be sent but is ignored). Accepted commands are responded to with an OK (* <CR> <LF>) and rejected commands (unknown command, or invalid command value) with a WTF (? <CR> <LF>)
Commands that set radio parameters are in upper case for the receiver or lower case for the transmitter. e.g. ~F434.250 sets the receive frequency to 434.250, and ~f434/450 sets the transmit frequency to 434.450.
The radio commands (upper case for receiver, lower case for transmitter) are:
- F<frequency in MHz>
- B<bandwidth>
- E<error coding from 5 to 8>
- S<spreading factor from 6 to 11>
- I<1=implicit mode, 0=explicit mode>
- L(low data rate optimisation: 1=enable, 0=disable)
The other configuration commands are:
- P<PPM>
- R<1=repeating on, 0=repeating off>
Finally, "!" stores the current settings in EEPROM, "^" resets all settings to those in EEPROM, and then lists those settings, "*" resets all settings to defaults, stores those in EEPROM and lists them, and "?" lists the current values of all settings.
Bandwidth value strings can be 7K8, 10K4, 15K6, 20K8, 31K25, 41K7, 62K5, 125K, 250K, 500K
09/04/2019 V1.0.1 - Updated README only
05/04/2019 V1.0.1 - First version