Using this module, a client device can ask a special Store & Forward Router to resend text messages after the client has been temporarily not in LoRa range of the mesh.
:::info
Only ESP32 based devices with onboard PSRAM like the T-Beam and T3S3 can be a Store & Forward Router. Requires the device to use at least firmware version 2.2.23 and to be set as a `ROUTER` or `ROUTER_CLIENT`.
When a client device requests the history from the Store & Forward Router, the router will resend the text messages over LoRa that it has received. The router will only return messages that are within the time window the client has requested up to the maximum number of messages configured for the router.
The router does not know which messages the client device actually missed, so it is possible that you receive duplicates.
- One ESP32 device with PSRAM configured as `ROUTER` or `ROUTER_CLIENT`.
- Two others will be regular clients. If one client sends a text message when the other is not in range, the other can request the history from the router to receive the missed message when it is back in range.
Currently implemented in the Android and Apple apps version 2.2.23 and higher. To request the history from the Store & Forward Router, for Android it is required to send it a direct message containing the text "SF" (without quotes). The router will then respond with the requested messages.
The Apple apps will also show whether a node is a Store & Forward Router in the node list after it heard the heartbeat. You can then long press the node and select "Client History" to request the history from the router.
The Store & Forward Router sends a periodic message onto the network. This allows connected devices to know that a router is in range and listening to received messages. A client like Android, iOS, or Web can (if supported) indicate to the user whether a store and forward router is available.
Set this to the maximum number of records the router will save. Best to leave this at the default (`0`) where the module will use 2/3 of your device's available PSRAM. This is about 11,000 records.
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.