Let's separate the setup of the badges from their main app. Make an app to program the EEPROM from a RAK4631. Accept commands from Serial and read / write data from the RAK4631 to the EEPROM.
/name xxxxxxxx --> Initialize with a name xxxxxxx and a new UUID
/name? --> read back name & UUID
/read --> read back name & UUID
Binary, LPP style, but without field markers. The idea is to have a fixed format that saves as mich space as possible.
- Message UUID (4 bytes)
- From ID (1 byte) – Fewer senders
- To ID (2 bytes) - 65535 possible recipients (0 = *)
- Resend Counter (1 byte) – Limit resends to X (3?) resends. If counter = limit, do not resend further.
- Message Type (1 byte) – Canned message (0x00) or free-style (byte = length).
- Message contents (1 byte..XX bytes) 1 byte for canned.
A pre-canned message will be 4+1+2+1+1+1, ie ten bytes. THIS can be sent at any SF/BW combination...
| UUID | From | To | Resend | Type | Contents |
|---|---|---|---|---|---|
| 00.01.02.03 | 0F | AB.CD | 00 | 00 | 00 |
- 00 Call your office/service
- 01 (Followed by 5 bytes) Call this number
- Example:
| UUID | From | To | Resend | Type | Contents | Extra |
|---|---|---|---|---|---|---|
| 00.01.02.03 | 0F | AB.CD | 00 | 00 | 01 | 06.30.59.1e.4b |
| 06.4889.3075 |
Two phone digits are encoded in one byte. 5 bytes needed for a full phone number.
- 02 Come back to office
etc, etc... Yours to decide.
Make a JSON file that will be loaded by the Xojo app, and a .h file that will be loaded by the Arduino app. OR, maybe, write them to the EEPROM too.
