Remove all varint/zigzag encoding. Every field is now struct.pack/unpack
with fixed-size little-endian format strings. RadioConfig is a single
struct.pack('<IBBBHB', ...) call. Response decoding uses struct.unpack_from
with known offsets. No encoding helpers needed beyond struct.
- Each board exports TX_POWER_RANGE constant (min, max dBm)
- RadioConfig::validate() uses the board's range, not hardcoded limits
- TX_POWER_MAX sentinel (-128 on the wire) means "use board's maximum"
— resolved to the actual max before storing config
- GetConfig returns the resolved actual power, not the sentinel
- Default configs in examples use TX_POWER_MAX
- Protocol docs updated
ROOT CAUSE: postcard encodes u8 and i8 as raw bytes, NOT varint/zigzag.
The Python encoders used varint() for u8 and zigzag() for i8. For small
values this was silently correct (varint(7) == raw byte 7), but for
tx_power_dbm: zigzag(14) = 28, which the new validation correctly
rejected as out of range (-9..22). This was a pre-existing bug masked
by the absence of validation.
Fix all RadioConfig field encoders in both donglora.py and meshcore_rx.py.
Fix docs/PROTOCOL.md to correctly document i8 as raw byte, not zigzag.
Restore full config validation.
MeshCore is a protocol implementation ON TOP of DongLoRa, not part of the
dongle itself. Moving it to examples/ makes the separation clear while
keeping it accessible as a real-world usage example.
swaits