Differences

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--- tracking:reader [2012/04/25 23:37] – [packet format] correct type byte to be hex sec
+++ tracking:reader [2012/09/04 18:11] (current) – sec
@@ Line 8: / Line 8: @@
 ===== Replacement =====
-We use r0kets as readers. Their sensitivity is worse and they are very directional, but it's good enough to play around with it.
+We sometimes use r0kets as readers. Their sensitivity is worse and they are very directional, but it's good enough to play around with it.
 ==== Current version ====
 bridge firmware flashed on r0ket, packet dump read via USB serial and sent on with a small script.
-  * e.g. [[https://github.com/r0ket/r0ket/blob/master/tools/mesh/beacon-udp.pl|beacon-udp.pl]]
+  * e.g. [[https://github.com/r0ket/r0ket/blob/master/tools/reader/beacon-udp.pl|beacon-udp.pl]]
+  * or a compiled version of [[https://github.com/r0ket/r0ket/blob/master/tools/reader/obreader.c|obreader.c]] if perl is too slow
 ====== packet format ======
@@ Line 26: / Line 27: @@
 | 0x01 | ::: | ::: |
 | 0x02 | proto | BEACONLOG_SIGHTING == 1 |
-| 0x03 | interface | 0 or 1 for official reader, 0 always for us |
+| 0x03 | interface | 0 or 1 on official reader, 0 always in our code |
 | 0x04 | readerid | needs to be added to src/bmReaderPositions.h |
 | 0x05 | ::: | ::: |
@@ Line 39: / Line 40: @@
 | 0x0e | ::: | ::: |
 | 0x0f | ::: | ::: |
+this is followed by the raw packet as captured by the rf interface.
 For the reference, the openbeacon packet format looks like this:
@@ Line 46: / Line 49: @@
 | **byte** | **name** | **description** |
 | 0x00 | len | length of the packet (usually 16) |
-| 0x01 | type | openbeacon = 0x17 |
+| 0x01 | type | openbeacon (0x17) |
 | 0x02 | button | sputnik "button" press. R0ket=0xff which makes openbeacon-tracker output "button=true" |
-| 0x03 | strength | 0x00 / 0x55 / 0xaa / 0xff (low to high) rf sending stregth used |
+| 0x03 | strength | 0x00 / 0x55 / 0xaa / 0xff (low to high) rf sending strength used |
 | 0x04 | idx | monotonically increading sequence. Original sputnik dies after 0xffffffff |
 | 0x05 | ::: | ::: |
@@ Line 85: / Line 88: @@
 fi
 </code>
+Our reader implementation also send a heartbeat packet every second. This packet has the standard reader header, but the last 16 bytes are just:
+| **byte** | **name** | **description** |
+| 0x00 | type | RFBPROTO_READER_ANNOUNCE (22)  |
+| 0x01 | unused | 0x0 |
+| ...  | ::: | ::: |
+| 0x0d | ::: | ::: |
+| 0x0e | crc | ccitt16(bytes[0x0-0xd]) |
+| 0x0f | ::: | ::: |