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9 The control unit broadcasts data packets across the track.
10 The packets are 9 bytes long, and the structure is the following:
12 0x55 packet_type data_byte1..6 crc
14 The Ole Seeberg's interface adds 0x05 (05 = O.S. :-) after each packet.
15 This byte can be safely ignored.
17 There can be noise on the track, so sometimes the packets are received
18 by a reader with an incorrect checksum. Those should be discarded.
20 The bus reader apparently does not report packets which are sent by
28 Format: 0x55 0xAA N1 N2 0xF0 0xF0 0xF0 0xF0 CRC
30 Sent twice after the car crosses the finish line. This is a message
31 to the car instructing it to send its ID after the given delay.
32 The delay is the ratio of the N1 and N2 numbers. No need to handle
33 this, it is for cars, not race management.
35 N1, N2 - fraction specifiying the bus free time. My Pit box with 020 firmware
36 sends the first packet with 0x0C 0x06, and the second one with
40 55 AA 0C 06 F0 F0 F0 F0 7B
41 55 AA 18 06 F0 F0 F0 F0 93
44 0xCC - car programming
45 ----------------------
46 Format: 0x55 0xCC CTRL 0xFE 0xFF 0xFF 0xFF 0xFF CRC
48 Sent twice when matching the car to the particular controller.
53 Bits 2-0 - number of the controller (starting from 0)
61 Format: 0x55 0xD0 0xFF N1 N2 0xAA 0xAA 0xAA CRC
63 N1, N2 forms the ratio, probably used as a challenge for car control units
66 55 D0 FF 0A 05 AA AA AA AD
71 Format: 0x55 0xD3 P0-P5 CRC
73 Sent after passing the start/finish line for the first time in a race
74 and then every 300 ms.
76 P0-P5: one byte for each position, starts with the leader.
77 0xFF means there is no car on this position (for example,
78 when not all cars have passed the start line)
79 Bit 7 - 1 if the car is more than 15 laps behind the leader
80 Bits 6-3 - number of laps behind the leader (0-15, set to 0
81 when bit 7 is set to 1)
82 Bits 2-0 - vehicle number (0-5)
85 55 D3 81 FF FF FF FF FF 2C
90 Format: 0x55 0xD4 ID R1 R2 MS T1 T2 CRC
92 Sent after passing the finish line and then every 300 ms.
93 Lap count and last lap time of the specified vehicle.
96 R1: Round number - higher byte
97 R2: Round number - lower byte (bit 0 is always zero)
100 Bit 3 - least significant bit of T1
103 Bit 0 - least significant bit of R2
104 T1: Lap time - higher byte (bit 0 is always zero)
105 T2: Lap time - lower byte
107 So the lap number is 256*R1 + R2 + MS & 0x01, and the time is
108 256*T1 + (MS & 0x08 ? 1 : 0)
111 55 D4 01 00 00 01 00 00 59 (round 1 - after crossing the start line)
112 55 D4 01 00 02 08 00 E8 32 (round 2)
113 55 D4 01 00 02 0D 00 B6 3C (round 3)
114 55 D4 01 00 04 0C 04 98 69 (round 4)
116 32.203 55 d4 02 00 06 0d 00 fe 4f 05 # Car 2 round 7 time ff ..
117 32.315 55 d4 02 00 06 01 00 00 a9 05 # Car 2 round 7 time 00
118 34.005 55 d4 02 00 06 09 fe fe 13 05 # Here the back button has been presed
124 Format: 0x055 0xD5 DI R2-R0 0xFF 0xFF CRC
126 Sent when the Start button is pressed for two seconds, i.e. before
127 the start of the race.
129 DI - lap counting direction. 0x00 means counting from 0 upwards,
130 0xFF means counting from preset number of laps downwards.
131 R2-R0 - number of laps. Only lower 4 bits are used, so the count
132 can be obtained as 256*R2 + 16*R1 + R0
135 55 D5 00 FF FF FF FF FF 83
136 55 D5 FF 00 00 04 FF FF CF
141 Format: 0x55 0xD6 F0-F2 N1 N2 B CRC
143 Sent about every 500 ms, current fuel level
145 F0-F2 - encodes the fuel level for each car in 4 bits (values 0-8);
146 car 0 is in higher-order bits of F0 (F0 >> 4), car 5
147 is in lower-order bits of F2 (F2 & 0x0F).
148 N1,N2 - fuel consumption ratio (e.g. 0x14 0x50 means 0.25, 0x00 0x50
149 means the race w/o fuel consumption).
150 B - 0xAA, but the source reports that 0xFF has been rarely seen here as well.
153 55 D6 88 88 88 00 50 AA 3D
154 55 D6 88 18 88 14 50 AA 7F
159 Format: 0x55 0xD7 CT BR 0x83 0x93 0xDB 0xFF CRC
161 CT - the controller which had the back button pressed (0-5)
162 BR - brake level (0x00 - 0 %, 0x02 - 50 %, 0x04 - 100 %)
170 Format: 0x55 0xDB R2-R0 NR 0xFF 0xFF CRC
172 Sent after the start of the qualification.
174 R2-R0 - number of laps. Only lower 4 bits are used, so the count
175 can be obtained as 256*R2 + 16*R1 + R0
176 NR - number of cars participating in the qualification
179 0xDC - end of the race
180 ----------------------
181 Format: 0x55 0xDC 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF CRC
183 Sent twice when the last vehicle crosses the finish line or the race is stopped.
186 55 DC FF FF FF FF FF FF DF
191 Format: 0x55 0xDD 0x00 0xAA 0xAA 0xAA 0xAA 0xAA CRC
193 Sent twice after the reset packet (0xD0) has been sent twice.
196 55 DD 00 AA AA AA AA AA 42
199 0xDE - display change
200 ---------------------
201 Format: 0x55 0xDE WE 0xFF 0xFF 0xFF 0xFF 0xFF CRC
205 Sent in the RES mode: after the SELECT button is pressed for the
206 first time, no packet is sent. The second time the packet with WE = 0
207 is sent, the third time two packets are sent (one weith WE = 0 and
208 one with WE = 1), and the fourth time two packets are sent
209 (one with WE = 1 and one with WE = 0).
217 Format: 0x05 0xEE R0-R5 CRC
219 Sent after the car crosses the finish line and sends back its ID.
221 R0-R5 - one byte for each car. 0xE7 means that this car has crossed the
222 finish line, every other value means it did not cross it:
223 0xAA is sent for unconnected controllers.
226 55 EE F0 E7 F0 AA AA AA 3C
227 55 EE FE FE E7 AA AA AA 1E # Car 2 crosses normal finish line
228 55 EE 02 00 E7 01 00 00 CF # Car 2 drives through pit lane
229 55 EE 82 FF E7 FF FF Ff 90 # Car 2 enters pit lane too fast
230 55 EE F0 F0 E7 AA AA AA B1 # Car 2 enters pit lane
231 55 EE 83 78 E7 14 50 AA 04 # Car 2 enters pit lane too fast?
235 0xFF - controller status
236 ------------------------
237 Format: 0x55 0xFF R0-R5 CRC
239 Sent approximately every 102 ms, or when the change is detected.
241 R0-R5: For each controller there is one byte.
242 0xAA - set when the controller is not connected
243 otherwise, the bits have the following meaning:
246 Bit 5 - lights (0 = on, 1 = off)
247 (note the lights setting is reported for each controller,
248 even though the control unit can set it only for all cars
250 Bit 4 - back button (0 = pressed, 1 = not pressed)
251 Bits 3-0 - throttle (values 0-12 in normal mode, 0-8 in junior mode,
252 and 0-6 in the pit lane)
255 55 FF F0 F0 F0 AA AA AA 7D
256 - controllers 1-3 present and idle, 4-6 not connected