From: Jan "Yenya" Kasprzak Date: Thu, 2 Dec 2010 00:58:49 +0000 (+0100) Subject: Protocol documentation. X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=commitdiff_plain;h=09f6bee9b34515e38dcf40a5e56b3bd327f7ba7e;p=slotcarman.git Protocol documentation. --- diff --git a/protocol.txt b/protocol.txt new file mode 100644 index 0000000..416dea3 --- /dev/null +++ b/protocol.txt @@ -0,0 +1,249 @@ +Derived from +http://translate.google.com/translate?js=n&prev=_t&hl=cs&ie=UTF-8&layout=2&eotf=1&sl=de&tl=en&u=http%3A%2F%2Fslotbaer.de%2Findex.php%2Fscx-digital%2F63-scx-digital-daten-protokoll&act=url + +Original source +http://slotbaer.de/index.php/scx-digital/63-scx-digital-daten-protokoll + +Outline +======= +The control unit broadcasts data packets across the track. +The packets are 9 bytes long, and the structure is the following: + +0x55 packet_type data_byte1..6 crc + +The Ole Seeberg's interface adds 0x05 (05 = O.S. :-) after each packet. +This byte can be safely ignored. + +There can be noise on the track, so sometimes the packets are received +by a reader with an incorrect checksum. Those should be discarded. + +The bus reader apparently does not report packets which are sent by +the cars. + +Packet types +============ + +0xAA - bus free time +-------------------- +Format: 0x55 0xAA N1 N2 0xF0 0xF0 0xF0 0xF0 CRC + +Sent twice after the car crosses the finish line. This is a message +to the car instructing it to send its ID after the given delay. +The delay is the ratio of the N1 and N2 numbers. No need to handle +this, it is for cars, not race management. + +N1, N2 - fraction specifiying the bus free time. My Pit box with 020 firmware + sends the first packet with 0x0C 0x06, and the second one with + 0x18 0x06 + +Example: +55 AA 0C 06 F0 F0 F0 F0 7B +55 AA 18 06 F0 F0 F0 F0 93 + + +0xCC - car programming +---------------------- +Format: 0x55 0xCC CTRL 0xFE 0xFF 0xFF 0xFF 0xFF CRC + +Sent twice when matching the car to the particular controller. + +CTRL: + Bit 7 - always 1 + Bits 6-3 - always 0 + Bits 2-0 - number of the controller (starting from 0) + +Example: +TBD + + +0xD0 - reset +------------ +Format: 0x55 0xD0 0xFF N1 N2 0xAA 0xAA 0xAA CRC + +N1, N2 forms the ratio, probably used as a challenge for car control units + +Example: +55 D0 FF 0A 05 AA AA AA AD + + +0xD3 - standings +---------------- +Format: 0x55 0xD3 P0-P5 CRC + +Sent after passing the start/finish line for the first time in a race +and then every 300 ms. + +P0-P5: one byte for each position, starts with the leader. + 0xFF means there is no car on this position (for example, + when not all cars have passed the start line) + Bit 7 - 1 if the car is more than 15 laps behind the leader + Bits 6-3 - number of laps behind the leader (0-15, set to 0 + when bit 7 is set to 1) + Bits 2-0 - vehicle number (0-5) + +Example: +55 D3 81 FF FF FF FF FF 2C + + +0xD4 - lap time +--------------- +Format: 0x55 0xD4 ID R1 R2 MS T1 T2 CRC + +Sent after passing the finish line and then every 300 ms. +Lap count and last lap time of the specified vehicle. + +ID: car number (0-5) +R1: Round number - higher byte +R2: Round number - lower byte (bit 0 is always zero) +MS: miscellaneous + Bits 7-4 - always 0 + Bit 3 - least significant bit of T1 + Bit 2 - unknown + Bit 1 - unknown + Bit 0 - least significant bit of R2 +T1: Lap time - higher byte (bit 0 is always zero) +T2: Lap time - lower byte + +So the lap number is 256*R1 + R2 + MS & 0x01, and the time is +256*T1 + (MS & 0x08 ? 1 : 0) + +Example: +55 D4 01 00 00 01 00 00 59 (round 1 - after crossing the start line) +55 D4 01 00 02 08 00 E8 32 (round 2) +55 D4 01 00 02 0D 00 B6 3C (round 3) +55 D4 01 00 04 0C 04 98 69 (round 4) + + +0xD5 - race start +----------------- +Format: 0x055 0xD5 DI R2-R0 0xFF 0xFF CRC + +Sent when the Start button is pressed for two seconds, i.e. before +the start of the race. + +DI - lap counting direction. 0x00 means counting from 0 upwards, + 0xFF means counting from preset number of laps downwards. +R2-R0 - number of laps. Only lower 4 bits are used, so the count + can be obtained as 256*R2 + 16*R1 + R0 + +Example: +55 D5 00 FF FF FF FF FF 83 + + +0xD6 - fuel level +----------------- +Format: 0x55 0xD6 F0-F2 N1 N2 B CRC + +Sent about every 500 ms, current fuel level + +F0-F2 - encodes the fuel level for each car in 4 bits (values 0-8); + car 0 is in higher-order bits of F0 (F0 >> 4), car 5 + is in lower-order bits of F2 (F2 & 0x0F). +N1,N2 - fuel consumption ratio (e.g. 0x14 0x50 means 0.25, 0x00 0x50 + means the race w/o fuel consumption). +B - 0xAA, but the source reports that 0xFF has been rarely seen here as well. + +Example: +55 D6 88 88 88 00 50 AA 3D +55 D6 88 18 88 14 50 AA 7F + + +0xD7 - brake setting +-------------------- +Format: 0x55 0xD7 CT BR 0x83 0x93 0xDB 0xFF CRC + +CT - the controller which had the back button pressed (0-5) +BR - brake level (0x00 - 0 %, 0x02 - 50 %, 0x04 - 100 %) + +Example: +TBD + + +0xDB - qualification +-------------------- +Format: 0x55 0xDB R2-R0 NR 0xFF 0xFF CRC + +Sent after the start of the qualification. + +R2-R0 - number of laps. Only lower 4 bits are used, so the count + can be obtained as 256*R2 + 16*R1 + R0 +NR - number of cars participating in the qualification + + +0xDC - end of the race +---------------------- +Format: 0x55 0xDC 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF CRC + +Sent twice when the last vehicle crosses the finish line or the race is stopped. + +Example: +55 DC FF FF FF FF FF FF DF + + +0xDD - race start +----------------- +Format: 0x55 0xDD 0x00 0xAA 0xAA 0xAA 0xAA 0xAA CRC + +Sent twice after the reset packet (0xD0) has been sent twice. + +Example: +55 DD 00 AA AA AA AA AA 42 + + +0xDE - display change +--------------------- +Format: 0x55 0xDE WE 0xFF 0xFF 0xFF 0xFF 0xFF CRC + +WE - 0 or 1 + +Sent in the RES mode: after the SELECT button is pressed for the +first time, no packet is sent. The second time the packet with WE = 0 +is sent, the third time two packets are sent (one weith WE = 0 and +one with WE = 1), and the fourth time two packets are sent +(one with WE = 1 and one with WE = 0). + +Example: +TBD + + +0xEE - finish line +------------------ +Format: 0x05 0xEE R0-R5 CRC + +Sent after the car crosses the finish line and sends back its ID. + +R0-R5 - one byte for each car. 0xE7 means that this car has crossed the + finish line, every other value means it did not cross it: + 0xAA is sent for unconnected controllers. + My pit box with 020 firmware has been seen sending either + 0xF0 or 0xFE values as well + +Example: +55 EE F0 E7 F0 AA AA AA 3C +55 EE FE FE E7 AA AA AA 1E + + +0xFF - controller status +------------------------ +Format: 0x55 0xFF R0-R5 CRC + +Sent approximately every 102 ms, or when the change is detected. + +R0-R5: For each controller there is one byte. + 0xAA - set when the controller is not connected + otherwise, the bits have the following meaning: + Bit 7 - always 1 + Bit 6 - always 1 + Bit 5 - lights (0 = on, 1 = off) + (note the lights setting is reported for each controller, + even though the control unit can set it only for all cars + at once) + Bit 4 - back button (0 = pressed, 1 = not pressed) + Bits 3-0 - throttle (values 0-12 in normal mode, 0-8 in junior mode, + and 0-6 in the pit lane) + +Example: +55 FF F0 F0 F0 AA AA AA 7D +- controllers 1-3 present and idle, 4-6 not connected + +