The most interesting thing about the Gnome was that when Sky released it, they enabled RS232 output on the Sky boxes. This gives various information about the current state of the Sky box, which is incredibly useful to anyone trying to integrate a Sky box into a home automation system, data center, and so on.
The two units communicate using 433MHz for data, and choice of a few 2.4 GHz channels for the audio.
The datalink unit connects to the sky box using:
The RF2 protocol seems to be just using the standard IR protocol, as already documented.
Hex bytes ASCII representation 0a 30 31 35 43 45 30 30 30 31 30 31 2d 2d 61 34 .015CE000101--a4The baud rate is 57600, 8N1 (8 data bits, no parity, one stop bit).
| Data | Meaning |
|---|---|
| 0a (ASCII 'LF') | Start of packet |
| 015 | Packet length, excluding the LF but including this field. |
| CE00 | Packet type - ie. entering a channel number in this case (see below for other packet types) |
| 010 | Length of this part of the packet (the "CE000101--a4") - packets can contain multiple data types, although this one only contains one. |
| 1-- | The payload for this part of the packet - in this case the channel number entered so far. |
| a4 | Checksum (for the whole packet, including the LF, but excluding the checksum). It's simply the bytes added together. |
| Data | Meaning |
|---|---|
| SSCN | Current Channel number |
| SSCA | Current Channel name |
| SSDT | Current time |
| SST0 | Start time of current program |
| SSN0 | Current program name
Appears to have some special characters:
|
| SSE0 | Current program description |
| CE00 | Entering channel |
| CEER | Enter channel error (eg. invalid channel number) |
| SYIC | Either -- ('normal') or 8080 (tuned to pin protected channel) |
| SYFS | 0 = Okay, 1 = Audio unavailable |
| SYD1 | System display - a message to be display on gnome screen |
| PUSP | Error - eg. no satellite signal recieved |
| PUCP | Error - eg. enter pin number or "audio unavailable (not subscribed)" |
| SYST | 0 = sky box powered on, 1 = powered off |
| SYIA | 0 = leaving interactive mode, 1 = entered interactive mode (ie. when you press the 'red' key on remote) |
| SSEI | Sky+ operations (eg. 'Pause', 'Rewind', 'Fast Forward', 'Playback') |
The packets are sent whenever a relevant change on the box occurs, no matter whether the change was requested by the gnome or not.
As well as that, every 60 seconds the sky box sends out a packet - this is how the 'clock' on the gnome is updated!
The packet contains:
00000000 0a 32 33 32 53 53 43 4e 30 31 30 32 37 30 53 53 |.232SSCN010270SS| 00000010 43 41 30 30 39 46 58 53 53 44 54 30 32 36 20 32 |CA009FXSSDT026 2| 00000020 2e 30 36 70 6d 20 53 61 74 20 31 32 20 4e 6f 76 |.06pm Sat 12 Nov| 00000030 20 53 53 54 30 30 31 33 32 2e 30 30 70 6d 53 53 | SST00132.00pmSS| 00000040 4e 30 30 31 32 86 4a 41 47 87 53 53 45 30 31 35 |N0012.JAG.SSE015| 00000050 37 41 64 6d 69 72 61 6c 20 43 68 65 67 77 69 64 |7Admiral Chegwid| 00000060 64 65 6e 20 61 6e 64 20 43 6c 61 79 74 6f 6e 20 |den and Clayton | 00000070 57 65 62 62 20 6d 61 6b 65 20 61 6e 20 75 6e 6c |Webb make an unl| 00000080 69 6b 65 6c 79 20 74 65 61 6d 20 77 68 65 6e 20 |ikely team when | 00000090 74 68 65 79 20 6a 6f 69 6e 20 66 6f 72 63 65 73 |they join forces| 000000a0 20 74 6f 20 73 61 76 65 20 61 20 43 49 41 20 61 | to save a CIA a| 000000b0 67 65 6e 74 20 66 72 6f 6d 20 49 74 61 6c 69 61 |gent from Italia| 000000c0 6e 20 74 65 72 72 6f 72 69 73 74 73 2e 20 53 74 |n terrorists. St| 000000d0 61 72 72 69 6e 67 3a 20 43 61 74 68 65 72 69 6e |arring: Catherin| 000000e0 65 20 42 65 6c 6c 2e 62 33 |e Bell.b3|Splitting this up, the various sub-packets are:
Type Len Data ==== === ==== SSCN 010 270 SSCA 009 FX SSDT 026 2.06pm Sat 12 Nov SST0 013 2.00pm SSN0 012 JAG SSE0 157 Admiral Chegwidden and Clayton Webb make an unlikely team when they join forces to save a CIA agent from Italian terrorists. Starring: Catherine Bell.or fully decoded:
| Data type | Value |
|---|---|
| Channel number | 270 |
| Channel name | FX |
| Current time | 2.06pm Sat 12 Nov |
| Start of program | 2.00pm |
| Program name | JAG |
| Program description | Admiral Chegwidden and Clayton Webb make an unlikely team when they join forces to save a CIA agent from Italian terrorists. Starring: Catherine Bell. |
Note that you will occasionally see other data on the serial port, mostly during bootup and when entering/exitting interactive mode.
This could just be debug code left in the software, and are easily ignored if you just ensure your parser is robust.
I thought other people might find it useful to see other solutions people have produced that use this data.
If you know of any others, drop me an email and I'll be more than happy to add them to this list.
If anyone spots an error or has any additions to the above please drop me an email!
If you use the above information, I'd appreciate if you'd provide a credit and a link to this site. I'd also be interested to hear of any uses anyone puts the above information too.