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| -rw-r--r-- | doc/telemetry.xsl | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/doc/telemetry.xsl b/doc/telemetry.xsl index 73a9f900..fa66bff9 100644 --- a/doc/telemetry.xsl +++ b/doc/telemetry.xsl @@ -705,6 +705,74 @@ </section> </section> <section> + <title>TeleDongle packet format</title> + <para> + TeleDongle does not do any interpretation of the packet data, + instead it is configured to receive packets of a specified + length (32 bytes in this case). For each received packet, + TeleDongle produces a single line of text. This line starts with + the string "TELEM " and is followed by a list of hexadecimal + encoded bytes. + </para> + <programlisting>TELEM 224f01080b05765e00701f1a1bbeb8d7b60b070605140c000600000000000000003fa988</programlisting> + <para> + The hexadecimal encoded string of bytes contains a length byte, + the packet data, two bytes added by the cc1111 radio receiver + hardware and finally a checksum so that the host software can + validate that the line was transmitted without any errors. + </para> + <table> + <tgroup cols='4'> + <colspec align="center" colwidth="2*" colname="offset"/> + <colspec align="center" colwidth="*" colname="name"/> + <colspec align="center" colwidth="*" colname="value"/> + <colspec align="center" colwidth="5*" colname="description"/> + <thead> + <row> + <entry align='center'>Offset</entry> + <entry align='center'>Name</entry> + <entry align='center'>Example</entry> + <entry align='center'>Description</entry> + </row> + </thead> + <tbody> + <row> + <entry>0</entry> + <entry>length</entry> + <entry>22</entry> + <entry>Total length of data bytes in the line. Note that + this includes the added RSSI and status bytes</entry> + </row> + <row> + <entry>1 ·· length-3</entry> + <entry>packet</entry> + <entry>4f ·· 00</entry> + <entry>Bytes of actual packet data</entry> + </row> + <row> + <entry>length-2</entry> + <entry>rssi</entry> + <entry>3f</entry> + <entry>Received signal strength. dBm = rssi / 2 - 74</entry> + </row> + <row> + <entry>length-1</entry> + <entry>lqi</entry> + <entry>a9</entry> + <entry>Link Quality Indicator and CRC status. Bit 7 + is set when the CRC is correct</entry> + </row> + <row> + <entry>length</entry> + <entry>checksum</entry> + <entry>88</entry> + <entry>(0x5a + sum(bytes 1 ·· length-1)) % 256</entry> + </row> + </tbody> + </tgroup> + </table> + </section> + <section> <title>History and Motivation</title> <para> The original AltoOS telemetry mechanism encoded everything |