You can make the bytes as long as you like and certainly 16 bits is fine using b0/b1 as w0 etc. My data packets are 10 bytes but any number will do.
Re Manchester coding, this code does use up a fair bit of memory, especially on an 08M. Clearly sending a row of low value numbers (1,2,3 etc) is not good as the binary has a bias towards zeros (00000001, 00000010, 00000011). One system that uses less code is just to send the inverse of each byte eg 255- the value. So if sending 00000001 then send 11111110 as the next byte and discard alternate bytes (or use these bytes as part of a checksum system).
Re Rigidig's 9 digit problem, see <A href='http://www.geocities.com/drvernacula/315_mhz_solar_powered_radio_rptr.htm' Target=_Blank>External Web Link</a> for some code (near the bottom of the page). Sends all the registers of the picaxe. Note lots of "U"s as the higher power modules seem to need more. The multiple "U"s also ought to please our NZ friends (sorry, couldn't resist the pun). Checksums are also very helpful if there are several modules transmitting nearby. It helps to define if the unreliability problem is due to interference or due to the digit string being too long. I haven't been game to go much longer than these strings, though they do seem 100% reliable over 100 metres with the higher power modules.
Edited by - Dr_Acula on 21/08/2007 14:40:16
Re Manchester coding, this code does use up a fair bit of memory, especially on an 08M. Clearly sending a row of low value numbers (1,2,3 etc) is not good as the binary has a bias towards zeros (00000001, 00000010, 00000011). One system that uses less code is just to send the inverse of each byte eg 255- the value. So if sending 00000001 then send 11111110 as the next byte and discard alternate bytes (or use these bytes as part of a checksum system).
Re Rigidig's 9 digit problem, see <A href='http://www.geocities.com/drvernacula/315_mhz_solar_powered_radio_rptr.htm' Target=_Blank>External Web Link</a> for some code (near the bottom of the page). Sends all the registers of the picaxe. Note lots of "U"s as the higher power modules seem to need more. The multiple "U"s also ought to please our NZ friends (sorry, couldn't resist the pun). Checksums are also very helpful if there are several modules transmitting nearby. It helps to define if the unreliability problem is due to interference or due to the digit string being too long. I haven't been game to go much longer than these strings, though they do seem 100% reliable over 100 metres with the higher power modules.
Edited by - Dr_Acula on 21/08/2007 14:40:16