 |
JP1 Remotes
|
| View previous topic :: View next topic |
| Author |
Message |
vickyg2003
Site Admin
Joined: 20 Mar 2004
Posts: 7073
Location: Florida
|
 Posted: Sat Sep 04, 2010 9:42 am Post subject: |
 |
|
I've been trying to explain RC-5 to jyll, and I'm having trouble interpreting the IRP.
Uploaded with ImageShack.us
~F:1:6
I always have a lot of trouble interpretting the multiple colons ::: in IRP, so I took a picture of the signal to see what was what.
I thought that ~F:1:6 meant the complement of bit 1 of the function expressed in 6 bits,
but that doesn't agree with what is being sent. So then I thought that meant the complement of bit 6 of the function expressed in 1 bit, but that doesn't seem to be correct either since that bit is 1 and bit 6 of the function is 1 so that's not a complement.
Can someone explain colons in IRP to me once again, so that I can correct my explanation in the protocol primer.
_________________
Remember to provide feedback to let us know how the problem was solved and share your upgrades.
Tip: When creating an upgrade, always include ALL functions from the oem remote, even if you never plan on assigning them to a button. Complete function lists makes an upgrade more helpful to others.
|
|
| Back to top |
|
 |
cauer29
Joined: 03 Feb 2010
Posts: 236
|
| Posted: Sat Sep 04, 2010 11:13 am Post subject: |
|
|
| vickyg2003 wrote: | I've been trying to explain RC-5 to jyll, and I'm having trouble interpreting the IRP.
Uploaded with ImageShack.us
~F:1:6
I always have a lot of trouble interpretting the multiple colons ::: in IRP, so I took a picture of the signal to see what was what.
I thought that ~F:1:6 meant the complement of bit 1 of the function expressed in 6 bits,
but that doesn't agree with what is being sent. So then I thought that meant the complement of bit 6 of the function expressed in 1 bit, but that doesn't seem to be correct either since that bit is 1 and bit 6 of the function is 1 so that's not a complement.
Can someone explain colons in IRP to me once again, so that I can correct my explanation in the protocol primer. |
As far as I can tell, ~F:1:6 means that this field is 1 bit long and it's the complement of bit 6 of the function code. Remember though, that bit 6 is the 7th bit, since we start counting at 0. So for OBCs less than 64 this bit will always be a "1" and for OBCs 64 or greater this bit will always be a "0".
A.A. |
|
| Back to top |
|
|
jyll
Joined: 09 Aug 2010
Posts: 25
|
| Posted: Sat Sep 04, 2010 11:31 am Post subject: |
|
|
From Wikipedia's RC-5 protocol page:
| Quote: | | A field bit, which denotes whether the command sent is in the lower field (logic 1 = 0 to 63 decimal) or the upper field (logic 0 = 64 to 127 decimal). The field bit was added later by Philips when it was realized that 64 commands per device were insufficient. Previously, the field bit was combined with the start bit. Many devices still use this original system. |
From SB-Projects' RC-5 protocol page:
| Quote: | | Extended RC-5 uses only one start bit. Bit S2 is transformed to command bit 6, providing for a total of 7 command bits. The value of S2 must be inverted to get the 7th command bit though! |
RC-5: Start 1 / Start 2 / Toggle / Device / OBC
RC-5x: Start / Field / Toggle / Device / OBC
110 00000 000001 (RC-5)
..6..............543210
110 00000 000001 (RC-5x Lower Field OBC 0-63)
..6..............543210
100 00000 000001 (RC-5x Upper Field OBC 64-127)
Last edited by jyll on Sat Sep 04, 2010 11:45 am; edited 2 times in total |
|
| Back to top |
|
|
vickyg2003
Site Admin
Joined: 20 Mar 2004
Posts: 7073
Location: Florida
|
| Posted: Sat Sep 04, 2010 11:42 am Post subject: |
|
|
| cauer29 wrote: |
Remember though, that bit 6 is the 7th bit, since we start counting at 0. So for OBCs less than 64 this bit will always be a "1" and for OBCs 64 or greater this bit will always be a "0".
|
Ah, starting at zero. and >64. I should have looked at remotemaster.
_________________
Remember to provide feedback to let us know how the problem was solved and share your upgrades.
Tip: When creating an upgrade, always include ALL functions from the oem remote, even if you never plan on assigning them to a button. Complete function lists makes an upgrade more helpful to others.
|
|
| Back to top |
|
|
johnsfine
Site Admin
Joined: 10 Aug 2003
Posts: 4766
Location: Bedford, MA
|
| Posted: Sat Sep 04, 2010 12:38 pm Post subject: |
|
|
| vickyg2003 wrote: |
~F:1:6
I always have a lot of trouble interpretting the multiple colons ::: in IRP |
I think you already understand. But just in case it is still confusing, I'l give you my point of view:
~F (as you already knew) is F with every 0 bit changed to 1 and every 1 bit changed to 0.
The value after the first : is the length of the field. That is true regardless of whether there is a second :. So this field is 1 bit long.
The value after the second : is the number of bits skipped to reach the field. This is always relative to the LSB end of the value, even in MSB signals.
So working from the LSB end, of ~F, we skip 6 bits and then select the next 1 bits.
The F:6 that is later in the same IRP, using those same interpretation rules means starting from the LSB end of F, we skip 0 bits and select the next 6 bits. Notice that those bits are selected relative to the LSB end of F regardless of whether this is an MSB or LSB signal. But after selecting them, we transmit them in MSB sequence because this is an MSB signal. |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
File Section
Wiki
