View Full Version : Jan. 2010; Nuts & Volts: The Spin Zone - SIRCS, Propeller Style!
The newest The Spin Zone·article for the January 2010 release of Nuts & Volts·magazine·is available for download on our Nuts & Volts articles page:
Or, you can download them directly:
Column (.pdf)·- http://www.parallax.com/Portals/0/Downloads/docs/cols/nv/prop/col/nvp4.pdf
Code (.zip)·- http://www.parallax.com/Portals/0/Downloads/docs/cols/nv/prop/code/nvp4.zip
Oooooooh, check 'em out, check 'em out, check 'em out!
Okay, I have to ask: Is "Bump" a real name or is this the generic marketing account?
Powered by enthusiasm
12-15-2009, 03:35 AM
" The entire frame is transmitted within a 45ms window. Most remotes will repeat the SIRCS code at least three times to ensure it has been received..."
A few notes:
1- Devices actually receives twice the code, if the two are equal execute the action. The reason is that the Sony system does not have error checking.
2- Old devices are usually sensitive to time.
The correct (it works for all): Send frame, wait 45 ms (42ms I use in my code), send the same frame.
In many new devices, you can send the frame, and when you want you can send the other.
I have corrected a small mistake, the frame is 45ms,not necessary to wait longer to send the second.
I perform in my code pause (42ms), but for the Cog fully perform their work and to synchronize the final bit/end/stop.
Post Edited (Luis Digital) : 12/15/2009 12:19:30 AM GMT
12-15-2009, 03:42 AM
Bump is my little brother!
And totally real.
12-15-2009, 03:44 AM
Why the demoboard was used in the example as opposed to the unit we built (a couple issues ago)
for the article?
New to the Propeller?
Visit the: The Propeller Pages (http://www.warrantyvoid.us/tiki-index.php?page=Propeller) @ Warranty Void.
12-15-2009, 05:40 AM
@OBC: Yes, you've probably got all the parts you need (IR LED, IR Demodulator, a couple resistors) -- plug them into your Demo Board and rock-n-roll.
@Luis: The information I have suggests that a frame is 45ms and they can be sent back-to-back, especially since the worst-case possible timing for a 20-bit SIRCS code is less than 39ms, leaving 6ms for processing. I have many Sony remotes and have looked their outputs on a 'scope -- all send the frames back-to-back. I'm not saying that you're wrong, I just haven't seen it in my practical experince nor in any technical information that I could find. If you can point me to that, I'll happily update the driver to allow for a break between codes when multiples are transmitted.
On your point about codes twice, I have a couple Sony camera remotes that transmit each button press 5x! TV remotes I've worked with tend to be 3x. This is why I wrote the TX driver such that you can select the number of repeats for the code. I suppose I could rewrite the RX driver such that it has to RX the same code twice before passing on to the hub. Maybe another day... I've worked with that code style in both the SX and the Propeller without any problems. Of course, you have access to the source code so you could show me how! ;)
Happy Holidays, everyone!
12-15-2009, 05:51 AM
He has a real name, but he's known only by his baby name at Parallax: Bump. Only a few people inside Parallax know his real name, and you can call him Bump too. It's not an offensive name from his standpoint. Feel free to mess with him·because he can handle it, though his bigger sister protects him from time to time.
A real NorCal "Yo Bro" to you, and welcome to the forums! Nice to see you here with good information for the Propeller crowd. Don't be shy, and keep those webdev efforts rollin' with hot information for the Propeller heads! They won't know about your secret stash of Propeller resources unless you tell them - welcome!
Post Edited (Ken Gracey (Parallax)) : 12/14/2009 10:56:34 PM GMT
12-15-2009, 06:45 AM
@Luis: The information I have suggests that a frame is 45ms and they can be sent back-to-back,
That's right, I am wrong, or rather confused with my own code. http://forums.parallax.com/images/smilies/smile.gif
Yes I have experienced in modern devices that after the first frame I made pause for a minute (hours? Not know), and send the second, then the device performs the action.
On your point about codes twice, I have a couple Sony camera remotes that transmit each button press 5x! TV remotes I've worked with tend to be 3x.
Much transmitters send while you have the button pressed.
Commands = frames transmitted / 2
The device can also ignore unnecessary or repeated commands.
This is why I wrote the TX driver such that you can select the number of repeats for the code. I suppose I could rewrite the RX driver such that it has to RX the same code twice before passing on to the hub. Maybe another day... I've worked with that code style in both the SX and the Propeller without any problems. Of course, you have access to the source code so you could show me how! ;)
Receive twice is correct, for error checking, but for our purposes is not very important.
But to TX is required to send the frame twice, if you want to make a commercial transmitter.
Happy Holidays, everyone!
Happy Christmas and New Year to you too, and all the world. Unfortunate the Propeller 2 not be with us celebrating. http://forums.parallax.com/images/smilies/smile.gif