Parallax 433 MHz RF Transceiver Package
choco
Posts: 3
Hi, I just saw this new product.
http://www.parallax.com/detail.asp?product_id=28180
I'm planning to get one of this package. but I'm going to use it with other microcontroller (BasicATom 28)
I'm just wondering if anyone here can help me with the sync pulse
why 300? why 1200?
From the pdf (http://www.parallax.com/dl/docs/prod/rf/27980-ParallaxRFTransmit-v1.0.pdf)
For BS1s the following code line sends an appropriate sync pulse:
PULSOUT 1, 300 <--- from where did this come from?
√ For BS2s the following code line sends an appropriate sync pulse:
PULSOUT 8, 1200 <--- also this one
√ For Javelin Stamp modules the following code line sends an appropriate sync pulse:
CPU.pulseOut(300, CPU.pin8);
(Note: this line assumes that I/O pin 8 is connected to the DATA line on the transmitter)
so sorry my english is not very good
May be this is the correct question
How to get the number?
What value should I use for my BasicAtom 28?
Last time I bought 2 surelinks but I think I screwed it up and now I need a replacement but short of money.
then I saw this transceiver package, good value and don't need a lot of wiring so I won't screw it again
Please... Please help me.
Anyone?
http://www.parallax.com/detail.asp?product_id=28180
I'm planning to get one of this package. but I'm going to use it with other microcontroller (BasicATom 28)
I'm just wondering if anyone here can help me with the sync pulse
why 300? why 1200?
From the pdf (http://www.parallax.com/dl/docs/prod/rf/27980-ParallaxRFTransmit-v1.0.pdf)
For BS1s the following code line sends an appropriate sync pulse:
PULSOUT 1, 300 <--- from where did this come from?
√ For BS2s the following code line sends an appropriate sync pulse:
PULSOUT 8, 1200 <--- also this one
√ For Javelin Stamp modules the following code line sends an appropriate sync pulse:
CPU.pulseOut(300, CPU.pin8);
(Note: this line assumes that I/O pin 8 is connected to the DATA line on the transmitter)
so sorry my english is not very good
May be this is the correct question
How to get the number?
What value should I use for my BasicAtom 28?
Last time I bought 2 surelinks but I think I screwed it up and now I need a replacement but short of money.
then I saw this transceiver package, good value and don't need a lot of wiring so I won't screw it again
Please... Please help me.
Anyone?
Comments
On the BS1 the minimum pulse width is 10uS andmultiplied with 300 makes it about 3mS.
On the BS2 the minimum pulse width is 2mS and multiplied with 1200 it makes for 2.4mS.
As for what to use on the BasicAtom, I suggest reading your manual, or ask in the appropriate support forum.
(I don't have a manual for it, and don't intend to download it even if it should be available)
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Don't visit my new website...
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Chris Savage
Parallax Tech Support
csavage@parallax.com
Chris:
I'm going to use BS2 on PC side and BasicAtom 28 on Robot side (it requires faster CPU and more memory).
Now the problem is how to get them to talk to each other.
Gadgetman:
So sorry but I think you get the wrong idea.
What I was trying to say is why the bs1 have to use 3 ms and bs2 have to use 2.4 ms and what value do I have to use for my BasicAtom just to get it synchronize with BS2?
Is it the same as the BS2? 2.4 ms?
Ok... This might be inappropriate to ask in this forum. It's just that I have a little problem with english.
From the BasicAtom manual:
PULSOUT will generate a pulse with a period in 1 μs increments. The minimum pulse width is 4 μs. You can not go below this value. On BasicAtom 28 the minimum pulse width is 4us.
Example
PULSOUT P0,1000
;Generate a pulse for 1 millisecond long to P0
does this mean, the the minimum pulse width for BasicATom is 1us and time cannot go below 4us?
if 2.4ms is used then it should be "PULSOUT P1, 2400" ?
am I right?
Once again, please help me
(Don't expect the 2us or 10uS timings to be perfect. Xtals may drift, they may be influenced by heat or cold, anything... )
In other words, try with a pulsout of say 2.5mS and if that doesn't work, change it up or down until it works.
What kind of robot are you building?
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Don't visit my new website...
Ok, I'm going to order it from my local distributor.
btw I still need someone from parallax to confirm the pulsout duration.
Ok, now to answer your question.
I'm building a humanoid robot with 27 dof. similar with open pino but with an additional dof on the torso.
The robot will have two modes: remote controlled and autonomous.
The robot is using a servo controller, a cmucam,a memsic and a ping sensor and wireless module to control the robot.
I've done with the construction but still need to tidy up all the cable.
I'm having trouble interfacing the memsic (don't know how to get the tilt angle using BasicAtom). I tried to translate BS2 code to BasicAtom but I'm getting a weird number.
Ping already work.
Haven't done much with the cmucam.
coding in BasicAtom is really confusing.
BS2 is much easier and there are more codes that you can borrow and use.
Your math is right but your transcription is wrong BS2 minimum pulse width is 2uS not 2mS.
As for other comments here. The fact is that the only consideration for the hardware hosting the transceivers is whether or not the hardware supports some semblance of a PULSOUT command (and of courser serial output). It matters not one bit whether its generated on a BS1, BS2x, or Basic Atom, SX28, SX48 ...
I literally just received a set of transcievers and I think by way of familiarizing myself with them I will code up a set of excercises to vary the sync pulse width and see what happens. As they say, "film at 11"
Rasically its purpose is to wake up the reciever to the fact that a data frame is imminent. I haven't seen any real heavy duty data sheet on these units, I suspect its not unlike the 20 or thirty 'flags' sent at the front of an HDLC frame. Like the bandleaders saying "a 1, a 2, a 1, 2, 3, so everyone is in sync.
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cheers ... brian riley, n1bq, underhill center, vermont