Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: allahjane on September 19, 2012, 09:18:01 AM
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Hey I got this RF transmitter and receiver pair from ebay (Says 434Mhz and ASK modulation)
http://www.ebay.in/itm/280952855034?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_1883wt_1139
(http://www.ebay.in/itm/280952855034?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_1883wt_1139)
Its same as
https://www.sparkfun.com/products/8950 (https://www.sparkfun.com/products/8950)
I prepared a test circuit on a Breadboard/project board as shown in the Attached Image
on turning on the power the Data Pin on the receiver side Always remains HIGH (+5v) no matter what
Even when the transmitter is removed from the circuit the receiver give HIGH output at data pin
I'm using the digital data pin and the ground pin to form the data out circuit as you can see in the figure labeld as data terminals
However a the data pin on receiver goes to LOW state for a split second whenever i give a +5v to the data pin of the transmitter i.e closing the D switch (this may be due to the fact that I'm using the same power Source for both transmitter & Receiver) after then it quickly becomes HIGH again
there is no tuning controls available on the pair either
What am i doing wrong? has the ASK modulation has to do something?
Please help me
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What is the voltage on the data input pin when nothing is connected?
Try putting a 1k ohm resistor from the data input pin to +5V and see what happens when you then ground the pin...at least I would try that.
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Hi,
Hey I got this RF transmitter and receiver pair from ebay (Says 434Mhz and ASK modulation)
http://www.ebay.in/itm/280952855034?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_1883wt_1139
(http://www.ebay.in/itm/280952855034?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_1883wt_1139)
Its same as
https://www.sparkfun.com/products/8950 (https://www.sparkfun.com/products/8950)
I prepared a test circuit on a Breadboard/project board as shown in the Attached Image
First off, connect it as in the datasheet - and connect all the pins!
on turning on the power the Data Pin on the receiver side Always remains HIGH (+5v) no matter what
[...]
However a the data pin on receiver goes to LOW state for a split second whenever i give a +5v to the data pin of the transmitter i.e closing the D switch
These two statements are mutually exclusive ;)
How do you verify the output low situation?
Even when the transmitter is removed from the circuit the receiver give HIGH output at data pin
How do you verify that it's high?
'Scope , voltmeter or what?
I'd guess it received noise, but you need a scope to see that.
What am i doing wrong? has the ASK modulation has to do something?
As mentioned, you didn't connect it up fully, so please test that and post back the results.
The ASK modulation is nothing you should worry about - it's an internal thing - you'll just "see" the plain logic signals.