I've recently purchased a 433Mhz Transmitter and receiver for use with some arduino unos. The transmitter has 3 connections, ground, vcc and data, simple enough! Having read a bunch of examples on the Internet it seems that for best results it should be powered using a high voltage, I.e. powering it using the Arduinos 5 volt pin is preferable to the 3.3 volt pin.
So when I connect the transmitter to my arduino using the 5v pin the arduino seems to just shut down, all the lights go off and it appears to be dead. If I use the 3.3 volt pin it works and I can run code on the arduino. I've got code running using the 3.3 volt pin but the data im transmitting isn't working. Not sure why this is yet but I'm concerned that it's because I'm underpowering the transmitter and don't understand why I cant power it with the 5 volt pin.
So my question is this, why would using the 5 volt pin to power my transmitter cause my arduino to not work yet the 3.3 volt pin seems to work fine?
Thanks a lot for the comments. The spec sheet says the transmitter takes between 3.5 and 12 volts, I think that's seems to be pretty standard for these type of devices. This is why I think at 3.3 im under powering it.
I'm pretty sure I have it wired correctly, not much to go wrong really. Ground to ground, vcc to 5 volt pin and data to a digital pin. I've tried it on 2 Arduinos and it's the same on both... Could the transmitter be faulty?
No I haven't checked the 5 volt pin, I try that in the morning. I did try it on 2 different Arduinos in an attempt to rule out the arduino as the faulty component, but your right, best to check.
I'm fairly new to this stuff so im expecting to spot some ridiculous mistake I made! It's just so odd, and im fairly sure Ive got set up right. As the transmitters are so cheap, I might try buying another to see if that works.
ChilliTronix:
Well in that picture you have the VCC connected to 3.3 V.
Does it transmit at all powered by 3.3 V?
Also check the voltage provided by the 5V line.
Yeah chilli, that's the wiring config that allows the arduino to power up normally. If I move the to red wire to the 5v pin and power up, the arduino just appears to be dead, no lights no nothing....
I'll test the 5v pin, perhaps could try powering the transmitter for another power source, perhaps a 9v battery?
Ok, I've finally tracked down my multimeter after my wife kindly put it away for me in a very safe place! I've confirmed that the the 5volt pin does indeed provide 5 volts so it's seems the arduino is fine.
Also, using the 3.3 volt pin I manage to get the thing to transmit something but it was almost random. I know it was doing something as when I remove the power to the transmitter, the signal the receiver was getting stopped.
Gonna check the regulator next Genesis. Just got to google to find where it is on the board! One second....
Genesis92:
and about my question? the regulator is hot or not? -> if yes your module seems to create short circuit
Ouch! When the transmitter is plugged into 5volts the chip in the center of the attached image that is vertically aligned gets hot quick. So does that solve the problem, the transmitter is faulty?
Thanks again for all the help, I was a little worried about using the forums being new to all this stuff but u lot are great!
like explained in my post, if the regulator is hot -> short circuit -> faulty emitter
you can try to post the top/bottom of the emitter PCB, it's perhaps a solder ball somewhere.
As a general rule, RF transmitters require a load (antenna) connected when powering up.
This is why all WIFI Access Point and Repeaters have warning labels to connect the antenna before connecting power. That Tx uses a 20 cm long coiled wire soldered to the antenna pin pad, (the labeled "ANT"). The receiver uses a 17 cm long STRAIGHT antenna. Both are constructed using 20 guage hookup
solid hookup wire. That being the case, I have used that transmitter many times before I learned about
the antenna you should add and it never blew the output transistor. My guess is that it was miswired the
very first time and that's when it was blown.
Just wanted to let everyone know that I purchased a new transmitter and receiver which works fine. I guess this confirms that my initial transmitter was faulty and also that im not losing my marbles
