Help with TX RX Temp Unit Please

[acestu]

Thanks Enamul,

I will do a bit of research in the mean time...

Acestu

[Enamul]

No problem..Do some research while I am back.

[Enamul]

Hi

I have received the pair in hand..I will go for a try to-night

[acestu]

Hi Enamul,

I have just tried the 47k resister and nothing lit up, but the capacitor on the decoder is so small that i soldered it on to 2 pieces of wire, and when I went to pull it
out of the breadboard I must of shorted the wires out slightly and the LEDs started lighting up so I think I may have a capacitor problem.

thanks
Acestu

[Enamul]

Hi Stuart,
I have tried with 1M and 33K with both +5V supply and works absolutely fine for me. It seems resistor is not that much critical and that's why nobody in forums and datasheet didn't put any special note about this resistor value.

I am now going to test RF tx-rx pair with these ICs. Hopefully you are progressing in your R&D too.

[Enamul]

Hi Stuart,

I have just tested the Tx-Rx pair (similar to yours one) with the Encoder and Decoder. It works excellent. Now I am planning to test two Tx-Rx pair working at same frequency 433MHz but having different Rx decoder address. I want to see whether they interfere with each other or not. But my main plan is something else..to tag asset in room without using RFID.

The core idea is...I will use one master Tx-Rx with Microcontroller control module. It will look for slave control modules with Tx-Rx pair. Slave modules will be embedded in each asset. Master will look for each slave after a pre-defined time. If it can't find any slave in the network it will inform user that particular ID asset is missing.

The main obstacle is now working with multiple Tx-Rx but all using same carrier frequency. I will post that if I can get a satisfactory result.

[acestu]

Hi Enamul,

I am waiting for the resisters but I am going to build the circuits again tomorrow on 2 different breadboards, there are lots of different opinions on the resistors
and different schematics on the web, it is really weird because there is nothing to it really and I have done everything the same as per the diagram apart from resistor values...hopefully they will arrive soon.

thanks
Acestu

[Enamul]

But I have tried what I have posted first and it worked in a single go. 1M and 33K with 5V supply for both.

[acestu]

Hi Enamul,

Is there any chance that you could post a picture of your breadboard setup please, I might see something that I haven't done...

thanks
Acestu

[Enamul]

I will post mine one asap.

[Enamul]

Hi

I am not sure whether my pictures will help you or not..I have used EB006 for 5V power supply. 4 switches are used from EB007 and 4 Leds are used from EB004 and they are connected to EB016 proto-board (which is very handy to do this kind of test!). You will see encoder and decoder is in two different bread board. 1 to 9 pins for both the IC I put GND so as the address to be 0x00.

[acestu]

Hi Enamul,

Is there any way of testing the Encoder chip ?, at last then I could work out which board is not working....

Thanks
Acestu

[Enamul]

Hi stuart,
Do you have access to scope? As the frequency of data transmission is very high you can't find out without scope.

[acestu]

Hi Enamul,

No not yet , I hope to get one soon after christmas is over, there are some good pocket digital ones available on ebay, I thought that may be the case for testing data out...

thanks
Acestu

EDIT I have just tried a 1.1 MEG resister in the Encoder and a 51K resistor in the Decoder as per data sheets running both at 5 volts, but still dead as a dodo

[Enamul]

Hi stuart,

Have you seen that..that great piece of test equipment.
http://www.matrixmultimedia.com/product ... PHPSESSID=

[acestu]

Hi Enamul,

That looks like a nice piece of kit, good for analysing canbus too, I think I might be getting one of those...

I have found these also:

http://cpc.farnell.com/microchip/ht12e/ ... ?Ntt=HT12E

very cheap and in this country

Thanks
Acestu

[Enamul]

That's really good. Thanks for the link. I will order couple. Did you get the link for HT12D as well.

[acestu]

Yes they have both, just put it in the search pane in that link ok

Acestu

EDIT http://cpc.farnell.com/microchip/ht12d/ ... ?Ntt=HT12D

[acestu]

UPDATE


I have 3 pairs of chips being delivered this week 19/12 2012

thanks
Acestu

[Enamul]

Hi Stuart
Have you manged to get those working?

[acestu]

UPDATE:

Thursday now and no sign of the chips, I think they must of gotten caught up in the Christmas post, I am hoping that they will come tomorrow or Saturday.

thanks
Acestu

[acestu]

Hi Enamul,

I have just received my chips but unfortunately I have the same problem, can I ask you though my 2 boards are only connected with one wire the data line, should there be a common ground between boards ?

thanks
Acestu

[Enamul]

Ohhh..for the encoder and decoder circuit I have posted you must have to have common GND. When RF Tx and RX will be in place you will not need common GND but now we are using two digital IC simply which need common GND.

[acestu]

Hi Enamul,

Thanks for that I will try that when I get back home tomorrow...

thanks
Acstu

[acestu]

Hi Enamul,

I have connected a common GROUND and all the LEDs light up and when I push the buttons they go out, this is probably opposite now because I took out the pull up resistors...

thanks
Acestu