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Topic: Cheap UHF spectrum analyzer (and RC tx rx) using RFM22 module (Read 52991 times) previous topic - next topic

florinc


zitron


Nice little board. How much are they?


Probably £2-3 each depending on whether you want them coloured, and thickness.

Devonian

Hi Zitron,

I'll take one of your new boards as it'll just about shoehorn into the Futaba T9C module cavity.
PayPal OK?
I have enough components to build onto the board.
Real shame you couldn't get it to fit inside a Futaba Tx module case ;)

Nigel.

zitron


Hi Zitron,

I'll take one of your new boards as it'll just about shoehorn into the Futaba T9C module cavity.
PayPal OK?
I have enough components to build onto the board.
Real shame you couldn't get it to fit inside a Futaba Tx module case ;)

Nigel.


Have you got the inside dimesions of the Futaba module? Is it the same as the 9X ones? I haven't sent the files to be manufactured yet so it is possible for me to change the designs and make it even smaller.

I can also try to make a tx only version, which will be much smaller.

Devonian

#94
Jul 03, 2012, 12:31 am Last Edit: Jul 03, 2012, 09:25 am by Devonian Reason: 1
Futaba Tx module:
http://www.hobbystores.co.uk/default.asp?itemid=Y-MA2214

A Tx only board would be great, but it would need to fit inside the module case to make it 'nice'.

I haven't built a Tx as yet, but will mash something together to try out on one of the boards I have from you.

I'll get you some dimensions from my Flytron board/module...

At a guess, the width will need to be around 33mm and the length is around 55mm.

EDIT

How about a Tx board that would fit inside the width of a Futaba case, and fit inside a JR module case as well (by making the length of the PCB fit the width of the JR case as they are wider than a Futaba case)?

JR case
http://www.jrradios.com/Products/Default.aspx?ProdID=JRPA615

Could be do-able by using coax for the antenna and short ribbon 'jumper' cable for Tx inputs?

Just a thought...

/EDIT

Nigel.

Devonian

Well, I went ahead and got a couple of the Futaba Tx module cases.

The internal dimensions are:
Width 34mm & length 54mm

Zitron, If you are willing to make a PCB that will fit the case, I can send you one of my spare cases as a pattern.
A Tx only board could then be made to fit a Futaba, a JR or just a 'hack module board' for 9X etc.
As I said before, I'm happy to assist with board costs.
An SMD mount Atmega would make the board size a doddle, albeit more difficult to solder (not a problem for me as I have an SMD hot air solder station) ;)

This is the kind of thing I'd like...
http://blog.ckdevices.com/?p=119

What do you think Zitron?

Nigel.

zitron

I think I can do 50x34 with the 28 DIP package. If I make a board 34mm wide, will it fit? Or should I make it 33mm just to be safe? If it needs to be much smaller I will have to go SMD.

I will need to redesign the board completely though. I pretty sure I need to add a 5V regulator as well. It might take a while...

Also you probably will have to drill holes and what not in your case to mount the connectors, LEDs and switch externally.


zitron

Wait are you sure you measured the Futaba modules?

I have a 9X which I think uses JR modules, but also measures 54x34??

Ngakuta

I would really like to build your Spectrum Analyser. Could you please tell me where to find the component layout etc of your board. I see a comment in this forum that the schematic is "attached", but i cant see where it is attached. Sorry to be so stupid. You also offered to send a copy of the board to someone. I would really appreciate this. My email is Ngakuta1@xtra.co.nz Thanks a lot.

zitron


I would really like to build your Spectrum Analyser. Could you please tell me where to find the component layout etc of your board. I see a comment in this forum that the schematic is "attached", but i cant see where it is attached. Sorry to be so stupid. You also offered to send a copy of the board to someone. I would really appreciate this. My email is Ngakuta1@xtra.co.nz Thanks a lot.


Unfortunately I don't have any boards left right now. I will let you know I I get the new ones back from China.

You should be able to see the attached files now that you've joined the forum!

Devonian


Wait are you sure you measured the Futaba modules?

I have a 9X which I think uses JR modules, but also measures 54x34??


Just re-checked and the absolute maximum space inside the Futaba module case is 34mm wide and 53mm length.
I can just get an Arduino Pro Mini board inside the case, positioned with the length of the Pro Mini across the case, so giving ~34mm of available space inside the case.
5v version
http://proto-pic.co.uk/arduino-pro-mini-328-5v-16mhz-new/
or
3v3 version
http://proto-pic.co.uk/arduino-pro-mini-328-3-3v-8mhz-new/

Maybe I'll hack a Pro Mini and RFM22B onto a bit of Vero board and see what happens...

Nigel.

zitron

Huh so futaba and JR use the same size boards...

A 50x33mm board is definitely doable with through hole 328, I can start working on it if you still want one. We can split the cost of ~£20 for 10 boards.

Which pro mini do you have? If you have the 5V version you will need to use a 3.3V reg for the RF22, and some resistors to divide the arduino SPI output to 3.3V. It could be quite simple if you have the 3.3V version, but I am not sure if my code will work at 8MHz.

Devonian

I have a 5v Pro Mini that I used on an early WiiCopter - still have a couple of Jussi's PCB's if you want one FOC?

I'm happy to split board costs with you for something that will fit both Futaba and JR.

Look at the case photo I posted a couple of posts back, it would be great if the board would fit and be able to connect the Tx pins into the board.
It will need a 5v reg as the Futaba Tx has battery supply voltage on one of the pins.
I can send you a spare Futaba case for testing.

Flytron makes a JR to Futaba adapter board for the Tx
http://www.flytron.com/123-futaba-jr-module-adapter.html

Perhaps we can continue this by PM and personal email exchange?

Nigel.

Nandox7

A Futaba module would be perfect. (I have a 9C) :)
If needed I can measure the module box.

The only thing is that the module has a odd pin spacing for the connector.


Btw one cool thing would be to have a smaller RX pcb, will less pins to be able to easily fit into a plane, quad,...


zitron

If you can confirm that a 50x33mm board will fit inside your Futaba module it will be great.

I think you will have to solder your own connectors, because I'm pretty sure JR and Futaba pins are different.

I may look into smaller SMD versions if there people are interesed.

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