CC1101/2500

Hello Sam,

I am glad to be able to help you.

1.  The CC1101 chip is a leadless QFN component.  These are soldered by using a "reflow" process where solder paste is applied to a bare board and the component is then set into this paste.  After all the other components are likewise set into place, the whole board is subjected to a heating process that melts the solder.  Though not impossible, it is extremely difficult to solder these chips by hand.

2.  SPI is a serial interface that is commonly included in modern microcontroller chips.  For example, I use a Microchip 18F4550, which includes SPI.

3.  The exposed die attach pad is the square pad on the bottom of the chip.  This is a ground pad that gets soldered to the board during the reflow process.  

For you to get started with this stuff, you would be best served to purchase a demonstration board.  You will find a number of these available as you search the web.  I never purchased a demo board, I started out with the reference design and laid out my own boards using the Johansen balun to reduce component count.  I got lucky, and it works.  I had to learn the reflow process as I quickly discovered how difficult it is to solder these devices by hand - even under a microscope.  I use a hot air pencil to do my reflow.  Here's a great site with some videos: http://www.zeph.com/papers.html

Enjoy!

Dan

Hi Dan,

Many thanks for your kind support.

Unfortunately i'm really slim on my budget and cannot purchase an eval board. Is there a way to substitute the CC1101 with another chip that would allow me to actually solder and build an eval board. Maybe I'm missing something - is the reflow process an expensive affair?

I want to first test my system to ensure it works fine. Hence the resistance to spend freely. (It's been a long time since I've soldered a chip or even put together a schematic on EAGLE !)

Incidentally a brief about my project. Me n my wife love cycling and want to be able to talk while biking. You would be able to figure out the rest ! :)

best,
Sam

Sam -

in addition to Dan's great comments, CC1101 is QFN, and is not very difficult to solder if you have the right equipment and a steady hand. The key is to tin one pad (i use corner pad on PCB) then line up QFN over the pads (looking through microscope) and look at at least two sides from side angle with a spare microscope eyepiece while holding it on the board in place. Then using correct size soldering iron tip (i use Metcal tip for QFN size ==> http://www.metcal.com/products/cartridges/#c2), you can solder the corner pin/pad, then have a look again from side angle to make sure you are still lined up. if you have moved any, you can adjust slightly to get back on the pads correctly, then solder opposite corner pad. Now you should have stable connection and you can go around the IC and connect the rest of the pins. I also use some flux from time to time, depending on solder type being used.

I would also then recommend using MSP430 for driving the CC11xx parts as both are TI devices and so then this would be proper device to use here as this is after all a TI forum. Be glad to help you out further with this as well. It is not a task for the impatient, so take your time as you first start out here with this size technology.

Hi Sam,

Are you looking to build a system to transmit continuous audio?  I have no idea if the CC1101 is able to handle something like this.  I'm using it to just send single packets every few seconds.  

If you haven't done any soldering recently, I would not recommend trying to solder these chips.  

Dan

Hi Josh and Dan,

Thanks for your patience and great support. I found someone here in my city who can do the soldering on the PCB (Using the reflow process).

Now I'm sensing that I'll have trouble building the layout for the PCB as the software I intend to use (EAGLE was what I used in college) may not cater to the real estate of the particular chip. Is there any free software that I could use for building the PCB Layout while considering these QFN chips?

Dan,

To answer your question - I was actually looking to do a PTT kinda system. However I'll need to create another switch near the bike handlebar that the rider will have to press ON to be able to transmit. From my point of view this looks a tad more complicated and hence I decided to do direct streaming. Now that you mention - I had actually narrowed down to the CC2500 for this continuous 2 way broadcast. But again - I might not have done my homework well enough. :(

There are a few companies that make these kind of things for bikers. The main transreceiver box gets fitted on the bike and the broadcast switch is on the handlebar.

Once i can establish the wireless link between the 2 sets - I'll explore the option of a voice activated PTT switch. Basically the first syllable from the broadcaster (individual) will activate the WOR. I'm not sure if the WOR can start in milliseconds - but that is for later.

best,
Sam

Sam -

Sure, actually I / we / alot of us her at TI also use Eagle as well as other programs. Eagle supports QFN and if you go to cadsoftusa.com, they have *.lbr files you can search through. In your case, the CC2500 is a 20 pin PVQFN...if you go to this link, you will find Eagle design files (which include schematic and layout) for the ez430-RF2500 target board. Might save you a bit of time here. :)

http://www.ti.com/litv/zip/slac255

Hey Josh,

Thanks - I'll check this out.

best,
Sam

Hello McFarland

I need the  CC1101 SPI  library for PIC 24F in C. Where I can find?

You've created your own library??

You can pass me?? to have as a reference.