After many months of research in building lowest Bill Of Material (BOM) PCB that can must be power efficient and have maximum RF distance I think I have come to 2 designs that reach that goal.
- M1 is a generic flash "drive" that is controlled via SPI. I do not need it because CC2533 has some flash avaialbe but I can install anything from 4kb to 128mb/256mb/512mb if I need to store more data.
- This board will eventually take other expansions via the exposed pad on the bottom edge or communicate with it usin full UART to the right. The 3 pins next to 231 is a design request and will be implement propriety functionality.
- Bottom left is a nice thing suggested on a Stack Overflow- TC2030 - I will use it to burn my firmware and debug the system if needed.
All Texas Instruments remote's that use the CC25xx family chips use the F-Inverted on PCB antenna. I can only guess because it has a much better RF sensitivity with less errors. The folded dipole antenna is also suggested by Texas and does not need any balancing or tuning elements; so why don't they use it? My first rev board used folded dipole but I had very bad range and allot of missed packets. It turned out it was not designed properly (by somebody else) So I did it myself because I needed it doing properly!
When I burned my firmware to the Texas Development boards (using f-inverted on pcb) I got a fantastic range. Line of sight was about 20metres(0db gain) In my house from attic to ground floor (two floors and 3 walls) 100% signal no packet loss(0db gain) The CC2533 is capable of 6db gain if you need it :) Yes I tested 6db - I walked about 40 metres with 100% signal.(It uses allot of battery though)and 55metres before I had severe packet loss.
I am waiting for my tc-2030 then I can start testing these out. Can't wait :)