Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Ultra Low Cost FSK Demodulation on a Microcontroller

Status
Not open for further replies.

stuartiannaylor

Newbie level 5
Joined
Nov 8, 2006
Messages
10
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,375
Hi I am working on an open source hardware design and I am struggling.

The design utilises a SMPS Half Bridge 24Vac electronic transformer. The idea is to use the powerline as a communication network. This is fairly simple as the FSK carrier is represented by the switching frequency of the electronic transformer.

I am struggling to come up with a design that utilises as few components as possible on the receiver end. I am trying to use the lowest microcontroller possible without the need to go to 16bit DSP prices. Whilst also trying to keep the circuit foot print and complexity to a minimum.

The solution is to provide control for LED lighting modules and is aimed at the next generation of green lighting control. Mixing LED efficiencies with intelligent control.
The system emulates current electronic transformer technologies (yeah I know 12Vac) so that modern intelligent control can be employed without new training or wiring technologies.
I am creating a website to host the design and I am looking for people to contribute design idea's. The design is open source in a Ubuntu fashion but the creation of a low cost sub network with some common protocols could kickstart a major improvement in the LED market.

The design works with an electronic tranformer acting as a power supply and network bridge to a simple lighting control sub bus. As above I am looking at using FSK modulation to provide a low cost communication method. The system is a hybrid as it utilises a X10 style return signal to further remove circuit cost and complexity.

This will allow the electronic bridge to utilise WiFI / ZigBee high end protocols and minimise the cost as a singular unit connected to a string of power line controlled low tech sub bus lighting modules. This is much akin to CAN and LIN sub bus networks.

I am going round in circles in terms of the circuitry required for envelope detection, PLLs, Digital PLLs and the cost of a single chip DSP. I really would appreciate and idea's how to accomplish this as my juggling of passive component design's against single DSP versions has paralysed my design idea's.

Many Thanks
Stuart
 

sihuijian

Junior Member level 1
Joined
Jun 25, 2003
Messages
16
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
hangzhou,china
Activity points
119
Ti has a msp430 based fsk demodulator,
document number is : slaa037 and slaa204.
 

mircang9

Newbie level 3
Joined
Feb 20, 2010
Messages
3
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,301
I want to made a digital demodulator with PIC16F887 or PIC18F4455 microcontroller with its A/D converter. My FSK signal is: 2310 Hz for "0" logic and 2370 for "1" logic. A conversion during 7 us. A period for "0" logic is 210 us ( 30 conversion ), and a period for "1" logic is 216 us ( 30 conversion ) at 18 MHz runing microcontroller. Period i measure with Timer1. For two periods the difference between conversion is: 60 conversions for "0" logic and 63 conversions for "1" logic. Error recode the digital signal is +/- 1 ms. Can work this ?
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top