Radio Frequency Communication (RF)

[gg4rest]

I don't know if their indian language site works better, but none of their links on their english site work so I can't give you much information on that.

Are you creating a PCB? Wireless, from what I've heard, is difficult to make reliable for a hobbyist. Especially if it isn't on a PCB. I've had difficulty occassionally with a wired system and that should be relatively simple. The problem I think with wireless is, if you don't have a spectrum analyzer you can't really tell if your signal is being transmitted in an easy manner. I've done very little with RF so maybe someone else has a more informed opinion.

 

[chaitanya1]

hi you project idea is the best .but rf communication is some what difficult.
I have done worked on fm transmitter. it is to difficult. i suggest one easy way that the codeless phone of long range is available in market. so you can use transmiter and receiver part of that phone.

if you want other idea then my e mail id is [email protected]

 

[upneet]

No i was not hibernating these days! my project plans have changed drastically NOw i have to interface four sensors ph, temp ( lm35), light sensor ( from optical mouse or something) and humidity sensor if possible to a pic ( mostly pic 16f877) or similiar then i have to display this on led or lcd display and if this gets over then transmit it wireless and next stage is to receive this signal and interface with pc so that it can be displayed using java and VB.
extremely tough project i need all ur help
thanks

 

[upneet]

I am getting 4800bps data from my RF ic. Now i want to connect this to my computer I know i will have to use some ic like max 235 or something then i would like to use com port and some vb programming to get a good user interface which will show all the details about the sensed values with bit of graphics like graphs and all
can you please send me some information about it or any sites where i can get the codes and info
thanks u one and all

 

[Alun]

What does the IC output?

If its an RS232 type signal but a logic level you can buy a chip, here's the datasheet: http://www.datasheetcatalog.com/datasheets_pdf/M/A/X/2/MAX232.shtml

 

[MP1]

upneet,
All of the rf chips I have seen need a driver for RS232, so what Alun has suggested will work fine. MAX232 has become quite the standard. If you cannot find these dedicated chips in your area, you can make the same thing with a couple of common transistors and discretes.

In addition to the MAX232, the MAX233 is the same but does not need the added capacitors.
My favorite is the DS275 from Dallas Semi. This one is a very low consumption chip which uses some of the line voltage to power the chip. It is great for battery powered devices.

MP

 

[upneet]

Hi. Again the project has changed but now i am going to post lots and lots of details because my project demo date is nearing and i need lots and lots of help
now wer r using four sensors one pH sensor from sensorex, one local humidity sensor and two temperature sensors pt100 and lm35
we are interfacing this to atmel microcontroller 89c52 which is driving LCD.
we are getting digital output from this which we are transmiting using RF i am using ICs from www.mdclrf.com they are working fine.
at the receiver end we are giving this received signal to com port of pc using rs 232 and Max 232.
I want some VB code which can display this information.
I am uploading all the info that i have
thanks for help
prem.asm is the code that i have downloaded from the internet but its not working.
any idea how we can test that?

BD.zip

CODES.zip

 

[-Jack-]

Sorry but i have a queston.
I made a Walkie Talkie and find a paint of the circuit:
Who has a circuit?
Please send me the paint at [email protected]

 

[-Jack-]

BF184 is ugual to BF494?Please...