Have a question about radio or wireless communication?  Ask me!

I want to build a system which monitors water flow from pipeline and   detects the clogging if any

so i need to embedded a sensor, a microcontroller and a RF module  together..please help  me out to find  a suitable rf module

regards

Hello Chris,

i have a small question that is it possible to convert radio and micro waves coming to our mobile during a call to be converted in to electricity,i am working on that please suggest me appropriate way

I want to know that is there any way to impelement the concept of cognitive radio practically, if yes then  how much will it cost ?

Hello Chris

Is is possible to create a wireless network in an embedded system based on say an arduino shield or microchips TCP/IP stack, and have a mobile or android app connect to that network in a automation system?

I have made a wireless application using microchip miwi. I want to link to wifi to get the data to the internet. Have you seen any examples of this linkage? Microchip has little or no documentation on this. Is there a better approach? 

Hi, I'm working on a location-based system which trilaterates wifi signals.  Currently, mobile assets are tracked using off-the-shelf battery-powered wifi modules. 

No real wifi communication is needed between the tag/AP other than measuring the tag RSS on the AP side. 

I'm looking for information on what it'd take to build a stripped-down, bare mimimun, "fake" wifi node whose only job would be to transmit a hard-coded probe frame? 

what would be the minimum hardware to transmit that hard-coded frame?  Any cost/pro/con comparison with off-the-shelf full-wifi solution?

I'd appreciate any info/pointer.

Thank you

It depends on your detector.

10KHz is just about the lowest frequency anyone ever calls "radio frequency." (Yes, some Navys use far lower frequencies, even in the single digits, for underwater, around the world, submarine communications, but that is rather, um, "special."

But 10KHz is also within the range of human hearing. That begs the question...

What method are you using to create and detect these frequencies? If you create it with an audio transducer ("a speaker" (a fairly small one)), then you are creating a mechanical wave ("a sound wave" in this case) which will travel at roughly 340 m/s in air (dependent on temperature, etc.) and you will detect it with something like a microphone. On the other hand, if you are creating your wave with an antenna then you will be creating a electromagnetic wave which will travel at 3x10^8 m/s and you will receive it with another antenna (another very long one).

The general equation relating speed of a wave and wavelength is lambda = v / f. This is altered slightly into the form you provided, lambda = c / f for the special case of electromagnetic radiation (radio waves, microwaves, light, x-rays, gamma rays). In this case c (speed of light = 3x10^8 m/s) replaces the more general "v." But when dealing with mechanical waves, for example, sound, you set v equal to the speed of sound in the medium being analyzed. Note that speed of sound in air and water are much different.

I need to send 10-bit data from the Analog to digital converter(ADC) from a dsPIC at 2Mbps through UART interface, to a bluetooth module. Then the bluetooth module should read this data through its UART

interface and transmit this data via bluetooth which will be finally received by an Android phone. An application in the phone will take this data and plot a waveform on the screen.

So basically the phone will recieve data at 2 Mbps via bluetooth. Is this practically possible ?

Most bluetooth modules say they can transfer data only around 300 kbps using RFCOMM protocol. Is there any reason for this ? It says to go upto 2Mbps it is needed to use the HCI protocol whch needs to be implementedon the host processor. So then can the Android phone read data sent in HCI protocol. Is there any support available. Currently all transfers done in Android which I found are in RFCOMM. Is there any way either using RFCOMM or any other means for Android phone to aquire atleast 1.5 Mbps data via bluetooth ?

What bluetooth module would you suggest is best for this application ?

Thank you,

Best Regards.

Hello I'm planning a HAB and for that I choose the RADIOMETRIX  NTX2-434.650-10NTX2-434.650-10 TRANSMITTER 434.65MHZ 10MW

the balloon wil be 30 km from earth and sending messages RTTY to my ICOM-IC R20 in ssb mode 70cm. but I dont know what antenna to use for the balloon, neither for the ICOM IC-R20.

Can you please help me?

Thanks, Daniel

Hi Chris I did post this as a general question but with your experince I would greatly appreciate some advice if you can spare the time!

Im about to embark on electronics/comms/telecomms training. After that I want to specialise into something?

Im looking at Scada/control systems, wireless comms and RF.

While I have a background in programming and some physics the technical aspects/terminology are daunting as all these fields offer a myriad of avenues. Im good at understanding requirements, working with people up to board level and making things happen/solving problems

My question is this:

1. Im looking for the most mobile skill( I love travelling and wayout places ) and obviously well paid

2. Where is the convergence going in these fields, so I can position myself correctly?

3. It seems to me that Scada guys need a lot more training/diploma/degree and experience versus the RF/radio technician guys? Why do radio techs earn so much? How do you become a radio tech?

4. I have family in Australia, my brother is an engineer there, and there are diploma courses that cover the basics of these technologies and have some elective choices. Is it possible to do more specialised training straight off(eg Motorola) if I can teach myself the physics etc?

Im in South Africa and there is no specialised training here except for people who are already in the industry, so im looking abroad for training. Im in my 30's so Im not looking to go do a 3 year degree in Electronics, Id rather work and learn after studying for say a year, is this realistic or possible?

Any advice, help, referals to other forums are very much appreciated!!

Jano