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Your formula is still valid the "c" in this instance should be subsituted for the speed of the wave in the medium you are working with.

So for say Radio in outer space then the 'c' would indeed be the clasical Speed of light in a vacuum  however if you are talking about the speed of a sound wave from say a train at sea level you need to obtain the speed of the wave in that circumstance which is indeed around the 340M/s

Hello Chris,

I wanted to adapt an xbox 360 controller to connect wirelessly to my PC. I know there is already a microsoft product that does this, but it has a long cord, the device is relatively big compared to other wireless devices (a wireless mouse, for example), and it takes multiple controllers. I was thinking of making it as small as possible and make it pair a single controller. It is not necessarily the best application; however, I wanted to experiment with wireless technology. In other words, I wanted to do the project for the fun of it. Which wireless technology do you advise me to use. If there is a better way of doing this, then how?

Thanks,

Jorge Rojas

Hi Chris,

Want to create a wireless- remote control switch for a 115v winch motor that will function over 500 ft, obstructed line-of-sight. The motor is currently controlled by a DPDT momentary switch to engage forward and reverse. A 800 ft, 4-wires cable is currently used to connect power to the motor and switch to control the motor. I want to create a wireless switch control (Tx/Rx) units to untether the winch motor from the truck. A portable generator will be used to provide power directly to the winch and the wireless receiver. I want to use once channel for forward and separate channel for reverse. Reverse is accomplished by a relay within the winch motor.   I'm thinking of something in the 27Mhz  or 433Mhz band, around 1W to achieve this distance.

I want to try and build this as a DIY project to learn about wireless controls.

It seems simple in the idea, but struggling with where to start... Tx/Rx components needed, relays, etc.

I have schematics for the motor wiring and the switch control box. Just want to replace the wire connecting them with a wireless connection.

I can send them to you if that would help.

Can you direct me some companies that can provide the components needed to build such a beast?

hi,

     I need your help regarding selection of a proper RF diode(smallest available as i hv to incorporate it in a ring) to light up 1  SMD 3525 leds.

Appreciate your time, thanks in advance

Pratap Singh

pratap12330@gmail.com

HIII SIR              

why we cannot transmitt the electicity wireless ....??????????

I have built a DIY variometer for RC sailplanes which uses arduino and inexpensive 433 MHZ transmitter and receiver.

The suggested TX is RF Solutions AM RT14, which is not available at element 14 or anywhere in USA. I have used the AM RT4

with moderate success but really need the more powerful RT14. Can you suggest an available substitute.

Thanks

On the following website you will find a description of a direction finding system. http://www.signal.uu.se/Publications/pdf/c0110.pdf The pattern of the antenna can be changed by steering the parasitic elements. This way the antenna pattern can be rotated electronically. The rotation speed could be between 12 Hz and 2 kHz. Don’t use a frequency that has any relationship with the mains frequency and don’t use a frequency outside the bandwidth of the receiver. The point of maximum signal can be compared with the actual position of the antenna pattern. This way the direction can be determined.  With two such systems at different locations you can find the position of the transmitter. The antennas could be located at the balconies on both sides of the building.

Dear Chris,

I am an electronics student with a project in mind and was wondering if you share some of your expertise on this.

The project consists of a pressing a button ( switch) and sending that signal (of the button being pressed) to a website and a phone app. The system consists of many buttons , so that when one is pressed the website receives a signal as to that button has been pressed.

My main problem is: How do I send that signal wirelessly over the air? Im thinking wifi, am i right? if so what hardward would I need.

Thank you Chris

Kind Regards,

Nikhil

Hello,

I have a question about wirelessly connecting two microcontrollers. I would like to create a custom hand-held controller for a a simple remotely operated rc car I am planning to make. I want a sending device to be able to read analog signals from my hand-held controller analog joysticks on several channels and have it be sent over wirelessly to the microcontroller on the car. I am aware that I can use IR, but I am unsure whether IR would allow me to send an analog signal so that I could, for example, change the speed of the motors. Also, I am unsure whether IR would be convenient since the led would have to be pointed directly at the IR sensor on the other end. On the other hand, I can use a hobby radio controller, but what I don't like is that it is very bulky and not very convenient for something so small. Radio is very convenient in the sense that you don't have to point it directly at what you're controlling in order for it to work and there is a large range. I also know that there is the Xbee, but those are relatively expensive. In my case, the cheaper, the better. Are there any boards that would let me have a radio transmitter with inputs from one microcontroller sending information to a receiver on another? What would be the best solution to this problem? Thanks for your time.

We are an R &D group ARGEBILISIM established in Turkey ,working for a new project for our company which consisits of collecting UART data from end devices stations using Jennic wireless technology .Here is Joined our network sheme , we are making our tests on JN 5148 module via AN 1061,  we would like to ask your advice as network- jennic- jennet professionals  :

-Does joined nodes end devices or routers should send automaticly their data to coordinator when they have data, is it  like CR already  scans its children joined automaticly one by one?  or  should we add in our program a scanning algorithm for reading one by one joined children if they have data so that all nodes don't send on same time their data to avoid loosing some of them, they will be given each one like its turn for sending its data,so that in one time  only one end device is communicating with coordinator?

-If we have to make our scaning all devices method for collecting one by one node data to cr : how to extract the list of nodes that joined our cr : or our asscoiated network autorised nodes (all their  64 bits adresses)?

Can you give us advises about jennic network CR and  ED global idea of how should be collecting data done via wireless for  safe trustable and fast ways of collecting data from end device stations,we could not find any suitable and understandable answers from forums or documetations.

Thanks in advance

DOUMANDJI.s
Electronic Engineer
www.argebilisim.com