Using other than a wired connection to transfer signals or power. Includes optical and (ultra)sound, but most often refers to RF (radio-frequent). Distances can be as low as centimeters (e.g. RFID), there's no upper limit.
11
votes
3answers
507 views
What's the purpose of such weird wiring inside this smart card?
Here's a scan of a stripped MIFARE Ultralight smart card
That's some plastic film with (I assume aluminum) foil wiring acting as the antenna for both powering the chip and providing radio ...
3
votes
3answers
413 views
Wireless Sensor to Internet
Looking for a low cost implementation to post ambient temperature readings from a sensor to servers via a COTS router.
1) Have a temperature sensor connected to a micro controller which sends data ...
2
votes
3answers
200 views
Can I transfer data wirelessly to the inside of an aluminium can?
My problem is that I have to control (turn on and off) one LASER that is placed inside an aluminium can (not like soda can, but one 2 mm thick).
So the question is if there's any way to do that ...
0
votes
1answer
481 views
What is the typical range of a nRF24L01+ module with PCB antenna?
I have seen the nRF24L01+ ( http://iteadstudio.com/store/index.php?main_page=product_info&cPath=7&products_id=53&zenid=qa08tp07o8bn54mjpo155e5o1 ) module linked before as a solution for ...
1
vote
2answers
213 views
Anyone know of a good/cheep usb dongle to pick up ULF (.3 - 3kHz) radio?
I've bought a pack with 3 temperature senders and 1 receiver. But I want more, and I also want datalogging.
Is there a USB dongle that let's me pick up on a given frequency, lets say '433.92 Hz' and ...
2
votes
2answers
249 views
Can 5okW be transferred using resonant wireless power transfer?
I don't mind efficiency or loss, but simply can it be transferred? I'm wondering more about the size of the receiver than the transmitter. If the receiver is positioned within the power transfer field ...
1
vote
3answers
151 views
Sending and getting commands through the Internet
I have a little chopper (adult toy to be exact) that can be controlled by the controller within 30 metres. What I have in my mind whether I can send commands to this toy chopper though the Internet, a ...
0
votes
2answers
268 views
IR TV/Satellite remote control
I was searching the web to get full knowledge of IR remote controls. My satellite receiver (Humax)'s remote control got ruined. So, I unscrewed the remote control took a look inside it. I know IR ...
1
vote
0answers
81 views
Simple embeded linux system optimal for wireless routers [closed]
I was considering starting a little project that involves extending the base role of a router to being somewhat of a home server(they're basically linux servers anyway)– but I'm more of a software ...
3
votes
0answers
343 views
Upgrade ARM over the air
We will create an ARM board with a GSM modem on-board.
We want to be able to upgrade the ARM firmware over the air.
Is there any good, reliable, open source solution for that?
If not, is there a paid ...
0
votes
0answers
217 views
Is there a wireless shield for the Teensy? [closed]
Is there a wireless shield-like adapter for the Teensy? It would be much better to put in more product-like things than an Arduino with a wireless shield.
1
vote
1answer
82 views
Is it possible to use USB port with a transmitter to control a robot
I have a project in mind that works as a robot accepting input from the computer through a male connector.
I have seen the circuits that use a wire system to connect to the robot. But is there any ...
3
votes
2answers
207 views
Sending data over a magnetic field
I need to find a way to trigger this Hall Effect Sensor with a non-permanent magnet. Does anyone know if an inductor's magnetic field would be strong enough? Or am I going to have to build an ...
4
votes
2answers
338 views
What is the ratio of antenna length to power?
A question that came up in class; what is the relationship between length of a solid cylindrical antenna (wire) and transmission power? I would imagine it's frequency dependent
2
votes
3answers
1k views
How do I shield a card like Visa payWave and MasterCard PayPass to block its communication?
This is basically a replication of this question on Personal Finance SE. Suppose there's a wireless smart card like Visa payWave or MasterCard PayPass or MIFARE Ultralight. The owner wants to ...
0
votes
2answers
652 views
Realtime Wireless Heart Rate Monitor
I'm familiar with Assembly/C/C++, so this question is focused on the hardware side.
Context: I want to have a real time heart rate monitor so that I can see, on my computer screen, my heart beat. ...
2
votes
2answers
419 views
Cheapest way to wirelessly synchronize two MCUs
I have two battery powered MCUs about 30cm apart, one will be the master, and one the slave. Each MCU has several LEDs connected which flash in a sequence.
All I want to do is synchronize the two ...
5
votes
2answers
1k views
Improve range of 433MHz RF link
I have a system comprised of a wireless sensor which transmits temperature readings to a main base.
The wireless sensor system is made up of:
12F683 pic to take the temperature reading (manchester ...
0
votes
2answers
217 views
RFIDs versus Bluetooth
In terms of object tracking, I'm working on making a small device/tag that uses bluetooth technology to keep track of objects but a friend told me about RFIDs which are supposedly cheaper and also ...
-1
votes
2answers
188 views
VSAT link between station A and B bandwidth is limited as QPSK modem 4096kps?
I'm finding it difficult to solve this problem and I am hoping y'all can help me with it. How can I optimize a VSAT link for maximum data throughput from a station A to B knowing that our measured ...
2
votes
2answers
1k views
Connect UART WiFi module to PC
I recently bought a UART WiFi module ( this one ) and configured it (wireless configuration method) with right SSID but wrong password( and I don't know what it is ). The problem is that I can't reset ...
1
vote
1answer
219 views
Adding 3g wireless capability to an embedded project
How would I go about adding 3g wireless capability to an embedded project? Initially I thought about just using a USB host controller and purchasing a USB 3G card. This idea however seems "hackish" ...
0
votes
2answers
310 views
UDP Like Protocol for XBee
My situation is as follows, I have a robot that has 4 motor controllers attached to an arduino that has a xbee series 1 connected. Xbee has its default settings except baudrate which is set to 57600. ...
2
votes
3answers
941 views
Arduino Wireless USB Cable
I am new to both arduino and electronics. Where would I start making a wireless Aduino USB cable. Which readings or websites can I go to for more information? PLease help...:)
This cable should be ...
6
votes
2answers
514 views
How to build a cheap device to determine where Wi-Fi interference is coming from?
In this post, the ServerFault guys use a fancy tool to map out the WiFi spectrum under normal conditions, with a microwave running, and with a baby monitor on. The baby monitor and microwave cause a ...
-4
votes
1answer
232 views
High bandwith/ low latency wireless sensor network
I have a field of anywhere from 16 to 32 sensors that have to all transmit around 2Mbps simultaneously and continuously (I could possibly bring this down to around 1Mbps if it is the only way). The ...
2
votes
1answer
765 views
XBee wireless module not responding any more
I bought an XBee-PRO S1 .. I built its serial explorer to be able to configure it through the PC, I’m using X-CTU to configure and test it at first it worked well,I made test/query successfully ...
3
votes
1answer
108 views
How to sync sensor data
Suppose I have multiple dataloggers receiving sensor data, how can I sync those signals afterwards? The most obvious way would be adding timestamps to the data, but they have independant clocks, so I ...
3
votes
3answers
513 views
Telemetry Antenna
I am developing a telemetry system for a solar car. I am going to be using xbee chips to communicate from the base-station/chase-car to the solar car. The xbee chips are 900MHZ, or 2.4ghz. I am ...
1
vote
1answer
487 views
Building a small 3-axis accelerometer mote
I'd like to build a remote device which reports its current 3-axis acceleration to a nearby (<10m) receiver. It needs to be as light and as small as possible. (I have no preference as to the ...
5
votes
1answer
133 views
How does k-nearest neighbor apply to wireless network positioning?
I'm trying to gain some insight into the variety of positioning algorithms for wireless networks. Apparently there are three categories of algorithms: distance estimation, scene analysis and ...
2
votes
1answer
2k views
Wireless Audio Transmitter
I am working on a project that will digitize an audio signal from a standard RCA jack and transmit that signal using Bluetooth to a receiver and then convert it back to an analog signal which I will ...
3
votes
2answers
4k views
What will it take to build a small bluetooth device?
I am new to this part of StackExchange. I am doing a project that requires me to keep track of Bluetooth devices. So I want to build a tiny Bluetooth device that can be attached to almost anything; ...
7
votes
6answers
4k views
ultra low power mini wireless transmitter / receiver?
I'm looking for suggestions for a wireless transmitter & receiver combination. I'm basically just trying to bridge several buttons over a wireless signal(s) (i.e. send a 1 bit signal) in as small ...
0
votes
4answers
394 views
How to profile the communication protocol of my Microsoft Arc wireless keyboard?
I bought a new keyboard for windows, datasheet, and I would like to sniff the packets between the keyboard and the pc / USB transmitter.
The datasheet is useless and there is nothing informative for ...
9
votes
5answers
552 views
Fault modeling for embedded systems
I have a wireless sensor circuit with a microcontroller and a 2.4 GHz transceiver module, some integrated sensors with I²C interface, a UART port and the necessary discrete components.
This board is ...
7
votes
4answers
766 views
MIMO: How Can Two Antennas So Close Together Receive Different Signals?
I'm trying to understand how MIMO (as used by 802.11n wi-fi and some upcoming cellular data standards) works in practice. I understand at least the gist of the theory of spatial multiplexing. What I ...
-1
votes
1answer
239 views
Need an advice with choosing FPGA kit to be used for wireless application [closed]
I need to implement a Wireless (802.11n) firewall as a FPGA application, so basically what i need is an FPGA kit that can handle the trans-receiver part for me, while giving me the ability to process ...
2
votes
2answers
711 views
Is there any difference between “induction” and “resonant” wireless energy transfer?
This article compares two systems for wireless energy transfer - one is by WiTricity and another is Bombardier PRIMOVE. I've read their descriptions thoroughly - to me they both look like resonant ...
6
votes
4answers
555 views
How is inductive wireless charging of a moving vehicle on a public road possible in efficient way?
Looks like one of the major problems of wireless energy transfer is efficiency. For example, Magne Charge high power charging system seems to have about 86% efficiency which means that quite a lot of ...
3
votes
1answer
328 views
What's the need for higher frequency in inductive charging systems?
Consider an inductive charging system like Magne Charge - it has a rather huge "coupler" coil off the vehicle and a corresponding slot on the vehicle and the coils in the "coupler" and in the slot are ...
7
votes
1answer
278 views
Why does short distance wireless energy transfer have such low efficiency?
Wikipedia and numerous other sources cite the following statement about Magne Charge high-power inductive charging system:
For example, the Magne Charge system employed high-frequency induction to ...
1
vote
1answer
215 views
Multiple radio in a small dimensional sensor node PCB
I'm planning to develop a wireless sensor node that equips dual IEEE 802.15.4 radios.
Although the board will equip homogeneous dual radios, both of them will operate at different channels.
Regarding ...
3
votes
5answers
4k views
Best way to send sensor readings over simple RF connection
I have bought a pair of simple 315MHz TX/RX modules. I want to use these to connect a battery powered ATTiny85 to an Arduino base station. The ATTiny needs to regularly wake up and send a sensor ...
0
votes
0answers
142 views
Logging wifi chip address?
I would like to use an Arduio + wifi shield to grab unique mac addresses of any wifi chips within range, these will then be sent to my home server. Right now my chip creates an ad-hoc wifi network ...
2
votes
3answers
1k views
Easiest Wifi module/shield to interface with Arduino Fio? [closed]
This is my first time doing any arduino build, and I'm planning to build a digital hydrometer/thermometer for home brewing. I'd like to either run a simple webserver on the arduino or transmit the ...
3
votes
2answers
342 views
Anyone got any idea what type of antenna these Wireless routers that have no “visible” dipole antenna on the outside use?
Referring to these type of wireless routers' antennae like : Netgear N150 and Linksys E1500
3
votes
1answer
160 views
How many concurrent senders can CDMA support for a code length of n?
I understand how CDMA works (kind of). I'm just not sure how to go about figuring out how many orthogonal signals can be produced from a code length of a given number.
2
votes
3answers
553 views
Low-cost, low-range RF transceivers
Basically I need a low-cost wireless communications module. My requirements would be ~10bit/s , ~2-3m range and up to 1$ for each. Can be receiver and transmitter separately as well. I think it should ...
3
votes
2answers
114 views
Making mesh sensor networks energy efficient
SCENARIO:
Say you have a mesh network of sensors that measure something like ambient temperature. The nodes are out of range of the base station; however, there happens to be one intermediate node ...
