Questions on the implementation of Wi-Fi (802.11) hardware. Note shopping questions are off-topic.

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2answers
49 views

Is it a best option to use IRF9540N P Channel Enhancement mode MOSFET for switching 3.3V to my WiFi chip?

I am using IRF9540N P channel enhancement mode MOSFET for switching 3.3V to the power pin of the WiFi chip. The connection is as follows Source --------- 3.3V Drain ---------- WiFi chip power Gate ...
1
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1answer
34 views

Ceramic antenna for wifi applications

I want to ask how to choose correct ceramic antenna for wifi applications. I've very tight space constrictions and I need to use a small smd antenna. Which is the best antenna(characteristics) for ...
0
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0answers
17 views

Tosr-0x relay board from tinysine with wifi bee V1r1 wifi network question [closed]

I have a 4 relay TOSR02 relay board controlled by a wifi bee from tinysine. I have got it working but am trying to get it to operate on my local wifi network using the ios app. I can ony operate it ...
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0answers
25 views

Wifi and Bluetooth in single board

I am trying to build a system which will have a USB camera and stream the video via wifi. I am using one of those chinese high speed wifi modules from a company called shenzhen Ogemray. The wifi ...
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2answers
102 views

How to request “GET” from an ASP.NET website using ESP8266?

AT+CIPSTART="TCP","zgrdataserver.com.azhar.arvixe.com",80 OK, works. AT+CIPSEND=92 The response is ">". Works fine, but ...
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2answers
55 views

Connecting to Wifi over Bluetooth for embedded systems

I know that these two (Wifi and Bluetooth) are in the same range of frequency (2.4 ghz. At least mine ones are this way). I do not think wifi modules for embedded systems (I use AVR) are cost ...
1
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1answer
62 views

Is CE marking on module necessary?

Suppose a RF module has passed CE EMC tests. Must the CE marking be printed on the module itself in order for the approval to be valid if it is to be used in an end product?
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1answer
99 views

Is moving fast will effect WiFi transceiving beavior?

Let's say I'm driving a 2010 Bugatti Veyron 16.4 Super Sport, with speed of 431 km/h = 268 m/h = 119 m/s Now I have a WiFi signal receiver installed on the top of the car and a WiFi transmitter in ...
4
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1answer
80 views

How to ensure a RF module is indeed FCC compliant as advertised?

Suppose a buyer buys RF modules from China and wants to ascertain that they're indeed FCC compliant as advertised. I'm guessing that this should be a fairly common issue since Chinese ...
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1answer
61 views

Which is the better way to send a broadcast signal to a great number of smarthphones in the same place? [closed]

I wonder which could be the better way to send a broadcast signal to a great number of smartphones in the same place at the same time? I'm thinking about 10.000 to 50.000 smartphones in an area of ...
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0answers
64 views

What happens if a FCC certified module isn't what it claims to be?

Suppose a radio module is already certified by the FCC but the manufacturer decides to ship inferior versions of it without acknowledging that fact, making users oblivious to the change. Do commercial ...
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3answers
493 views

What kind of metal are RF shields made of?

With the shields typically found on WiFi modules, what kind of metal are they? Are they coated? Here's an example: Thanks
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2answers
61 views

Could the metal shield on radio modules be tampered with?

I see that most radio modules have a metal shield. Is it for keeping the radio waves inside? If so, could a shield be too thick for its purpose? For instance, if one solders another piece of metal ...
3
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1answer
119 views

Must FCC-certified modules be labelled with the correct FCC ID?

The manufacturer of this radio module I bought claims that it's FCC certified, but there's no FCC ID on it (though there is the FCC logo). If the final product is to be FCC tested, would it then be ...
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0answers
27 views

BlueGiga WF111: SDIO host interface and SPI compatibility

I am planning to use the following in a project: Olimex A20-SOM-4GB (Allwinner A20 SoM) BlueGiga WF111 Wifi b/g/n module The WF111 module has only one host interface, which is SDIO (1-bit by ...
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0answers
38 views

Impedance matching circuit for ESP8266

The datasheet of ESP8266 says that the impedance matching circuit should be 50 ohms. The ESP-01 uses a L-C-L filter. The value of capacitor is 5.6 pF. What should the value of the inductors be? How do ...
0
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2answers
98 views

TCP/IP stack for wifi module

I keep reading about TCP/IP stack for wifi module. I am having bit difficulty to understand that. I am working on hobby project in IoT and need to choose wifi module for Atmega328P. I heard about ...
1
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2answers
47 views

Antenna mounting question

Here is the datasheet and drawing of the antenna on this link I need to stick out the antenna from a thick metal enclosure, how much of the antenna should stick out? Is it 19 mm (the black rubber ...
0
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0answers
111 views

How to connect Xbee to FPGA using SPI?

I am trying to connect an Xbee to a FPGA using SPI. I found some code online to read in the MISO and convert to an 8bit output register. I have it working in the simulation but I cannot get the ...
1
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1answer
251 views

ESP8266 Wifi Module - prints “ready” but not responding to AT commands

Just received my first ESP8266 wifi module with some excitement. However I've been unable to fully communicate with it. I have connected the module to my computer via a usb to serial cable and I'm ...
0
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1answer
21 views

connecting wifi module to proxy based wifi

I have a wifi module with micro-controller , but my college wifi uses proxy, SO how can I program proxy credentials in my C program so that my wifi module connected to micro-controller can connect to ...
0
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0answers
69 views

Bluetooth LE versus WiFi latency?

How do the best case and typical latency times differ between using WiFi and Bluetooth LE to communicate quickly between two nearby devices capable of using either of these 2 standard wireless ...
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0answers
50 views

Converting USB webcam to wireless

I have a PC workstation and a usb camera installed about 5m away. There is power available at the camera but the USB port is now broken. It is prohibitively expensive to replace as it is installed ...
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1answer
66 views

how to make an amplifier system to boost my wifi over large distance? [closed]

I am keen to know if I can build a amplifier system which would take my wifi signal as input and boost it over large distance. I know wifi repeaters are out there but I am looking for more powerful ...
0
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1answer
79 views

wifi / WIMAX antenna

What the different between WiFi antenna and WIMAX 4G antenna?, I want to boost the signal for my router to 4 km, I found this antenna in local store, but it seems weird there is only 1 leg, not like ...
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2answers
73 views

Circuit board layout: wifi ceramic antenna next to a electromechanical relay

Is it okay to place a small ceramic antenna not far from a electromechanical relay? Would the magnetic field generated by the relay coil (when on) affect wifi operation? clarifying edit: not far = ~1 ...
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0answers
27 views

IEEE 802.15.4 standerd

According to Wikipedia the said standard defines physical layer and media access control (MAC) control for devices working in the Sub-1 range. However I noted that this standard is not similar to ...
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0answers
42 views

HF RFID 13.56MHz Interference from WiFi/BLE 2.45GHz?

If a Wifi/BLE antenna were placed within a multicoil loop antenna for 13.56MHz HF RFID, would there be significant crosstalk/interference?
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1answer
167 views

How to connect FPGA to Xbee? [closed]

How can I connect an Xbee to FPGA to transmit data.
2
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2answers
112 views

Why do wifi channels overlap?

In the United States and Canada there are 11 channels available for use in the 802.11b 2.4GHz WiFi Frequency range defined by the IEEE. But there are only 3 non-overlapping channels available in the ...
0
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1answer
31 views

Wifi Channel vs a Sub 1 GHz channel of same width

If the same channel-width is allocated for a WiFi channel and also for a Sub-1 GHz channel, would the maximum allowable speed be the same for both channels theoretically? If they differ, what is the ...
0
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1answer
88 views

RSSI measurements near wifi router

I have a question about RSSI and EIRP. When I bring my smartphone very near my antenna wifi router (+20 dBm EIRP) the analyzer wifi application shows me an RSSI level about -20 to -25 dBm (a negative ...
0
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1answer
88 views

How to find out Packet Loss in a Broadcasting environment

Indeed packet loss is an important metric to use when comparing different communication protocols. To me it is understandable how one would computer Packet Loss in a unicast transmission. Simply the ...
0
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1answer
80 views

Best MCU platform with over-the-air firmware flashing capability? [closed]

I know spark.io is well known for this feature, but I'm searching for alternatives that offer hassle-free over-the-air firmware patching and has also some open implementation examples available. ...
1
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1answer
104 views

hlk-m30 WebClient example

I have started working on HLK-m30 WiFi module. I am developing the simple client on the module using simple AT commands. I have Opened socket TCP client and then Write data using the command. ...
2
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0answers
26 views

802.11 Channel Use Regs

With a 5.8Ghz WLAN device, operating in the upper UNIII band, 5745mhz-5825mhz... ...is it required that if the device is using a standard 20mhz wide 802.11 channel, that you can ONLY be centered on ...
1
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2answers
148 views

What chips do 3$ wifi dongles use? [closed]

I saw lots of WiFi dongles withing the price range from $2,50 to $3,50 (eg. this one). I am current doind a project using a microcontroller with usb, that requires WiFi. I'm interested what kind of ...
0
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1answer
78 views

Simple Serial-to Wifi communication

I'm working on controlling an incubator by writing commands to its serial port, a 9 pin RS232. The commands are simple byte strings, such as #02ts. The incubator responses are similar to the ...
0
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0answers
75 views

If my WIFI chip has poor performance at 5GHZ, what does that mean to the end user?

I'm testing my WIFI chip, and it has poor performance at 5GHZ. The transmit power I'm measuring is really low. How does this problem manifest to an end user? Will the internet connection be really ...
0
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1answer
76 views

using supermalloy as the core for wifi loop antenna

this is an extension of this question: Why aren't ferrite rod antennas used in WiFi? if you don't want to go through the previous question, then basically i was asking if we can loop wifi ...
7
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2answers
1k views

Why aren't ferrite rod antennas used in WiFi?

Does it have something to do with soft ferrite's low coercivity, still not low enough at gigahertz frequencies? See, I'm putting together high gain receiver antennas and transmitter antennas. Space ...
0
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1answer
81 views

Why can current phones act as Wi-Fi routers, but not as mobile broadband (3G, 4G etc.) routers? [closed]

Many of today's smartphones enable users to share their own internet connection with others via Wi-Fi through tethering. However, from what I understand, current Wi-Fi has much shorter range and ...
1
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2answers
256 views

ESP8266 serial-wifi: antenna options

The cheap ESP8266 boards are offered on ebay with two built-in antenna options: with a PCB trace antenna with a ceramic(?) antenna (PCB photographs see below.) Has somebody bought both and ...
0
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2answers
106 views

How can the 2.4GHz ISM band have 130+ channels?

I am a relative beginner regarding wireless communications protocols and I am looking into the protocols used by toy helicopters, in particular the Hubsan X4. According to more experienced people who ...
0
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2answers
222 views

Using adafruit Flora or Adafruit Trinket + MPU-6050 3-Axis Gyroscope + nRF24L01+ together

I am trying to do a project where I need to transmit data from an object if the object is moved in a particular way. The restriction is that the device has to be as thin and small as possible. I am ...
0
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0answers
39 views

Any parameter other than RSSI in latest wifi standards, which can help estimate distance between wifi AP and endpoint

I have checked and found many references for measuring distance between wifi AP and connected endpoint based on RSSI. But in order to do this, does latest wireless standards produce any parameters ...
0
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1answer
41 views

Access the internal clock on WLAN chips

I am trying to implement a localization method based on WLAN round trip time (RTT) ranging. Some of the papers I have read suggest doing ranging based on the MAC layer RTTs (beacons, ACK, RTS/CTS ...
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4answers
114 views

Will having two antennae at the receiver give better reception?

I have a 300mbps router with two antennae (tp-link td-wd8968). I'm building a PC and looking for a wireless network card. I have seen seen cards with a single antenna (150mbps) and cards with two ...
0
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1answer
48 views

How choose MPU for image streaming and transmission

I want to ask how to choose and how much processing power are required to be able to stream video using a wifi module. I'll explain better; I have a camera sensor of 5Mpx, i want to elaborate video ...
0
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0answers
64 views

Bluetooth antenna design

I am building a system with bluetooth/wifi/GSM. Since I am an RF noob, I have some questions regarding antennas. Some modules come with loop antenna and if you want to create your own PCB there is a ...