Questions tagged [433mhz]

433MHz is a license-free area of the RF spectrum in many countries. It tends to be restricted to low power and bandwidth but allows simple modulation schemes making it popular for low cost / bandwidth applications such as keyless entry and alarm systems.

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43 views

Taiwanese Regulations of 433 MHz

I'm designing a wireless commercial device to be sold in Taiwan. I'm looking for transceiver modules, some of them work at 433MHz. However, I'm not clear if the 433 MHz is regulated in Taiwan. Does ...
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40 views

Recent reference for “why not to build RF circuits on breadboard”

I've noticed the occasional I've built my FM modulator/RF mixer/433 MHz oscillator according to plans from The Internet on a breadboard, now it doesn't work. We can usually refer the author to ...
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What dimensions would L1 in this 433MHz tank circuit receiver be if it is actually 1.5 turns?

Specifically, this circuit from Elektor: The asterisk denotes that L1 in this 433MHz receiver circuit would be 1.5 turns. If that is accurate, what would the dimensions of the inductor air core be? ...
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70 views

On which layers of 4 should the trace antenna be (433MHz)?

I have designed a simple PCB with the follow layers Top Layer, high speed traces (rest ground copper) Inner 1, Ground Copper area everywhere apart on the very left side where the trace antenna will ...
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2answers
54 views

which antennas is better for 433 Mhz 30dbi LoRa module [closed]

I am searching a antenna for LoRa module. my first priority is distance. which is more long range, it is better for me. There are 3, 433Mhz 3dBi antennas. Can you help me which is best and why? if you ...
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90 views

Are there generic generic repeaters for 433 MHz communication (such as for doorbells)?

I'm having a 433 MHz doorbell which is too far away from the receiver (too many walls in between). Sometimes it works but other times it doesn't. I thought that there could be a 433 MHz repeater (just ...
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38 views

433 MHz Antenna Layout

I'm trying to build a remote control unit and want to 'remote' the antenna from the 433 MHz Tx unit. I'd appreciate some feedback before I order as my antenna/RF theory is sketchy and I want to know ...
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54 views

On a PCB, can an antenna for 433MHz RF be “far” from the transceiver?

When I design PCBs I always try to keep antenna as close as possible to the transceiver. Now due to the design I need the transceiver schematic on the left side but the antenna on the right side of ...
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79 views

Circumvent 433MHz antenna printed on PCB

I'm tinkering on a cheap chinaware alarm center which receives signals from its detectors on 433MHz. It is located inside a metal box which forms a faraday cage and apparently reduces the range too ...
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2answers
98 views

Can a similar crystal and not exactly the one on the datasheet be used on RF 433 receiver?

The datasheet of SYN531R suggests 13.51783 MHz crystal. I found available available 13.52127 MHz on an online store. It seems very similar to me, however in reality would it work and if yes, would it ...
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74 views

Car Key Fob doesn't transmit RF, althougth everything else seems to be working

Before starting to describe the problem, I need to say that this is my first time posting on electronics.stackexchange. I don't have a deep knowledge of electronics but I usually can diagnose a ...
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64 views

433 MHz Transceiver - understanding OOK demodulator parameter 'OokFixedThreshold'

I would appreciate some help to understand a parameter for this device https://www.semtech.com/products/wireless-rf/fsk-transceivers/sx1231h. I'm far from an expert at RF matters and this question has ...
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107 views

Determining the transmit frequency of a key fob

How can I determine the frequency of this RF module (car keyfob?) It should be 433 or 315 MHz. I have a 50MHz digital oscilloscope. Is there a way?
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150 views

Generic 433MHz receiver, how to derive output signal voltage

I have a 433MHz receiver modules (Model number MX-05V) The input voltage is listed as 5V but they don't list the output voltage. I have seen this used without level shifting in a project in ...
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62 views

5X5 button matrix with 433Mhz rf module or NRF module

I have interfaced 433Mhz rf module and custom 5x5 button matrix with arduino. Keeping Keypad matrix at transmitter side and an LED on the reciever side as long as i hold down the button the led should ...
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296 views

433 MHz Antenna - Balanced Dipole + Balun?

I've got three 433MHz receivers (all the same type) and I would like to increase the range on them (by which I mean the physical distance that the receiver can detect the signal from the transmitter). ...
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75 views

Communication within 5-10 meters: RS-485 or Wireless?

As a follow-up for my previous question, can anyone please recommend for my application (communication between two floors of a building) as whether to use RS-485 or any wireless technique (I am ...
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178 views

433 MHz receiver consumes too much power

I bought one of this modules (link), with the SYN470 chip on it. In the datasheet it's mentioned that in continuous mode with 433 MHz the current consumption is 3.9 mA which is a lot in my case. But ...
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84 views

In RF433 Mhz module What is the Bandwidth and Data rate that used to transfer data?

many of document I have read it that tell me this module has 2MHz and Data rate equal to 10Kbps and using ASK modulation how did it transfer 10Kbps on 2MHz what my question is why did used a large BW ...
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472 views

Is there any country where the 868 MHz or 915 MHz ISM band cannot be used?

The product I am working on (Electronic Shelf Label) uses the 915 MHz radio frequency band and is currently being deployed in Asia. I am gathering the list of countries that the 915 MHz frequency is ...
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229 views

Where to solder antennas on 433mhz receiver/send

I bought some 433mhz senders and receivers and some 433 mhz antennas. Unfortunately I don't know where to solder the antennas. Where do I solder the antennas to and do I need special solder wire? ...
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585 views

HC12 Serial RF Transceiver with PIC16F886 Microcontroller

I'm trying to do a wireless communication between two PIC microcontrollers (PIC16F886) using the TX/RX lines using HC-12 RF transceiver modules (datasheet link below). https://statics3.seeedstudio....
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47 views

CI HT12E enable control to reduce power consumption

So, following this datasheet (check out Application Circuit 4), I managed to transmit a signal and receive it on the other end. The thing now is: the whole circuit is drawing 2 mA, and that is because ...
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115 views

Unable to intercept the code of my remote control at 433 MHz with RaspberryPi

I'm trying to reproduce the code generated by my universal 4-channel radio control with ...
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1k views

2.4GHz WiFi module causing interference on 433MHz RF receiver module

I have a prototype board which has two RF modules on it, a 2.4GHz Wifi module (ESP-01) and a low cost 433.92MHz RF receiver module (Wenshing RWS-371F-6). My 433MHz transmitter (a remote control) sends ...
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229 views

How does this 433Mhz garage remote control work without an antenna?

I have a 433 Mhz garage remote control that works very well even from 30 to 50 meters and it has no antenna! How is it possible that it works so well without an antenna? Also, given the picture of ...
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160 views

Does the 433 MHz transmitter/receiver, transmit the voltage?

The title, says it all... I would like to know if the 433 MHz transmitter/receiver (couldn't find a datasheet, here is all I found on it) transmits the voltage, ...
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266 views

I2C noise from 433MHz transmitter

I have built a little thermostat based on BMP280 temperature sensor over I2C, ESP8266 Lolin v3 and STX882 433Mhz transmitter. I have not added additional pull-up resistors or decoupling capacitors. ...
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1answer
32 views

Antenna Gain Vs IP68 plastic enclossure

I would like to buy this IP68 plastic enclossure below for my electronic project: https://www.chinaenclosure.com/products/102-70-52mm-ip68-waterproof-plastic-enclosures-for-electronics-from-china-...
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787 views

Itead Sonoff RF WiFi & 433MHz switch: Identifying an unknown chip on the 433MHz card

I have the Sonoff RF which is a mains relay switch which is activated by either WiFi or a 433MHz remote. The particular Sonoff RF's I have arrived from China on 21/9/2017. I flashed these Sonoff RF's ...
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182 views

Is it possible to replicate a Novotron 522 remote control?

The signal I want to replicate is to open/close a garage door, operated by a Novoferm motor. The remote control used is a Novotron 522. The description states this is 2-channel remote control, ...
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244 views

Can I use the same antenna for GSM and RF433 MHz?

I've already designed a PCB with GSM/GPRS chip and also with RF 433MHz receiver only (without transmitter). I would like to know if I can use the same antenna for both GSM/GPRS module and RF 433MHz ...
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92 views

Microphonic SAW transmitter?

I built this very simple SAW transmitter, with a simple "spring" antenna for the right frequency. To test it, I tuned a portable receiver to around 433.92Mhz and fine tuned it until I heard silence. ...
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745 views

RF Design / Calculations - 433.92MHz, PCB antenna, values of capacitors

I'm doing a RF remote control project using a PCB with microcontroller and with simple onboard antenna layout as transmitter and a 433.92MHz receiver RWS-371F-6 model. Here is the datasheet of the ...
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926 views

433Mhz Remote Control Antenna Selection

First I want to thank all of you who come here and help others. That is very kind and unselfish of you! This is lengthy but I want to make sure I tell you everything you need to know to answer this ...
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598 views

How does this transmitter work/how to tune it?

I have used a few 433MHz ASK transmitters. They're cheap, readily available, and work reasonably well. Based on this application note from Murata I tried to build my own. I replaced the NE68030 ...
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158 views

Antenna selection for CC1101-433 MHz rf

I intend to use these TI CC1101 433 MHz RF modules in one of my project: Wavelength of 433 MHz will be 69 cm. Half wavelength will be 34.5 cm. Vendor is selling two antenna options with the product. ...
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113 views

Easiest way to control a led remotely [closed]

I was wondering what is the easiest and cheapest way to have a high power led (3 Watt) turn on/off and blink remotely from a distance (60m-100m). I've been looking at some microcontroller solutions (...
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2k views

what is the good antena length for 433Mhz modules used for low distance domestic usage?

I want to use a low cost 433Mhz module for low distance domestic usage, but I need to solder an antenna , (there is a place for that on the reception module), to get a better signal across my walls. ...
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193 views

Signal loss failsafe for a cheap drone using 433 MHz tx/rx pair

I bought a cheap drone to get into flying quadcopters and it seems it has only one big issue at that price, which is a very long failsafe time of 20 seconds, i.e. if the remote signal is lost, the ...
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306 views

Creating a wireless transmitter/receiver for off-the-shelf siren

Since I oddly enough haven't been able to find a suitable off-the-shelf product that's reasonable priced (less than 50-60 EUR/USD) and somewhat good looking with Google, I'm about to try a small ...
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1k views

How to analyze/decode a Manchester encoding? [closed]

I have a barcode scanner working on 433Mhz (FSK). Since this is a relatively old product and the PC software is not working with Windows 10's and I can't use the SDK anymore. I, therefore, have ...
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574 views

How to derive voltage applied to an antenna, where transmitter power is known & identical tx/rx antennas are used with known gain/impedance?

Question: Imagine a transmitter + transmitter antenna with the following characteristics: 433Mhz transmitter transmitting 10dBm Into an impedance matched (50 ohms) antenna, omni-directional, 3dBi ...
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274 views

Fast, cheap, wireless data transmission with Raspberry Pi [closed]

I need some advice on a project. I want to wirelessly transmit packets of data from a Raspberry Pi to several microcontrollers (Arduino or other). The frequency must be at least 15 packets/s per ...
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676 views

A curious 433 MHz signal to decode

I bought a cheap set of remote controlled power sockets and I want to integrate them into my home automation system. So I got a 433 MHz receiver for 1€, connected it to my Arduino and tried to decode ...
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Why are two different length antenna sold with this 433MHz module?

I've stumbled upon this module. It is a set of receiver and transmitter module at 433MHz. This shows the antennas: With the lengths being given as: "external antenna: 25cm ordinary multi-core or ...
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10k views

How can I modify the frequency of a simple 433MHz transmitter module?

How can I change the frequency of a simple RF transmitter? These are the transmitters in question: Background Research On this question s3c says: To change the ...
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3answers
983 views

Servo interfering with 433MHz RF

I'm using an Atmega328P running at 16Mhz (similar to an Arduino UNO). to control a 433Mhz Superheterodyne RF receiver (WL101-541) and two TowerPro SG90 analog servos. Everything is working except for ...
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80 views

CC110L strange clock signal

I'm trying to hack my wireless thermostat to control my heating. I disassembled my unit and found the communication chip ( CC110L - SPI 433MHz). I searched for the datasheet and tried to determine ...
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809 views

where to solder antenna on 433 MHz remote control

I would like to install this remote into a carbon component, which apparently shields all rf signals. So, I need to solder an external antenna to this remote control pcb, but I could not figure out ...