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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52 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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5answers
97 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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2answers
59 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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48 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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2answers
156 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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2answers
70 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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1answer
84 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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1answer
55 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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44 views

Extending a 433 MHz antenna connected to a PCB

I want to convert a standard 433 MHz temperature sensor so I can use it to monitor the pool temperature. I can enclose the PCB and the batteries in a waterproof container. The pool is salt water ...
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1answer
190 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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168 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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1answer
457 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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1answer
41 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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0answers
99 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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3answers
924 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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1answer
188 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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2answers
128 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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3answers
244 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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1answer
675 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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2answers
155 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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2answers
226 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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0answers
65 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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2answers
620 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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1answer
810 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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492 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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0answers
155 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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1answer
108 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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1answer
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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1answer
180 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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1answer
298 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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0answers
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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2answers
467 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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1answer
255 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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0answers
649 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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2answers
3k views

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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1answer
9k 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
937 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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1answer
79 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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1answer
747 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 ...
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2answers
2k views

Using cheap RF module encoding with UART in a commercial product

For my graduation project, I need to design a system that transmits several different data packets to the computer wirelessly. It needs to have a potential to be commercial product, so both functional ...
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1answer
4k views

Test circuit to confirm RF receiver frequency? (315Mhz vs 433Mhz)

I've bought a 433 Mhz Transmitter/Receiver pair, or so I think. I cannot make them work, and I started to think that maybe the seller sent me a 315Mhz transmitter / 433 receiver pair by mistake (I've ...
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2answers
6k views

Datasheet/screw function on XY-MK-5V 433 MHz receiver?

I cannot find a datasheet for my 433 MHz receiver (which seems to be a XY-MK-5V), which looks like this: Also, I was wondering what is the use of the screw (on top of the green box with copper wire ...
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2answers
84 views

Unexpected bits when shifting out (ATtiny85)

I'm trying to spoof a 433 MHz remote and I have a sequence of 32 bytes that I want to repeatedly shift out to one of ATtiny85's pins. The signal then goes to a cheap Chinese-type 433 Mhz transmitter. ...
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1answer
2k views

Duplicating a KeeLoq Remote Control

I have been reading the documentations about KeeLoq Encoder and Decoders for some time. My goal is to build both the Transmitter side and the Receiver side using the KeeLoq system. I almost completed ...
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4answers
7k views

Can a RF 433.92 Mhz transceiver communicate to a RF 433.42 Mhz Receiver?

I am working on automating my Somfy Blinds. The idea is to avoid using the remote control which works on 433.42 Mhz and use a simple RF transmitter and an Arduino. The thing is that I can not find any ...
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3answers
640 views

433 MHz VS. Manhole Cover

I'm working on a sensor which purpose is to measure the water level of a sinkhole without getting in touch with the wastewater. The Sensor is mounted beneath the manhole cover --> The underside is ...
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2answers
3k views

Clone garage door opener [closed]

I have a garage door opener that I got when I moved into my condo. However, I only have one, and we have three vehicles in total (1 car + 2 mopeds). I want to permanently have a garage door opener ...
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1answer
2k views

Noise presence at a 433Mhz receiver

I'm playing around with these 433Mhz transmitter and receiver modules in combination with and Arduino Uno. I first soldered a 17cm long helical antenna to both modules. After I while I noticed that a ...
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2answers
1k views

What unlicensed frequencies can (or should) be used for proprietary wireless communication? [closed]

I can see that most of the gadgets that use proprietary protocols use 433MHz, 915MHz, or 2.45GHz, but I don't understand why. 433MHz is highly regulated in the US and 915MHz can not be used in Europe. ...