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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Two different length antennas can cause problems?

I am using two 443 MHz transceivers (FY-605 transceiver) with both having different antenna lengths. One antenna is around 12cm long and the other antenna is around 17cm long. Will this cause ...
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79 views

433MHz quarter-wave length antenna: Longer is better?

I am trying to conduct an RF project using some cheap modules: link here My problem is that even though most blogs and Google searches for these modules use a quarter-wave length antenna (roughly ...
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Remotely Toggle Relay

A while back I decided I wanted to get into electronics, after which I bought a number of components to get me started, along with the Raspberry Pi and breadboard I already had. I am now wanting to do ...
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141 views

Arduino 433MHz transmission fails if falling edge is less than 122ms

I am trying to control a LED using a high-power 433MHz transmitter receiver pair, with transmitter connected to my Arduino Nano. Here is the transmitter (XLPCF20): ...
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3answers
410 views

Boost DC voltage converter for wireless temperature sensor (1.5V to 5V)

I'm trying to design a wireless temperature sensor powered by one (or maybe two) rechargeable NiMH AA cell(s). The sensor should read and transmit the temperature every couple of seconds and remain in ...
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143 views

Cloning Keeloq remote keyless entry system

Our house and a few other share the same gate, which is opened remotely by a 433Mhz transmitter. Unfortunately, we only get one remote per house, and we have two car. The company operating the gate ...
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540 views

433MHz RF transmission only working when holding usb cable in the air

I'm really puzzled about this. I have a simple transmission between two ATTiny85's going on with a 433MHz receiver and transmitter. The transmitter is in the basement so the signal is rather weak but ...
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Attiny85 hardware interrupt unreliable, 433 MHz remote

SCROLL DOWN TO SEE THE SOLUTION (UPDATE II) ORIGINAL POST: I am currently building a 433MHz remote with two buttons. The remote is controlled by an Attiny85v(8MHz). Sadly it does not work very ...
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Using RCSwitch and VirtualWire on the same Project

What is the easiest (and what is the most memory saving) way to use 433MHz power outlets and virtual wire. I want to control wireless controled power outlets and some wireless sensor nodes with my ...
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Boost 433MHz receiver module receiving signal (XY-MK-5V)

I am using some "no-name" (In Fact "XY-MK-5V" stands on the board) 433MHz receiver (and transmitter) on an Arduino project. I can receive the signals sent from my other Arduino very good (it sends ...
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More transmit power for 433MHz transmitter module by increasing voltage

I am using these 433MHz modules. According to the product information, I can supply the transmitter from 3-12 Volts. I am sending the data from an arduino (5V data) and want to power the transmitter ...
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230 views

433MHz sender/receiver modules share antenna

I am using a sender and a receiver for the 433MHz band, looking like these. Is it possible to share the send and receive antenna and attach one good instead of two wire antennas?
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549 views

Transmit and receive 433,92MHz signal from the smartphone [closed]

I would like to use my smartphone to send and receive signals from the devices that is working on the 433,92MHz. I assume that it's not possible to communicate directly with this device from the ...
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150 views

Thermostat bypass wiring [closed]

I'm trying to bypass the heaters thermostat of my apartment and having only a small knowledge of electronics I would like to have a some help with it. Forgive me for the ugly paint schema but I ...
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1answer
1k views

How to check a 433Mhz module on an Arduino

I am new to arduino and electronics so please bear with me :) I would like to build a 433 MHz receiver which output I would later feed to a RPi (that will be the easier part for me). I bought a set ...
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592 views

433MHz Module Antenna Ground

I have these common ebay 433 module pairs pictured below And trying to hook up external antenna. On the TX there is a little hole marked ANT which works for that. On the RX pictured (XD-RF-5V) there ...
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600 views

Can I use this rf module with HT12E and HT12D?

I have recently made RC car using HT12E and HT12D connected to a cheap ASK RF module of 433 MHz frequency,but it's range is not good only a few meters and also so prone to electrical noise generated ...
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4answers
602 views

How to reduce motor electrical noise?

I have made RC car using using ht12e and ht12d, two geared DC motors, RF module. Now my problem is that when motor starts rotating, it is generating some kind of RF signals which are interfering with ...
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1answer
230 views

Detached antenna and connecting wire length

Since my this particular question didn't get any answer, I thought of asking a more focused question, along a path which seems a bit more feasible after few tests. Is it possible to install the ...
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1answer
645 views

Transmission via RF433Hz Transmitter/Receiver pair failing AVR

I am trying to send data wirelessly through a RF433Hz receiver/transmitter pair, but nothing seems to want to work.I want to the transmitter to continuously send a number (0x81) to the receiver when I ...
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1answer
587 views

Preventing Interference when using RF transmitters and receivers

I want to use a "listen-before-talk" approach to transmit data from sensors connected to a transmitter and receiver pair to a MCU connected to a transmitter and receiver, which means that the sensor ...
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1answer
2k views

Why is 433 MHz still used?

The new RF frequencies are 868 MHz for Europe and 915 MHz for the US. I heard 433 MHz is barely regulated, read: it's chaos. Then why are 433 MHz RF modules still used? Are they cheaper to produce?
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Active 433Mhz RF tag battery life question

I am exploring the world of RTLS system and trying to produce one on my own. I chose 433Mhz frequency for its penetration capabilities and I produced a PCB mounting CC430 TI family MCU-transceiver, ...
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How do I change the frequency of an rf module?

I recently bought an AM radio transmitter/receiver from eBay. It was only after I bought it, however, that I noticed that the frequency was 315/433 MHz. I live in the UK so only 433 MHz would be ...
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1answer
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Can anyone identify this 433Mhz OOK protocol?

I am working with some wireless devices that use 433MHz OOK transmitters and receivers. They use a simple protocol for the data sent between the nodes. I feel it is reminiscent of common IR remote ...
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1answer
777 views

433Mhz Receiver

I'd like to build from scratch a 433Mhz receiver. Can anyone point me to a schematic or some material to learn how to build one? Google search didn't come up with much in the way of building one from ...
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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 ...