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Topic: 433 MHz transmitter/receiver using with RadioHead and LowPower.h? (Read 127 times) previous topic - next topic

Oniudro

Hi there,

I managed to use the cheap 433 MHz radio receiver and transmitter with 2 Arduinos. The transmitter works fine with LowPower.h, but the receiver is little bit more complicated. I tried to use pin 2 as data pin from the receiver to wake up the receiver-Arduino, but the receiver always sends some data to pin 2, even if there is no real signal sending. So the receiver-Arduino is too often awake.

Any ideas how to manage this problem? Is it possible to only wake up the Arduino when some data arrives?

The aim is to save energy because of battery operation.

Thanks!

Peter_n

Please tell us which receiver and transmitter you are using, and which LowPower.h.

This LowPower ? https://github.com/rocketscream/Low-Power

Receiver and transmitter like these ? http://www.instructables.com/id/RF-315433-MHz-Transmitter-receiver-Module-and-Ardu/

Those receivers have automatic gain. They amplify the signal, and they don't care if that is noise or real data. So everything comes out of the data pin. The VirtualWire or RadioHead library reads the noise or data, tries to identify the start pulses and tries to read the data. It even allows some noise in between the data.
That means that those receivers receive all the time, and send all the noise or data to the pin.

It is possible to go sleep and just wait for valid data, when chip is used that has the complete protocol inside the chip. They are often transceivers in a single chip.
There are many of those, see the RadioHead page and the Sparkfun guide.
http://www.airspayce.com/mikem/arduino/RadioHead/
https://www.sparkfun.com/pages/wireless_guide

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