Electronic – 433 Mhz + Attiny85 improve range

433mhzattinytransistorsvoltage-regulator

I want to send information from my Attiny85 to my Raspberry.
For the moment.
Attiny and Emitter work on 5V
Emitter have a 433 Mhz 1/2 waveform antenna 433 Mhz 1/2 waveform antenna
I'am using virtual wire

Raspberry receiver work on 5V with 430 ohm resistance for data.
I use vw.py python program

All this work fine 0-1 meter, badly (10%) at 2 meters and not at all more far away.
Problem, my desk is about 4m far away the Emitter. How can I improve this range ?

My idea : Using 12v input for emitter with 7805 for Attiny and a low cost NPN transistor between Attiny data pin, 12v and data of emitter.

Is my idea good ?
Do you have other idea ?

Thanks

Best Answer

I tried those antennae and I got better range with a whip antenna made from 17cm of copper wire. Probably 1/3 to 1/2 better. Like you I'm combining an ATTiny85 and 433mhz transmitter. The transmitter definitely works better with 12V though it works quite well on 4.5V with good line of sight over about 40m for me. When I tried a 7085 in my circuit the 12v battery did not last many hours (about 6? I left it overnight and it was dead in the morning). I did not use an NPN, I just connected the data from the transmitter to one of the ATTiny pins. It worked fine except for the battery drain which I am still trying to solve.

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