Poor 433MHz receiver range [FIXED]

Share your Projects!
1

I have the cheapo version with no crystal like this:

Image result for 433mhz receiver

I decided I wanted to use it to sniff my doorbell (also 433MHz) and possibly do something with it. However, I found that the range of this thing is not very good. So, I added a whip. It improved the range to about 5 meters but I wanted more.

I tried different variations of an antenna: coiled, straight, long, short but couldn’t see any more improvements. Frustrated, I placed an order for a super heterodyne receiver. But, I’m impatient so I decided to fiddle one more time with the cheap receiver that I have.

I first determined the distance where I know I’m within the range of my transmitter but also one step away from losing reception. Toggled my etekcity switch to force the transmitter to send something and I see something on my receiver as expected. One step back, did the same toggle, nothing.

Here’s the fix. I Slowly turned the screw of the coil counter clockwise, toggled the switch, BAM! it worked! I slowly walked away while toggling the etekcity switch and it’s still working. At this point, I’m already about 20m away from the transmitter. This is also going through walls. I’m happy and of course I cancelled my order and save myself $6.99 :slight_smile:

2 Likes
2

Nice! What Arduino and libraries are you using?

3

The transmitter module is connected to a NodeMCU while the receiver is connected to a Arduino One with an Ethernet shield. I’ll be moving this to a Wemos later now that it doesn’t have to be close to a Ethernet jack.

I wrote both Tx and Rx code from scratch based on somebody else’s code. I’ll post this on github along with the promised-still-to-be-done code for my home made light switch add-on for 3 way light control.

4

Nice! For me, this type of antenna also did wonders to the range, most notably for the transmitter though:

5

I finally pushed my code to GitHub.

I’m still in the process of refactoring and updating documentation. But feel free to ask any questions if any. I’ll try to update the receiver side when I get home later.