Review on Wireless 433MHz RF Module Receiver With 4 Channel Output – QIACHIP RX480E (20 Pcs) by Mike Roberts

The modules I'm reviewing right now are very good, but most of the cheap 433 MHz transmitter/ receiver pairs you see advertised aren't a good deal, because they require a digital encoder chip on the transmitter side and a digital decoder chip on the receiver side. Or, you need a microcontroller on both ends to make them work. Either way, you can't use them unless you build a circuit board to hold the extra components. The sellers never bother to tell you that additional components are needed to make those modules work. One pair that I purchased and tested (not the pair I'm reviewing here) has a big round metal can on the transmitter board. It was only when I tried to use those units that I discovered they were not stand-alone modules. I didn't want to bother ordering the encoder and decoder chips and then spend time building circuit boards for the modules, so I never used them. Those units were so cheap that they weren't worth the cost of shipping them back, so they ended up in my junk box. A product you don't use is not a bargain at any price.Just to be clear, the QIACHIP transmitter and receiver modules I'm reviewing here do not need any extra components to work and should not to be confused with the units I just described. I wanted to point out how these modules are superior to the modules that require support chips to work. These QIACHIP modules are about the same price as the other 433 MHz units, but you get a completely self-contained, four channel transmitter/ receiver pair with these modules that can be used independently, without the need for either a microcontroller, or encoder/decoder chips. However, if you want to add remote control to a microcontroller project, then the pins on this receiver can be plugged directly into a Arduino UNO without the need for any other interface components. I use digital pins 8 through 13 plus GND on the UNO. Just remember to set digital pin 13 high in your code to supply 5 Volts to the receiver. These units also have very good range. The little coil antennas are included, but you have to solder them to the boards. However, you many not need the antennas. I haven't tested the maximum range with the antennas attached, but these little units reach all over my house without the antennas. The instructions are confusing at first, because the receiver has three different operating modes, but the modules are easy to pair and program after you figure out how.Now, for that "one little catch". The only complaint I have about these modules is there is no logical correlation between the numbering of the channel selection pins on the transmitter and the labels of the digital output channels on the receiver. I was only able to figure it out by trial and error. The transmitter module's channel selection pins are numbered 1 to 4 and the receiver's four digital channel output pins are labeled D0 through D3. You'd think transmitter pin 4 would correspond to receiver output pin D3, because the receiver channels start at D0 and the transmitter channel pins start at 1. But, in addition to the offset, the numbering systems on the modules are also reversed. In other words, D0 on the transmitter does not correspond to pin 1 on the transmitter. Just when you think you have it figured out, you discover that receiver pins D0 and D1 are reversed within the bigger reversal. It's such a mess that if you're using these units in a stand-alone configuration, then you'll need to make up a table to keep the channel relationships between transmitter and receiver straight. And, if you're using these units with a microcontroller, then you'll have to sort it out in your code and hope the next pair you buy doesn't have the channel's scrambled around in a different way that will force you to modify your software. At first, I assumed the problem was unique to the first transmitter/receiver set I purchased, but I purchased a second set later and it had the channels scrambled in exactly the same way. If it wasn't for the illogical channel number relationships between the transmitter and receiver modules then, these modules would get five stars from me, because other than this they are a terrific bargain for the price.