FPV (First Person View) is one thing that excites almost every RC hobbyist, whether a beginner or veteran. I belong to the former category, and hence decided to explore the FPV scene without burning a hole in the pocket.
With that came selecting a nice and affordable 5.8GHz AV receiver. I did my research across multiple online stores and forums and realized that there are way too many receivers in the market ranging from as low as $10 and all the way upto a couple of hundred dollars. The $10 ones, of course, got my interest. It was a Boscam RX5808 8 channel module.
However, there was a lot of DIY-ing needed to get it working which included soldering DIP switches, antenna jack, buying an antenna, power supply port, video out jack, etc. This was definitely a waste of time for something that only supported 8 channels (although there are hacks to unlock all the 40 channels).
And then I came across the Eachine RC832 receiver (also from Boscam) which is sold by different OEMs like Eachine, Skyzone, etc. This one has all the flaws of the RX5808 ironed out. The Eachine receiver supports only 32 channel while other manufacturers have unlocked it to support 40 channels including racebands.
Oh, and it only costs $15! So I ordered one of those receivers and today we will be doing the unboxing and teardown of the same. So lets get started!
Eachine RC832 FPV Receiver Unboxing
The Eachine RC832 comes in a nice little box with a clear sticker covering the 32 channel support since it has been unlocked to do 40. The back of the packaging has the details of all the channels and frequency group available on the receiver.
Sliding open the box, we are greeted by the RC832 itself. Hiding below it are all the three accessories that you would need to get started – 1 x 5.8GHz Antenna, 1x 2.5mm male to composite audio/video cable, DC input cable with JST connector. You will need to power the receiver with a 12V DC source that can deliver at least 0.3A current.
The Eachine RC832 has an all-metal body which should help with heat dissipation. It is fairly easy to get started with and control it as it only has two buttons to jump between frequency groups 1,2,3,4 and 5 with each group having 8 channels.
Group 5 consists of the Raceband channels. A bright red 2 digit seven-segment display shows the frequency group and channels in the order fr-ch. The top edge of the receiver consists of the standard SMA antenna jack. On the bottom side there exists the 12Volt DC input port accompanied by two AV out ports which can be used for simultaneous FPViewing from one port and recording on the other.
Since I don’t have Vtx at hand currently, I will save the testing of this receiver for a future post. Now, that the unboxing is done, lets get our hands dirty and start with the tear down of the receiver.
Eachine RC832 FPV Receiver Teardown
The metallic shell of the receiver is held in place by four standard Phillips screws on the top and bottom edges. Unscrewing them and unthreading the nut that holds the SMA jack in place gives us access to the internals of this receiver.
Once the shell is removed, we are left with a single PCB that has all the components embedded in place. The rear of the PCB is completely unused.
The rectangular steel on the right top is the core of this receiver, which is Boscam’s RC832 module. The steel casing helps it with thermal dissipation and has a lot of SMD components hiding beneath it. Since this is a 40ch receiver, there’s not much left to mod in there other than hacking it with a microcontroller to tune for frequencies automatically. We will save that for another day since I don’t want to wreck this before even testing with a Vtx.
The lines from 12V port go straight to a chip labeled as 78M05LGI. This is a 5V positive voltage regulator which converts the 12V supply into 5V. A couple of capacitors and resistors ensure that the regulation is smooth. It also limits current drawing in to a maximum of 0.5A to prevent further damage in case of a short.
Right below the seven segment display, lies another chip labeled as 74HC164D. Although Google wasn’t of much help, but since its pins were directly in contact with resistors whose other ends were soldered to the display, its easy to guess that this probably is a seven segment driver IC which converts BCD or Hex into seven-segment understandable signal.
On the left side of the seven segment display is another IC which strangely has its labels sanded off and covered with a layer of hard glue. Probably the manufacturers didn’t want us to know more about it?
However, a wild guess would suggest that this is some sort of an interfacing chip between Boscam’s RC832 module and the microcontroller module which we are going to see next.
The last piece of this teardown puzzle ends with the ATMEL168 microcontroller. This tiny piece of silicon is responsible for registering the button presses into a 3-bit high/low signal to toggle between 8 channels of each frequency group. It also toggles between the frequency groups and even sends signals to the seven segment display to output the right data to the user.
Stay tuned for the working of this receiver and probably some future hacks.