GEPRC Stable 12A Whoop Stack
• Chris
The GEPRC Stable 12A stack is intended as an all in one solution for toothpicks and microquadcopters.
Being an AIO, it is flight controller and ESC in one board. But this is not all - it would not be a stack without the video transmitter. The flight controller does not come with an onboard SPI receiver, so you have to provide your own receiver of choice.
Although having Whoop in it’s name, it is a way better fit for toothpick sized, micro quadcopters, especially since you need to at least power it from a 2S (up to 4S) battery.
The stack weighs in at 13.8g this is includes the AIO board, VTX with antenna and all wires.
Overview
The board comes with a pre-soldered XT30 connector to which a low ESR capacitor is attached. I always prefer the capacitor as close to the board as possible, but at least there is a capacitor provided.
One great thing about this board is, that apart from the receiver, there is no need to solder anything. This might be a great feature for people who basically want a plug and play solution for their micro quadcopter.
Unfortunately this also means that the motor plugs come pre-soldered to the board. I would have really preferred this not to be the case, but this obviously being aimed as plug and play solution, I can understand the choice.
VTX
The VTX is of the “diamond” form factor, meaning it is around half the size of the AIO board and is mounted with three of the four screws that the flight controller is mounted with.
The VTX plugs in via cable to the flight controller. Included is a cable for plugging in the camera, although this will obviously not be the right fit for all cams, you can at least either swap the plug or build an adapter with it.
The output power is switchable between 25 and 200mW. Output power and channels can be switched via IRC tramp protocol. The linear antenna is connected via U.FL connector.
The video transmitter is not being powered when plugged in via USB - you need to plug in a battery in order to power the video transmitter.
ESCs
The BLHELI_S ESC’s are capable of continuously pushing 12A, which makes them a perfect fit for all 110x sized motors, so basically all 2”, 2.5” and light weight 3” builds. The ESC’s MCU are the “better” ones, meaning you can run RPM filters via JESC.
Flight Controller
The F4 flight controller comes flashed with Betaflight 4.0.2. The target is GEPRCF411. The stock settings seem to be pretty much Betaflight defaults, which is to be expected for a stand alone stack.
Pads for a buzzer are available, but no buzzer is included - which at this size is not a big deal, since most people will probably use ESC beacon anyway to save some weight.
I would highly recommend upgrading this stack to the latest Betaflight version before usage.
Receiver options
As mentioned in the beginning, this stack does not come with a receiver, but you can basically use any external receiver you like. The board provides 5V and 3.3V. Also Uart2 is available inverted and non inverted, for both TX and RX.
Those pads are relatively easily accessible if you are somewhat experienced with soldering, this should not be a problem at all.
Accessories
In the box you will also receive a couple of screws and rubber grommets for mounting the stack. The screws - intended to mount the stack to a whoop frame - are a bit short in my opinion.
There are two sets of M2 screws - one short set that holds the stack together in the package and one longer set to actually mount the stack to a frame.
Conclusion
If you are looking for a solid stack, which is easy to use and mostly plug and play, this is a really good choice. A price of around 55$ on banggood is totally fair in my opinion, considering you get an AIO board and a video transmitter.
As mentioned in the beginning, I would not recommend this stack for a whoop though - I think a better choice would be something where you can direct solder, have a smaller VTX and thus save a substantial amount of weight.
Chris is a Vienna based software developer. In his spare time he enjoys reviewing tech gear, ripping quads of all sizes and making stuff.
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