I'm a noob who just received an Atomrc dodo, and I have a Spektrum SPM4650 receiver I need to install. The wiring diagram (below) is clear enough, but I'm new to soldering and would prefer to avoid soldering onto the tiny pads on the FC if possible.

wiring diagram

The tan box labeled RC corresponds to a 3 pin connector. The quad came with the corresponding male component of the connector, with 3 wires with exposed ends. 3 pin connector

My question is this: is this connector an alternative to soldering the receiver directly to the FC? If I solder the wires on the connector to the receiver and plug it into the FC, will the FC be able to tell which kind of receiver it is and use it? Or am I misunderstanding what this connector is?

The above image is the only documentation available from atomrc's website, which seems a bit... lacking. It's like I'm expected to already know a bunch of conventions related to these components, but I don't where I'd learn that information if not from the manufacturer.


1 Answer 1


Sorry, but soldering to tiny pads is unavoidable when building a quad, especially with a tiny 2.5" quad. (unless you buy one with the receiver already installed, and never need to replace anything)

I think that that receiver comes with solder pads and the option of adding a socket for that wire, or just soldering wires directly to the board. The web page for the receiver shows it both with and without a socket. However it has holes for fitting the socket, but the FC only has pads.

On a quad this small, plugs take up a significant amount of space, and there often just isn't room - or for enough slack wire to allow them to be disconnected. Also plugs can develop intermittent connections as they age (and as a result of crashes), so solder joints are generally preferred.

Get yourself a good soldering iron (they're a lot cheaper than they used to be) and a practice board (or just an old circuit board) and practice until you're confident. Or find someone who can do it for you.

  • $\begingroup$ Thank you for your input. As it turns out, you are correct, I had to solder to the pads. Happily, it was not as tricky as I feared and the quad is flying. (I will note the included diagram was wrong, I had to use Tx2, not Rx2. I only found this out by finding a random YT video about the receiver that mentioned this fact.) $\endgroup$
    – Harabeck
    Jul 12, 2021 at 15:26

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