The Bick’s MultiView Duo is a small camera switcher using either PWM from radio receiver, or signal from an FC. We will discuss the advantages and disadvantages compared to the good old Hobbyking video switcher.
Where to Buy?
Advantages of MultiView Duo Switcher
- It’s really tiny (10x17mm) and extremely light weight (0,9g)
- Very easy to solder with the well-sized solder pads
- It can be controlled by PWM signal from a radio receiver, or flight controller using PINIO feature in Betaflight
- Supports wide input voltage (4.2V – 30V), works on 5V, as well as 2S to 6S directly LiPo input
- Camera switching is very fast – almost feels like it’s faster than the Hobbyking one by a fraction of a second?
Why Hobbyking’s Video Switcher?
There are areas the Hobbyking’s Video Switcher does better.
- If you need 3 camera inputs, then the Hobbyking one is the way to go. However, I came up with a “hack” – you can hook up two Multiview DUO to achieve this, I will explain at the end of this review
- It has servo header pins, if you don’t like soldering and prefer “plug and play”, it’s much easier
Before Connecting, Beware Of…
… the BATT pads on both sides of the board are interconnected, as well as the GND pads. This means the power to the camera switcher are shared with the cameras if you are powering them off the switcher.
You only need to connect power input on one side, connecting two different power sources might create a short if the voltages are different. Make sure you are using a voltage that your camera can take.
The camera switcher is always in PWM mode by default. But if a PWM signal is not detected within 5 seconds after powering up, the camera switcher will enter digital mode (PINIO).
Connection and Usage
Connecting to a PWM radio receiver is easy, so I won’t go into too much detail. LOW PWM (< 1500) enables input 1, Hight PWM (> 1500) enables input2.
The beauty of the Bick’s camera switcher is the ability of taking digital signal.
We mostly use tiny SBUS radio receivers in our mini quads, and they lack PWM channel outputs. Being able to control the camera switcher through the flight controller is just amazing.
It works by using a feature called PINIO in Betaflight. It’s quite a confusing feature, and not very well documented, but don’t worry, it only takes a couple of CLI commands to setup :)
Setting Up PINIO for Camera Switcher
The setup is explained very well in the official manual.
Basically, you need to find a spare UART, and remap the TX pin to PINIO. If you are unfamiliar with Betaflight Resource Remapping, see my tutorial.
For example, if UART 4 is free on my FC, I first need to free up the TX pin (A00 in this example);
resource SERIAL_TX 4 None
Then reassign that pin to a PinIO resource.
resource PINIO 1 A00 set pinio_box = 40,-1,-1,-1 save
Don’t worry at all about what these lines mean, just enter them and it will just work :)
You should now see a new slider in the Modes tab labelled “User1”. You can now assign an AUX channel on your radio (a switch) to control the MultiView Camera Switcher :)
This is my wiring for the setup. I am powering everything with 5V from the FC. PWM pad is connected to TX4 on the FC. Any spare UART would do.
How to Switch Between Three Cameras? Or More?
It’s not officially recommended, just a hack I came up with recently. I haven’t actually tried it myself, but it should work :) The cool thing is you can still control it through the flight controller.
I did check with Bick’s, and he replied: “Yeah that seems like it would work. The MultiViews have a very small amount of internal resistance, so i’d imagine it would take quite a few of them to create any noticeable drop in signal strength.”
First of all, you need two spare UART’s on the FC. Get their pin numbers in the CLI resources, In our example, the pin numbers are A00 and C06. Free them up.
Now create two PINIO with the following CLI commands:
set pinio_box = 40,41,-1,-1 resource PINIO 1 A00 resource PINIO 2 C06 save
You should now see “User1” and “User2” in the Mode’s tab in Betaflight Configurator.
in the Mode’s tab, assign the same 3-position switch to both User1 and User2, with 2nd and 3rd position respectively.
Then connect the cameras and switchers like so:
I think with this technique, you can do up to five cameras using 4 camera switchers. That’s because you are only allowed to setup 4 PINIO, if you haven’t run out of serial port already.