On this page I will be reviewing the Happymodel VMR40 Mobile Video Receiver. On 5.8GHz, real time video feedback is great, but it needs to be equipped with with a receiver that is able to read 5.8GHz. This means that you cannot view videos on a smartphone or tablet. To solve this problem, the Happymodel VMR40 captures the 5.8GHz signal and converts it so that you can view it on a device which is compatible with Android and mobile tablets and the TV.
How Does It Work?
The VMR40 has a metal casing that is 4 x 6 x 1 cm (not including the antenna.) It is light as it only weighs 44.6 grams. It comes with a RP-SMA fungus antenna, a micro-USB and a micro-USB connector. To operate this thing is easy. You simply install the CameraFI software and then plug in the micro-USB cable from your tablet and connect it to the VMR40. The receiver is 5.8GHz and captures the broadcasted image. It then transcodes the image and sends it to be viewed on the USB device. This in theory is great for racers where you can see clear images on your race on your tablet in widescreen. Now lets put this theory to the test and see how good (or bad) the VMR40 actually is…
How Good Is The Happymodel VMR40?
The VMR40 needs to be powered to operate. It needs at least 5V. If your android device is capable of providing 5V via the USB connector then this is the perfect situation. The VMR40 turns on and is ready to capture images. But otherwise the OLED display housing will remain hopelessly turned off if it does not have this power supply. Indeed, even if this is true, not all hope is lost. The VMR40 housing has extra sockets that allow for an easy connection of a 2S or 3S battery. The OLED display will light up if you connect these batteries and will display the same voltage that would have been supplied by your Android device. During my tests, an old HTC One Mini had enough power to fuel the VMR40. However more recent tablets such as the Teclast tablet only provided 1.28V, which is no where near enough power to operate the VMR40. If this happens to you then you will need to get some extra batteries to power this machine.
The OLED display
The screen on this thing is rather small. To control the interface you mush spin a wheel on the right side of the housing. The small small screen requires a good eye to read it since the text and numbers are all crunched up together. However, the screen is very easy to read in direct sunlight which is a plus. The screen does the following things. ON the left it indicates the external voltage input. On the right it shows the voltage of the USB connector. It also shows the quality of the 5.8GHz reception and the name of the frequency. To run a channel scan simply press the dial and hold it and it will scan all 40 channels. However, I found these channel scans rather unsuccessful. Most of them resulted in an error saying 0 CH have been detected. Is this an RSSI problem? I’m not sure. Nevertheless, the device is compatible with most 5.8 GHz frequencies including Raceband by ImmersionRC.
The image quality is very good. The latency varies between 90 and 110 milliseconds. Its not great but is better than WIFI. The number of frames per second is 30 according to the documentation, but to my surprise it is clearly closer to 60 than to 30. However, this high quality image only lasts when the ground or trees don’t move much. For example, if you were very high up in the air, the ground would appear to move very slowly and therefore you would have a high quality image. However, when you fly low to the ground or accelerate, compression kicks in and just ruins the quality of the video! Initially, the pixels become too large, but then the pixels cluster and fill the screen and this ends with green and red stripes across the screen. This issue is visible on a small screen, but on a big tablet, the problem is merely amplified. Take a look at the photos below to see what I mean.
The CameraFI application allows you to record video on the Android device. The result is a 640 x 480 pixel video. This a low resolution video but is okay for FPV video recording. However, As soon as you pick up speed, the video quality seems to become less and less good. To be honest, the change in video quality isn’t that bad and therefore I can see myself using this to record FPV flights.
So what is the accessory for? In my opinion, this is for FPV racers who want to keep track of their FPV races. The CameraFI live app is free meaning you can broadcast video live onto Youtube and Facebook. Even if the quality is a little poor in places, I think that this is a nice feature to have. Here is an example video.
Should you buy the Happymodel VMR40?
No. I do not recommend this for capturing video on your quad. The video compression is far to really produce a decent high quality image. Also, the owners of iOS devices wont even be able to use this since it is not compatible. So, whilst he Happymodel VMR40 is a nice idea, the reality is that it doesn’t work. Nevertheless, you can get one here from HobbyKing.