This review is of the original RROSD Pro. You may also be interested in my RROSD Pro V2 Review.
Pic: RedRotor RC
The RedRotor RROSD Pro is a combined power distribution board (PDB) and on-screen display (OSD). The OSD is a stand-alone unit that does not require any connection to the flight controller to function, since all the measurements are made by the RROSD itself. It does, however, provide a 5V output (max 250 mA) that can be used to power a flight controller.
The RROSD is simple to install – just connect the battery input, the ESC power leads, the FPV camera and video transmitter. However because there is only one positive and one negative pad for ESC power, wiring is less clean than it would be if there were two sets of ESC power pads, one on either side of the PCB. The picture below shows my ESC power wiring, which all has to come to the same side of the Krieger pod.
Once installed, setup is easy using a button on the PCB that can be used to switch between NTSC and PAL modes and navigate through an on-screen setup menu.This allows you to calibrate the voltage, current sensors and RSSI sensors, and put a gray box behind the OSD text for improved OSD readability if you want to. You can also set the number of mAh at which the mAh figure will start flashing to warn you that you approaching your battery capacity, which I find a very useful feature (although perhaps less so if you fly with many different battery pack sizes since it would need to be reconfigured each time).
Because the OSD is stand-alone, the display is limited to flight time, battery voltage, current, and mAh consumed. RSSI can also be displayed if you connect a FRSky PPM or analog (DC voltage) RSSI input from your receiver. And if your quad is equipped with the custom RedRotor IR lap timer transponder it can also display a lap counter, lap time and fastest lap time. The software automatically configures the display depending on what is connected, displaying the various parameters in one or two lines at the bottom of the screen. You can’t manually adjust the layout of the OSD – it displays what it wants to display, where it wants to display it. The picture below shows how the OSD information appears at the bottom of my display (the grey bar behind the text can be turned off). FromĀ left to right: battery voltage, flight time, current consumption, mAh used. I don’t have RSSI or the IR lap counter. In general I found the layout to be very readable – my only criticism is that the mAh figure can be hard to read; a space between the figure and the “MAH” text would help.
RROSD Pro Display
The RROSD PRO provides 12V, 5V and raw battery voltage outputs that can be used in various combinations to power the flight controller, FPV camera and VTX. It also has a buzzer output that can be used to activate a lost model alarm when RSSI indicates signal loss for a period of time.
I found that when running with 4S batteries, with the VTX and camera both connected to the 12V supply, the RROSD provided effective filtering giving me clear video. However when I tried to run off 3S batteries, setting the power jumpers for 5V to the video camera and raw battery voltage to the VTX, my video was almost unusable due to banding when the motors were running any faster than idle. This indicates that when “raw” power is selected for the VTX, the battery power is not adequately filtered. In any case, since changing the camera and VTX power connections requires soldering a jumper, this would not be a usable solution for someone who wanted to fly both 3S and 4S. I also tried connecting the VTX to the 12V supply while running on a 3S battery, but this did not work either. It would be better if manufacturers could provide an output that auto-switches between raw battery voltage and regulated 12V depending on the battery voltage, and that provides adequate filtering in both configurations.
The other problem that I had was that the RROSD lost video synchronization when connected to the Foxeer XAT 1200M 16:9 FPV camera. However since I have seen reports of this when using the XAT1200M with other OSDs I am inclined to blame the camera not the RROSD Pro.
Overall the RROSD Pro is easy to use and provides the essential information required by a racing/freestyle miniquad pilot. It’s especially nice to see the mAH used, and to be able to set a warning when it reaches a preset level, since this is the best indication of how much charge remains in the battery. Unfortunately the inadequate raw battery filtering makes it unusable when running off a 3S battery unless you install external filtering.
Postscript
Since I wrote the original review, RedRotor has released RROSD Pro V2. This seems to fix a couple of issues I had with the board:
- It has four pairs of positive and negative ESC power pads in the corners of the board, rather than only one positive and one negative power supply pad. This will make wiring much neater.
- The VTX and camera now have the option of a 10V supply voltage, instead of 12V. I hope this means that the V2 board has a regulator that can work down to 11V or so, allowing 3S and 4S batteries to be used without having to change a solder jumper setting, and that this 10V output is adequately filtered to prevent video lines.
- The maximum current has been increased to 150W – perfect for the F60 motors I’m planning in my next build….
Here’s a picture of the V2 board:
Pic: RedRotor RC
If the 10V supply is clean on 3S power, then RROSD PRO will remain my preferred means of painlessly adding OSD to miniquads. I have one on order and will post a review when I receive it!