A big thanks to Bang Good for providing me the sample for reviewing.
This review is written by Rob Thomson from openrcforums.com
Whats in the box:
- S8R Receiver
Double Sided Mounting Tape
Product Specification & Overview
- S8R (8CH/16CH receiver with built-in 3-axis gyro and 3-axis acceleration)
46.47x26.78x14.12mm(L x W x H)
Number of Channels: 16CH (1-8ch from conventional channel output, 1-16ch from SBUS port)
With RSSI PWM output on board: PWM voltage output (0~3.3V), 100HZ, 1500±500us
Operating Voltage Range: 4.0~10V
Operating Range: full range
Gyroscope Measurement Range ±2000dps
Accelerometer Measurement Range: ±4g
Compability: Frsky Taranis X9D Plus/X9E/Horus X12S/XJT in D16 mode
My plan is to install it in a Wingnetic flying wing – a good test model as its robust, quick and nimble.
I chose to bind the receiver up to my Frsky Horus. This process proved to be relatively painless.
My receiver did not have any indication of what firmware was installed so I simply went ahead and tried to bind in D16 mode. This did not work.
5 minutes later I had downloaded the latest firmware from:
http://www.frsky-rc.com/download/view.p ... rmware-S8R
and reflashed the firmware to the LBT mode used on my EU radio.
Success. The receiver bound as expected. Happy days.
Looking at the S8R manual it became apparent that it would be important to setup my channel orders correctly for the stabiliser function to work as expected. The receiver expects the channels mixers to be sent in the following order:
- CH1: AILERON 1
CH5: AILERON 2
CH6: ELEVATOR 2
CH9: GYRO GAIN
CH10: 3 POS FLIGHT MODE
CH11: 3 POS FLIGHT MODE
At this point, I jiggled the receiver to see if stabilisation was active. Nothing. No servo movement occurred so I concluded that with CH10 & CH11 outputting a signal round 1500ms that the stabiliser was turned off.
The receiver supports a comprehensive range of flight modes that are set using two 3 position switches.
- Stabilisation (CH10 SWITCH DOWN, CH11 SWITCH MID)
Auto Level (CH10 SWITCH DOWN, CH11 SWITCH DOWN)
Hover (CH10 SWITCH DOWN, CH11 SWITCH UP)
Knife Edge (CH10 SWITCH UP, CH11 SWITCH MID)
Off CH10 SWITCH MID)
As an curve ball – there is no easy way to tell what flight mode the receiver is in – so you need to check very carefully to make sure your setup is correct prior to flying.
Note: I will be suggesting to the opentx team that a lua widget or similar is created to automatically show the receivers flight mode on the horus/Taranis display.
Configuration of Stability functions
One of the great things about the S8R is that you can remotely configure it by using either the STK adapter on yoru PC, or a LUA script on the radio. So no need to try get at the stabiliser when its buried inside your model!
I started by configuring the receiver using the STK adapter from my PC.
Unfortunately, I did not have much success with this. I found the PC interface worked – but to be very sluggish. I was not clear at any point if it was actually talking to the receiver at all! That being said – it is entirely possible that I had a driver issue. I did not spend any time trying to debug this and moved straight on to using the LUA scripts.
Included by default on the opentx sdcard is a folder called S6R. While not specifically for the S8R, it is identical and works to configure the receiver.
This process proved to be painless. I executed the lua script and immediately was presented with a 3 step wizard to help me setup the receiver.
As can be seen in the screen shots above this is very self-explanatory and should not cause any confusion to a seasoned rc pilot.
The ability to configure the receiver from the radio is fantastic. This makes setup at the field an absolute breeze.
Issues & Problems
During setup I had a couple of issues. Some I resolved – Some I just skipped over and worked around.
- Stabilise Mode would not work: This was very confusing at first. I simply could not get the stabilised mode to enable. All the others worked – but not this one. I eventually worked out that I needed to setup a mix on CH9 for gain control. I assume that opentx was sending no data on this channel by default – so the flight control software would not enable. I assigned CH9 to a POT.
LUA script RX/Orientation: The lua script allows you to set the receiver orientation in the model. No mater what I did I could not get the receiver to pick up this change, despite it saving to to the radio. I suspect maybe a script issue or firmware issue. It is likely that I had the desktop pc app talking I could have fixed it. Regardless I simply skipped over the problem and changed the way I was locating my receiver.
I spent an hour today flying my wingnetic with the S8R receiver/stabiliser installed.
As expected - no real vices.
- Stabilise mode works great - Super smooth. The ability to dial in the gain using a slider is a winner!
Auto Level - well. it works. bit boring on the wingnetic so I wont be using it again!
Hover/Prop hang - it does a reasonable job on the wingnetic. But with no rudder on the model it tends to fall out on the yaw access
Knife edge - i did not try. without the rudder on the model their would have been no point.
The receiver can be purchased from all good frsky distributors. I received mine from Bang Good. Their individual product pages are shown below.
http://www.banggood.com/search/frsky-s8 ... =hehuishan
http://www.banggood.com/search/frsky-st ... =hehuishan
I am really happy with the receiver. It does more than I want it to do. I would certainly consider getting another for my next model.