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Low Cost Telemetry Receiver?

FrSky are gradually making things a bit difficult for the modeller on a budget. They are gradually trying to force users down a proprietary route despite the fact they made their name promoting an open system!

This means that it is becoming more and more difficult to find low cost receivers which can still bind with FrSky transmitters, especially if you have followed the FrSky firmware updates lately!

FrSky do at least offer a sensible telemetry system with their SBus telemetry port. However, there are no low cost receivers from other manufacturers that support SBus telemetry. At least one has tried but strangely they are no longer available. You are forced to use FrSky receivers if you want telemetry.

FrSky’s continuing drive towards a proprietary system has meant that modellers have started looking at systems from other suppliers.

Many, like myself, have moved in the Jumper / Radiomaster direction. These systems use a multi-module board and therefore they are able to use receivers from a variety of manufacturers. They also use OpenTX which means that users of the Taranis transmitter should feel at home pretty quickly.

I began to wonder if there was a low cost receiver from another manufacture which could be used with the Jumper / Radiomaster Tx and would give access to a low cost telemetry system. I think I may have found it!

The re-birth of my RC interest a few years ago was prompted by a very low cost Tx /Rx combination from a company called FlySky. (Not to be confused with FrSky!) They have been quietly producing systems for some time in the shadow of FrSky. FlySky have developed their own telemetry system, similar to, but not compatible with the FrSky system. One of their receivers caught my eye recently - the FlySky FS-iA6B. So I bought one!

It cost me £13.57 from Banggood. As soon as it was delivered I saw that it was now available from Banggood for £11.82 with free shipping from China!

Now, I’ve been buying low cost receivers for some time and I’m used to the flimsy cardboard covers they usually come with. The FS-iA6B is in a different league! It is packaged in a sturdy plastic box which looks like it will survive the heaviest of ‘landings’. The case is held together with two screws, not the flimsy plastic clips which tend to break at the first rough handling. The case size is 46 x 26 x 15mm. so it’s probably not going to fit in to small models easily. You could remove the box to make it smaller I suppose!

It is a full 6 channel Rx, but it has a seventh connector for binding (it uses a binding ‘loop’) and power input or output. Channel 1 can be used for PPM output if that’s your thing!

It has two aerials which are supported by small rubber grommets as they enter the case.

The main advantage over other low cost receivers, besides its construction, is that it has an i-Bus connector! This is the link to the range of telemetry sensors which FlySky has developed.

So, I’m impressed with the quality of its construction and the telemetry possibilities, but does it work with my Jumper T16?

I set up a test model on my Jumper and went to the ‘Model Setup’ page and down to the ‘Internal RF’ section.

Just for completeness, I’m using a Jumper T16 with firmware version 2.3.13 and module firmware V1.3.1.77AETR

Under ‘Mode’ I went to the receiver name and searched through until I found ‘FlSky2A PWM,IBUS’ which seemed to match the receiver, although it was a bit of guesswork at this stage. It had to be guesswork because there are no instructions with the Rx!

I connected the binding loop to the bind connector and then powered up the Rx. A red LED kept flashing.

I selected ‘Bind’ on the Tx and almost immediately the LED on the Rx stopped flashing! I removed the power and the bind plug and the TX said ‘Telemetry lost’, which I thought was a good sign!

I connected a couple of servos to the appropriate connectors on the Rx and powered it up again. The two servos worked perfectly!

I went to the ‘Telemetry’ page on the Tx and made it search for sensors. You can see in the photo which sensors it found. This is without anything plugged in to the i-Bus port!

I can’t test the i-Bus port because I haven’t got anything to plug in to it! I have just ordered an altitude sensor (£8.25 from Banggood  - with free shipping!) so I’ll report how it works later.

I also haven’t yet gone to the field to do a range check, but I’m confident that there won’t be an issue. The information on the Banggood site says that the range is in excess of 500m

I’ll do a further report on this receiver when I’ve installed it in a model with the altitude sensor - when it comes!  Until then I’ve listed what I think are the pros and cons of what I’ve found out so far:


Low cost.

High quality construction

Telemetry (Yet to be fully confirmed!)

Compatible with Jumper / Radiomaster


No instructions!


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So - an update on my experimentation with the FS-iA6B.

First a slight negative!

I showed in my first report that the FS-iA6B outputs some telemetry to the Jumper T16 without any telemetry modules plugged in. One of the sensors shown was the classic A1. Unfortunately this sensor shows the receiver voltage and is showing 5.01v in the photo above. If you are powering the Rx with an ESC then this is about as useful as a chocolate fireguard! It will be 5v until the lipo is as empty as a politician's promise! It would have been much more useful to show an external voltage like the full lipo voltage. But it doesn't! Someone on the internet has shown how the FS-iA6B can be modified to read an external voltage, but as this involves cutting some tracks on the PCB inside the Rx and then soldering on a new connection, it's for the strong willed, skilled technician with a sharp soldering iron and deep pockets! Ask me how I know!

So, the only official way to read lipo voltage is to buy the FS-CVT01  voltage sensor. Amazon sell them for £18.99 which is an absolute rip-off as they are available from a number of sources for about £8 - £9. Hobbyking sell then under the 'Turnigy' name as TGY-CVT01 for £2.99! I bought one from Banggood for £7.23  before I saw the Hobbyking price!

It plugged in to the FS-iA6B  i-Bus port and it immediately showed a sensor called 'A3' which after a quick check I can confirm that it is the voltage connected to two flying leads from the FS-CVT01.

I also bought a FS-CAT01, which is the FlySky altitude sensor. The sensors simply daisy chain together and once again I can confirm that it just works. I don't mean it only just works, I mean that it works without any effort!

Interestingly, Amazon sell this one for £11.33, Banggood for £8.09 but Hobbyking don't seem to be selling it currently!

The downside to this sensor is that it doesn't show vertical speed as an output. Instead it shows altitude, pressure and temperature which is nice, but to get the Vario option working under OpenTx we need VSpd! I'm working on it! More later!

For what it's worth I've attached a picture of the FS-iA6B with its two sensors plugged in!

My next step is a full range check with this receiver and then install it in a model. I have no doubt that it will have suitable range but it would be sensible to do a proper check. I'm also working on a LUA script for VSpd!

At the moment - very encouraging!

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VSpd for the FlySky receiver!

I can now confirm that I have finished the LUA code for a Custom Script which installs a new sensor in to OpenTx which shows vertical speed (VSpd) data calculated from the 'Alt' readings available from the FS-CAT01 sensor. It sounds more complicated than it is! Basically the user will be able to use VSpd in the same way on the FlySky system as on the FrSky system. The 'Vario' settings in OpenTX will work the same way in both systems.

I've also written a full installation guide.

I haven't yet tested it on a model, but it bleeps when I move the Flysky sensor up or down so it's looking good!

Let me know if you are interested in having a go yourself! Obviously you will need a FS-iA6B and a FS-CAT01, but at these prices it's worth a try !

I've just noticed that Hobbyking are selling their version of the FS-iA6B which they call the Turnigy TGY-iA6B V2  for £8.99. As always Hobbyking will add some delivery charges on to this, but even so that's a ridiculous price!

Details at :

Turnigy TGY-iA6B V2 Receiver 6CH 2.4G AFHDS 2A Telemetry Receiver w/SBUS

Just a couple of minor updates!

I took my FS-iA6B up to the field last Wednesday and did a range check. It wasn't installed in a model at this stage, just lying on a table near the cars with a Lipo, ESC and a servo attached.

I put my Jumper T16 in to range check mode and started walking towards the take off area.

By the time I reached the take off area the FS-iA6B was still driving the servo properly ( I had an accomplice to check this!) and the T16 was showing an RSSI level around the 50 - 60 range. I think it's fair to say that this is the best range check I have ever had with any receiver including FrSky! My analysis is that there is no issue about range with the FS-iA6B!

I have been looking at prices for the FS-iA6B and I've mentioned some above. However, the best I have seen is from AliBaba in China. I haven't bought anything from AliBaba before, so I thought I would test them out. So I have sent them an order for six FS-iA6Bs. The full cost for each receiver including delivery turned out to be about £8. I will have some spare when I have used the ones I want, so let me know if you want one! It will cost you £10. After all it was me who took the risk in the first place!

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