Thank you so very very much.. Have been looking for this for 3 weeks now!! Finally... Although a Spektrum/Radiomaster+ELRS guy myself. I am helping with setting up a club plane with 2 QX7's. I was really disappointed that so little useful information is documented with and about frsky stuff and compatibles, espescially concerning telemetry... Battery voltage in IMHO should be build in as a standard on virtually any receiver from any brand... very grateful to you to point this out for this receiver !!
For binding from Radiomaster Tech Support: Hello, regarding your question, we have consulted the technical department for you, and the reply is as follows: Please note that the common phenomenon of the Frsky protocol is not to let the transmitter and receiver be too close together, so that the signal is very strong, which will cause a flood effect, you will feel that the signal is lost, but you do not need to re-frequency, you only need to put the receiver and the transmitter about 1m distance away from the good, if you test the aircraft closely, You can find a Low Power option in the next few lines of the transmitter's Internal RF Settings. Turning this option on will use the Low power mode, which allows you to be close to the transmitter and receiver and operate normally, but be careful to turn off the low power mode when you are out flying. This principle is like using a loudspeaker to shout to the ear, which is beyond the ability of the ear to distinguish. We also recommend that you use the FrskyX D16 protocol to bind the R88 receiver.
The signal flooding anomaly is fairly common knowledge with FrSky protocol and some others. I use the R88V2's and they work great for me. Fantastic budget receivers.
but to update the firmware of this receiver how should I do it?I can not find anything for update or changhe firmware receiver (fcc or lbt). I saw how to update firmware receiver frsky x8r with tx16s and module4in1 . with the pins of the external module (reversing + and -) and s.port . For radiomaster r88 v2 I have no idea how to update firmware. But you know official forums for help with: radiomaster tx16s mk2 max multimodule 4in1 (radiomaster) edge tx ??
I am currently not aware of any way to update the firmware on these receivers. I don't believe the standard FrSky firmware can be used but I am not certain of this. I haven't tried.
Dude ! It's absolutely brilliant! ❤ It works perfectly up to 4s👌 Have you had any feedback on the modification using the 220k resistor? Obviously it's at my own risk, but would you say it's pretty safe? I'm afraid it will work for a while, then end up getting magic smoke mid-flight. 😅 And... Did you find electrical diagrams of the R88 to deduce the procedure to follow, or did you deduce by observations of the circuit? I would really like to know where to find this diagram if it exists 😁 Thank you very much for this video, these kinds of tricks are so cool! 🙏
Thank you for the comment. Yes it works with the 220K for up to 6S (26.07vdc). I didn't have 50vdc to feed it but according to the math, if you use a 1 meg ohm resistor in series it'll handle up to 12S (50.4vdc). I can't recall where I found the diagram, if I can find it I'll share. The internal voltage divider is: [Ground - > 100K ohm - > (3.3V max signal at RX chip) < - 470K ohm < - voltage input sense wire] So you add your series resistance to the 470K ohm resistor so that whatever voltage you feed to the input cannot output more than 3.3VDC. Hope that makes sense. Plenty of voltage divider calculators online to plug the numbers into. If you do it correctly the RX chip never sees greater than 3.3vdc. Just have to adjust the ratio to calibrate the display. Note that the higher you go the lower the resolution will be to display since you are dividing a higher voltage into 3.3 for the total resolution.
@@shanesdiy A huge thank you for your ultra fast and detailed response! You are awesome 😀 It’s very informative. This also confirms my fears about the drop in resolution when increasing the division scale.. I had an idea and I would like to know if you think it is an electrically safe solution: With a Lipo 6S for example, Connect the voltage sensor wire to the second or third wire of the balance plug and only get the voltage of one or two cells! Unless you have a Lipo in poor condition there should be no significant imbalance between the cells, no? So I suppose it would be quite sufficient to set a low voltage alarm based on 3.7 or 7.4 volt. Am I wrong? Does this represent an electrical risk? The goal is to have the best resolution while remaining as simple as possible But if the cells do not discharge in a balanced way it might not actually be much more precise, or even worse.. So, Maybe just taking the voltage of 4S instead of 6 could be a good compromise..? I'm curious to know your opinion 😀 Thanks again!!!
@@nikosystem1 Decided to run another test just now. Apparently the resolution isn't really a problem, maybe it would at some very high voltage but not up to 30V. I just did a test and added a 320K resistor which should allow up to 29.37 VDC sense input (which would be about a "7S" battery). With my bench supply I was able to hit 29.3V and with the adjusted ratio it measured that fine. I then lowered the supply to 12VDC (which would never swing that far in the normal use) and the telemetry voltage only drifted off by ~0.10 vdc and I'm using 2 decimal places with my telemetry display. I would not be concerned about resolution or accuracy. I would choose the appropriate series resistor for your required max voltage and measure full battery voltage. If you didn't want any series resistor you could certainly plug it into a balance lead and scale the ratio to that. I'm thinking just do cell #1 if you do that and just watch the single cell voltage. Since you wouldn't know if all cells were balanced and wouldn't be reading full battery voltage anyway the single cell voltage would be all you'd need and would actually be easier to decipher looking at the screen. 4.2v is full and about 3.5-3.8v, or whatever you use for low, would be time to land. Even if you monitor the full pack voltage you won't really know if a single cell gets out of balance, you'll have to check that with a LiPo tester after you land.
Great job I have telemetryu in 6 receivers. I run one for 4 hours just to see if there would be a problem. None, I am right on for voltage using a multimeter as check. I have added a 4th wire to the sbus plug and I have hard wired to the positive lead of the esc. I had a little trouble when I tied to the red wire on the balance plug. Again thanks distance is great and now I have telemetry for my flight battery what else could we want. Thanks for sharing your discovery with us... I loved your video on the distance test we really got a bargain for $11 Thanks Chuck Gaydos
What a good find Shane. I will also use it on my glider. Only thing, your last comment about it destroying your radio could be true if you exceed the specified maximum input voltage of 8.4v. I would recommend not exceeding 2S battery packs. Thanks again for sharing.
Thanks for watching and or your comment. The 8.4 V limit is just the BEC voltage limit to power the receiver, the pack voltage sense input goes through a voltage divider so is perfectly safe for the receiver. After more research I've found that 18.81 volts is max wiring direct as shown here but if you add a 220K ohm resistor in series on the sense wire it will safely read up to 26.07 volts for a 6S pack. Just have to reset the ratio to scale the voltage to display properly.
Initially I wasn't exactly sure which connector size it was to add another wire to the connector. I found a kit with a large number if connectors but it had 100's and was $20-30 and soldering it was free. Since I wasn't using SBus, on another RX after this video, I pulled the SBus connector pin out and moved it over. It was pretty easy so if you don't need SBus that is an easy way to get the voltage without soldering.
Really useful and interesting. Thanks. When messing about for long periods of time either programming or testing etc on the TX16s, could it be plugged into the mains via the charging port, so it’s operational whilst charging or working of the mains so to speak, if that makes sense? Or simply a no no.
I sit and program often and I'll charge and use the radio at the same time. It will charge while powered on. I've heard people say not to but I don't know their logic behind it. My only reservation is I don't like moving the radio around while the USB cable is plugged in as I might wear out/break my USB port. I'm the same way with my cell phones, laptops, etc. though...
This trick looks like a great find so I bought an R88 and bound with the FrSky D8 protocol. I can see A2 telemetry displaying voltage, and adjusted the ratio, but my issue is when I setup my widgets to display the reading on the TX16S main screen it shows 0v, like it’s disconnected. Under the telemetry screen it shows proper voltage data. Any idea what I’m doing wrong? I can get the RxBat and RSSI Telemetry to display but not A2 (pack voltage which is all I really want).
Are you sure you are selecting the correct telemetry value? Which Widget are you using? Let me know and I'll test it to see if I get it working. Did you see my Episode 1 using the Spektrum? I think I used the same Widgets for this one, might see something helpful in that video. I assume you are on a TX16S? Which EdgeTX version and which Multi-Module firmware version?
@@shanesdiy thanks for the quick reply. Are you on RCgroups? TH-cam isn’t the best for showing my setup. I’m using a top bar widget location and running edgetx-tx16s v2.9.4 “providence”. I’m selecting Value as the widget type and choosing the Source as the “eyeball with signal” A2. It shows as such with 0.00 on the main screen but when I click Model and Telemetry A2 shows proper voltage.
@@shanesdiyI tried changing the name of A2, and used VBAT. For whatever reason this worked and solved the problem. I’m not sure why it wouldn’t work with the stock value of A2 but at least it works now on 4s reliably. Thanks.
Hello friend and thanks for this discovery. I had the r168. But now with the r88 it was no longer possible to display the voltage of the Lipo battery but with your modification it is possible why I never thought about what that x was before. question can I connect a 6 cell battery to the x connector, in your video you show that you give 15 volts and no more. thanks compliments of the channel.🤪
Someone else asked that below. 18.81 volts is max wiring direct but if you add a 220K ohm resistor inline on the sense wire it should safely read up to 26.07 volts for your 6S pack. This is because the receiver has a voltage divider circuit built in and the 220K resistor offsets the voltage the RX "sees". I haven't tested this limit myself, just learned by research and analyzing diagrams. Use at your own risk. You will, of course, need to properly calibrate the voltage as I've shown in this video to get it to read correctly.
Hi, thank you so much for replying to me. I'm Italian, I have the old r168 receivers which I really like, I set my RadioMaster tx16s with Open TX so that it talks to me when it reaches the 4s battery storage voltage, which is 14.2 volts and everything works great, Not Unfortunately I bought other receivers because I thought that the R88 v2 did not have the Vbat input as it did for the r168. But thanks to your video I noticed that the sbus connector has a fourth pin called X next to it and which can accept this voltage as input lipo, I know that there is a resistive divider inside, I had already thought about putting a resistor to attenuate the voltage value of a 6s, but I had no guarantee on this but since you also proposed it to me, for sure It works very well, obviously after some tests to be done. now I will make a purchase r88 v2 to modify it according to your instructions and if it works and if the radiomaster warns me with a voice message (model battery empty land immediately), I will be happy and I will buy others. at our airfield many have no longer bought Radiomaster receivers due to the lack of VBAT in telemetry, as soon as they find out about the change they will make hidden purchases of R88 v2. Thank you so much for giving us this gift of knowledge, you are a GENIUS. thank you thank you😀👍👌
@@hobbyfacile5342 I'm so happy you found the video useful. I also did a very extensive range test of the R88 V2 if you find that recent video. I have some more videos coming soon on another range test with some TX mods, as well as a video on the TX mods I'm doing. I may also do another video on the voltage with the added resistor to confirm it will handle the 6S voltages.
Hi friend, I am Dirk from Germany and have done the mod with the 220k resistor in series to my 6s LiPo with my R88 V2 and TX12 MK2 transmitter. It works fine and shows the right voltages that i have measured with my multimeter. From empty at around 20 V and full at around 25V my transmitter shows the exact voltages in 0.1V steps. You have to correct the values in the transmitter telemetry setup screnn like shown in the video, thats it. And thanks to shanesdiy for this great information/channel about the A2 pin at the R88 V2. That´s the thing I have missed. For about 12€ at banggood you get a receiver with RSSI, RxBt and Fl(ight)Bt telemetry data without any external sensors 😀
I decided to risk a RX with this hack. Seems to work well with 3S and 4S packs from what I've tested so far. I was hoping to uses this on a 12S model, but it doesn't register correctly at those voltages. It didn't work with 6S either. I'm far from being up to speed on basic electronics, but I'm guessing that the proper resister in the sensor wire would drop the voltage and get it back to where the output is variable, then just calibrate to the proper voltage. Any input on this would be appreciated.
18.81 volts is max wiring direct as shown here but if you add a 220K ohm resistor in series on the sense wire it will safely read up to 26.07 volts for a 6S pack. If you didn't add any series resistance when trying over 4S hopefully you didn't damage the receiver already. DO AT YOUR OWN RISK... I just did the math and if you add a 1.0 meg ohm (1,000,000) resistor in series with the voltage input this should allow it to accept up to 50.4 volts of a 12S (technically 51.8V max). Just have to reset the ratio to scale the voltage to display properly.
@@shanesdiy Thanks for the help on the resistor. I was going to spend some time today trying to figure out what resistors might be needed. I had it hooked up to 12S power and I don't think it hurt anything. No magic smoke escaped. All RX functions seem to be normal. The voltage telemetry still works at 4S power. Yes, at my own risk!
Great video thanks however, I've just tried this with a V1 R88 and it doesn't seem to work. I only show 0.0v on the A2 output. I've double checked the wiring. I repositioned the positive lead on the supplied plug to the A2 output (pin4). I plugged the positive wire into my balance lead (1,2 and 3 cell positive position). Tried to rediscover telemetry. Just shows 0.0v. I'm guessing it only works on the v2? Cheers.
I believe it is a ZH 1.5mm JST, 4 pin. I contemplated getting a kit off Amazon that has many different sizes but was hard to justify $25 for a kit when I just needed one for this project. Note, this was my best educated guess on the connector based on research and measurements so take that for what its worth... if I can find a smaller, cheaper kit or pack I'll pick it up and test.
@@robdapraia3486 I just tried pulling the white wire pin 3 out of the included ZH connector to move it to pin 4 to use for voltage telemetry and with a small sharp pick it was actually pretty easy to get out. If you don't plan to use the SBUS cable turns out it is pretty easy to move the wire in the connector. If you happen to mess up one, you have 3 tries.
This is probably a basic question, but on my Radiomaster TX16S I can bind to the R 88 receiver, but I’m not getting any RSSI numbers back. I can bind to a different receiver like Frsky X8R and get RSSI immediately as well as battery voltage. Any ideas why I cannot get that on the R 88 receiver when I bind to it?
That was it. I watched another vid on binding this specific receiver and it showed a different protocol then what I was using. Thanks again for your great vids and helpful info for all of us.
18.81 volts is max wiring direct but if you add a 220K ohm resistor inline on the sense wire it should safely read up to 26.07 volts for your 6S pack. This is because the receiver has a voltage divider circuit build in and the 220K resistor offsets the voltage the RX "sees". I haven't tested this limit myself, just learned by research and analyzing diagrams. Use at your own risk. You will, of course, need to properly calibrate the voltage as I've shown in this video to get it to read correctly.
The 4th pin is the voltage sense input wire that we used in this video. The 3rd pin is the SBus output that can be connected to a flight controller to send 16 channels of data. I believe 15 channels is direct from the transmitter, channel 16 appears to be an RSSI value in my testing but I'm not 100% certain. Is this what you mean? If not I may need more detail of what you would like to do.
On my 2nd R88 I was able to easily move the pin in the supplied connector. Used a small pick or pin and be gentle. Another commenter was also able to successfully move the pin. No soldering required!
so you are using a scope . so you are calib the telemetry to PEAK to PEAK and not RMS as i assume more telemetry sensor use . ( also lets forget about relative / average ) but without explaining this to folks with cheap multimeter you are all calibrating to whatever...
No scope was used in this video, just the variable bench power supply which I previously validated with my Fluke 87V to make sure it was "close enough". Any average multimeter or even your LiPo checker will suffice.
Hello. I got a question. I use 6 pack LiPo with R88 and TX16 as TX. I did similar setup and I get voltage reading on A2. I calibrated it for current pack volyage (for example 25.2V) but after a flight it still shows 25.2 but when I measured pack voltage with multimeter it was 23.8V. It seems like R88 did not transmit correct voltage value in real time. On another video I heard that radiomaster RX support up to 4 pack batteries. Could this be a problem? What else I can check?
Did you install the 220K ohm resistor in series with the voltage sense wire? If not, you might damage the receiver. Without additional input resistance the maximum input voltage is 18.81V. The 220K resistor added allows it to accept up to 26.07V.
@@shanesdiy Great, thanks. I will do that. Maybe this was the reason it did not show correct voltage. I also tried 5 s pack with 20V and it still showed 25.2V, so 220K resistor could solve my problem.
I just use 1/4 watt, 10% or lower resistors. There is no current going through it so it's not important. Just to clear up how the receiver monitors & scales the input sense voltage, there is an internal voltage divider. The built in resistor values for this divider are sized to only pass 3.3V (its max input limit) to the IC when 18.81V is applied to the sense wire. When you add 220K ohms to this voltage divider by placing it in series with the input wire, you change this scale to pass 3.3V to the IC when 26.07V is applied. When you sent 25.2 volts to sense wire without the added resistance, the receiver IC was potentially getting 4.42V but it can only safely take 3.3V max. There is also a current limiting resistor on the input to the IC so it may have helped save the IC input. If it will no longer read voltages properly you may have damaged it.
![[LIVE] BABYMONSTER(베이비몬스터) - DRIP | 두시탈출 컬투쇼](http://i.ytimg.com/vi/UG05pxLGwzc/mqdefault.jpg)
Thank you so very very much.. Have been looking for this for 3 weeks now!! Finally... Although a Spektrum/Radiomaster+ELRS guy myself. I am helping with setting up a club plane with 2 QX7's. I was really disappointed that so little useful information is documented with and about frsky stuff and compatibles, espescially concerning telemetry... Battery voltage in IMHO should be build in as a standard on virtually any receiver from any brand... very grateful to you to point this out for this receiver !!
For binding from Radiomaster Tech Support: Hello, regarding your question, we have consulted the technical department for you, and the reply is as follows: Please note that the common phenomenon of the Frsky protocol is not to let the transmitter and receiver be too close together, so that the signal is very strong, which will cause a flood effect, you will feel that the signal is lost, but you do not need to re-frequency, you only need to put the receiver and the transmitter about 1m distance away from the good, if you test the aircraft closely, You can find a Low Power option in the next few lines of the transmitter's Internal RF Settings. Turning this option on will use the Low power mode, which allows you to be close to the transmitter and receiver and operate normally, but be careful to turn off the low power mode when you are out flying. This principle is like using a loudspeaker to shout to the ear, which is beyond the ability of the ear to distinguish. We also recommend that you use the FrskyX D16 protocol to bind the R88 receiver.
The signal flooding anomaly is fairly common knowledge with FrSky protocol and some others. I use the R88V2's and they work great for me. Fantastic budget receivers.
THANK YOU!!!! No resistors required like frsky receivers! 😎
Up to 4S no resistors. If you want to monitor up to 6S you will need a 220K ohm resistor in series with the sense wire.
but to update the firmware of this receiver how should I do it?I can not find anything for update or changhe firmware receiver (fcc or lbt).
I saw how to update firmware receiver frsky x8r with tx16s and module4in1 .
with the pins of the external module (reversing + and -) and s.port .
For radiomaster r88 v2 I have no idea how to update firmware.
But you know official forums for help with:
radiomaster tx16s mk2 max
multimodule 4in1 (radiomaster)
edge tx
??
I am currently not aware of any way to update the firmware on these receivers. I don't believe the standard FrSky firmware can be used but I am not certain of this. I haven't tried.
Dude ! It's absolutely brilliant! ❤
It works perfectly up to 4s👌
Have you had any feedback on the modification using the 220k resistor?
Obviously it's at my own risk, but would you say it's pretty safe?
I'm afraid it will work for a while, then end up getting magic smoke mid-flight. 😅
And... Did you find electrical diagrams of the R88 to deduce the procedure to follow, or did you deduce by observations of the circuit? I would really like to know where to find this diagram if it exists 😁
Thank you very much for this video, these kinds of tricks are so cool! 🙏
Thank you for the comment. Yes it works with the 220K for up to 6S (26.07vdc). I didn't have 50vdc to feed it but according to the math, if you use a 1 meg ohm resistor in series it'll handle up to 12S (50.4vdc).
I can't recall where I found the diagram, if I can find it I'll share. The internal voltage divider is:
[Ground - > 100K ohm - > (3.3V max signal at RX chip) < - 470K ohm < - voltage input sense wire]
So you add your series resistance to the 470K ohm resistor so that whatever voltage you feed to the input cannot output more than 3.3VDC. Hope that makes sense. Plenty of voltage divider calculators online to plug the numbers into. If you do it correctly the RX chip never sees greater than 3.3vdc. Just have to adjust the ratio to calibrate the display. Note that the higher you go the lower the resolution will be to display since you are dividing a higher voltage into 3.3 for the total resolution.
@@shanesdiy A huge thank you for your ultra fast and detailed response! You are awesome 😀
It’s very informative.
This also confirms my fears about the drop in resolution when increasing the division scale..
I had an idea and I would like to know if you think it is an electrically safe solution:
With a Lipo 6S for example, Connect the voltage sensor wire to the second or third wire of the balance plug and only get the voltage of one or two cells!
Unless you have a Lipo in poor condition there should be no significant imbalance between the cells, no? So I suppose it would be quite sufficient to set a low voltage alarm based on 3.7 or 7.4 volt.
Am I wrong? Does this represent an electrical risk?
The goal is to have the best resolution while remaining as simple as possible
But if the cells do not discharge in a balanced way it might not actually be much more precise, or even worse..
So, Maybe just taking the voltage of 4S instead of 6 could be a good compromise..?
I'm curious to know your opinion 😀
Thanks again!!!
@@nikosystem1 Decided to run another test just now. Apparently the resolution isn't really a problem, maybe it would at some very high voltage but not up to 30V. I just did a test and added a 320K resistor which should allow up to 29.37 VDC sense input (which would be about a "7S" battery). With my bench supply I was able to hit 29.3V and with the adjusted ratio it measured that fine. I then lowered the supply to 12VDC (which would never swing that far in the normal use) and the telemetry voltage only drifted off by ~0.10 vdc and I'm using 2 decimal places with my telemetry display. I would not be concerned about resolution or accuracy. I would choose the appropriate series resistor for your required max voltage and measure full battery voltage.
If you didn't want any series resistor you could certainly plug it into a balance lead and scale the ratio to that. I'm thinking just do cell #1 if you do that and just watch the single cell voltage. Since you wouldn't know if all cells were balanced and wouldn't be reading full battery voltage anyway the single cell voltage would be all you'd need and would actually be easier to decipher looking at the screen. 4.2v is full and about 3.5-3.8v, or whatever you use for low, would be time to land. Even if you monitor the full pack voltage you won't really know if a single cell gets out of balance, you'll have to check that with a LiPo tester after you land.
Great job I have telemetryu in 6 receivers. I run one for 4 hours just to see if there would be a problem. None, I am right on for voltage using a multimeter as check. I have added a 4th wire to the sbus plug and I have hard wired to the positive lead of the esc. I had a little trouble when I tied to the red wire on the balance plug. Again thanks distance is great and now I have telemetry for my flight battery what else could we want. Thanks for sharing your discovery with us... I loved your video on the distance test we really got a bargain for $11 Thanks Chuck Gaydos
What a good find Shane. I will also use it on my glider. Only thing, your last comment about it destroying your radio could be true if you exceed the specified maximum input voltage of 8.4v. I would recommend not exceeding 2S battery packs. Thanks again for sharing.
Thanks for watching and or your comment. The 8.4 V limit is just the BEC voltage limit to power the receiver, the pack voltage sense input goes through a voltage divider so is perfectly safe for the receiver. After more research I've found that 18.81 volts is max wiring direct as shown here but if you add a 220K ohm resistor in series on the sense wire it will safely read up to 26.07 volts for a 6S pack. Just have to reset the ratio to scale the voltage to display properly.
Why you didn't crimp in the connector where the fourth thread was missing?
Initially I wasn't exactly sure which connector size it was to add another wire to the connector. I found a kit with a large number if connectors but it had 100's and was $20-30 and soldering it was free. Since I wasn't using SBus, on another RX after this video, I pulled the SBus connector pin out and moved it over. It was pretty easy so if you don't need SBus that is an easy way to get the voltage without soldering.
Really useful and interesting. Thanks.
When messing about for long periods of time either programming or testing etc on the TX16s, could it be plugged into the mains via the charging port, so it’s operational whilst charging or working of the mains so to speak, if that makes sense? Or simply a no no.
I sit and program often and I'll charge and use the radio at the same time. It will charge while powered on. I've heard people say not to but I don't know their logic behind it. My only reservation is I don't like moving the radio around while the USB cable is plugged in as I might wear out/break my USB port. I'm the same way with my cell phones, laptops, etc. though...
Yep great Tip, works fine Cheers 11.1v 3cell 2200 mah on a heli
This trick looks like a great find so I bought an R88 and bound with the FrSky D8 protocol. I can see A2 telemetry displaying voltage, and adjusted the ratio, but my issue is when I setup my widgets to display the reading on the TX16S main screen it shows 0v, like it’s disconnected. Under the telemetry screen it shows proper voltage data. Any idea what I’m doing wrong? I can get the RxBat and RSSI Telemetry to display but not A2 (pack voltage which is all I really want).
Are you sure you are selecting the correct telemetry value? Which Widget are you using? Let me know and I'll test it to see if I get it working. Did you see my Episode 1 using the Spektrum? I think I used the same Widgets for this one, might see something helpful in that video.
I assume you are on a TX16S? Which EdgeTX version and which Multi-Module firmware version?
@@shanesdiy thanks for the quick reply. Are you on RCgroups? TH-cam isn’t the best for showing my setup. I’m using a top bar widget location and running edgetx-tx16s v2.9.4 “providence”. I’m selecting Value as the widget type and choosing the Source as the “eyeball with signal” A2. It shows as such with 0.00 on the main screen but when I click Model and Telemetry A2 shows proper voltage.
The module firmware? I think it’s Module Status? V1.3.4.0 AETR. I’m not sure if that’s what I’m supposed to be looking at
@@shanesdiyI tried changing the name of A2, and used VBAT. For whatever reason this worked and solved the problem. I’m not sure why it wouldn’t work with the stock value of A2 but at least it works now on 4s reliably. Thanks.
Always at it!
Hello friend and thanks for this discovery. I had the r168. But now with the r88 it was no longer possible to display the voltage of the Lipo battery but with your modification it is possible why I never thought about what that x was before. question can I connect a 6 cell battery to the x connector, in your video you show that you give 15 volts and no more. thanks compliments of the channel.🤪
Someone else asked that below. 18.81 volts is max wiring direct but if you add a 220K ohm resistor inline on the sense wire it should safely read up to 26.07 volts for your 6S pack. This is because the receiver has a voltage divider circuit built in and the 220K resistor offsets the voltage the RX "sees". I haven't tested this limit myself, just learned by research and analyzing diagrams. Use at your own risk. You will, of course, need to properly calibrate the voltage as I've shown in this video to get it to read correctly.
Hi, thank you so much for replying to me. I'm Italian, I have the old r168 receivers which I really like, I set my RadioMaster tx16s with Open TX so that it talks to me when it reaches the 4s battery storage voltage, which is 14.2 volts and everything works great, Not Unfortunately I bought other receivers because I thought that the R88 v2 did not have the Vbat input as it did for the r168. But thanks to your video I noticed that the sbus connector has a fourth pin called X next to it and which can accept this voltage as input lipo, I know that there is a resistive divider inside, I had already thought about putting a resistor to attenuate the voltage value of a 6s, but I had no guarantee on this but since you also proposed it to me, for sure It works very well, obviously after some tests to be done. now I will make a purchase r88 v2 to modify it according to your instructions and if it works and if the radiomaster warns me with a voice message (model battery empty land immediately), I will be happy and I will buy others. at our airfield many have no longer bought Radiomaster receivers due to the lack of VBAT in telemetry, as soon as they find out about the change they will make hidden purchases of R88 v2. Thank you so much for giving us this gift of knowledge, you are a GENIUS. thank you thank you😀👍👌
@@hobbyfacile5342 I'm so happy you found the video useful. I also did a very extensive range test of the R88 V2 if you find that recent video. I have some more videos coming soon on another range test with some TX mods, as well as a video on the TX mods I'm doing. I may also do another video on the voltage with the added resistor to confirm it will handle the 6S voltages.
Hi friend, I am Dirk from Germany and have done the mod with the 220k resistor in series to my 6s LiPo with my R88 V2 and TX12 MK2 transmitter. It works fine and shows the right voltages that i have measured with my multimeter. From empty at around 20 V and full at around 25V my transmitter shows the exact voltages in 0.1V steps. You have to correct the values in the transmitter telemetry setup screnn like shown in the video, thats it.
And thanks to shanesdiy for this great information/channel about the A2 pin at the R88 V2. That´s the thing I have missed. For about 12€ at banggood you get a receiver with RSSI, RxBt and Fl(ight)Bt telemetry data without any external sensors 😀
I decided to risk a RX with this hack. Seems to work well with 3S and 4S packs from what I've tested so far. I was hoping to uses this on a 12S model, but it doesn't register correctly at those voltages. It didn't work with 6S either.
I'm far from being up to speed on basic electronics, but I'm guessing that the proper resister in the sensor wire would drop the voltage and get it back to where the output is variable, then just calibrate to the proper voltage. Any input on this would be appreciated.
18.81 volts is max wiring direct as shown here but if you add a 220K ohm resistor in series on the sense wire it will safely read up to 26.07 volts for a 6S pack. If you didn't add any series resistance when trying over 4S hopefully you didn't damage the receiver already.
DO AT YOUR OWN RISK...
I just did the math and if you add a 1.0 meg ohm (1,000,000) resistor in series with the voltage input this should allow it to accept up to 50.4 volts of a 12S (technically 51.8V max).
Just have to reset the ratio to scale the voltage to display properly.
@@shanesdiy Thanks for the help on the resistor. I was going to spend some time today trying to figure out what resistors might be needed. I had it hooked up to 12S power and I don't think it hurt anything. No magic smoke escaped. All RX functions seem to be normal. The voltage telemetry still works at 4S power. Yes, at my own risk!
Great video thanks however, I've just tried this with a V1 R88 and it doesn't seem to work. I only show 0.0v on the A2 output. I've double checked the wiring.
I repositioned the positive lead on the supplied plug to the A2 output (pin4). I plugged the positive wire into my balance lead (1,2 and 3 cell positive position). Tried to rediscover telemetry. Just shows 0.0v.
I'm guessing it only works on the v2?
Cheers.
Could be only V2, I don't have any V1's to test it on. Bummer but thanks for sharing your findings!
@shanesdiy I'll have a check next week of a v2 unit. I'll let you know how I get on. Thanks again for your content.
thanks for the great tutorial. Anyone knows the name/specifications of a 4 wire female connector that would fit?
I believe it is a ZH 1.5mm JST, 4 pin. I contemplated getting a kit off Amazon that has many different sizes but was hard to justify $25 for a kit when I just needed one for this project. Note, this was my best educated guess on the connector based on research and measurements so take that for what its worth... if I can find a smaller, cheaper kit or pack I'll pick it up and test.
@@shanesdiy Thanks a lot, I will get a some sets from aliexpress, different sizes, just a couple of euros/dollars, but takes some time to arrive
@@robdapraia3486 I just tried pulling the white wire pin 3 out of the included ZH connector to move it to pin 4 to use for voltage telemetry and with a small sharp pick it was actually pretty easy to get out. If you don't plan to use the SBUS cable turns out it is pretty easy to move the wire in the connector. If you happen to mess up one, you have 3 tries.
Nice! Yes, only need the “x”
Now how do you add an alarm to the voltage reading?
In part 1 voltage telemetry I show how to setup an alarm
th-cam.com/video/SDdAkyJB9Tc/w-d-xo.htmlsi=buXWUpiXKjn197gY
This is probably a basic question, but on my Radiomaster TX16S I can bind to the R 88 receiver, but I’m not getting any RSSI numbers back. I can bind to a different receiver like Frsky X8R and get RSSI immediately as well as battery voltage. Any ideas why I cannot get that on the R 88 receiver when I bind to it?
What protocol are you binding with?
That was it. I watched another vid on binding this specific receiver and it showed a different protocol then what I was using. Thanks again for your great vids and helpful info for all of us.
Do you know what the max input voltage is to A2? I'm wondering if I can get a read on a 6s 25V pack?
18.81 volts is max wiring direct but if you add a 220K ohm resistor inline on the sense wire it should safely read up to 26.07 volts for your 6S pack. This is because the receiver has a voltage divider circuit build in and the 220K resistor offsets the voltage the RX "sees". I haven't tested this limit myself, just learned by research and analyzing diagrams. Use at your own risk. You will, of course, need to properly calibrate the voltage as I've shown in this video to get it to read correctly.
perfect work ,, cool
Is it possible to get fc telemetry from the pin?
The 4th pin is the voltage sense input wire that we used in this video. The 3rd pin is the SBus output that can be connected to a flight controller to send 16 channels of data. I believe 15 channels is direct from the transmitter, channel 16 appears to be an RSSI value in my testing but I'm not 100% certain. Is this what you mean? If not I may need more detail of what you would like to do.
Se bastava spostare il pin dal sul connettore...cosi evitare di saldare ecc..
On my 2nd R88 I was able to easily move the pin in the supplied connector. Used a small pick or pin and be gentle. Another commenter was also able to successfully move the pin. No soldering required!
so you are using a scope . so you are calib the telemetry to PEAK to PEAK and not RMS as i assume more telemetry sensor use . ( also lets forget about relative / average ) but without explaining this to folks with cheap multimeter you are all calibrating to whatever...
No scope was used in this video, just the variable bench power supply which I previously validated with my Fluke 87V to make sure it was "close enough". Any average multimeter or even your LiPo checker will suffice.
Hello. I got a question. I use 6 pack LiPo with R88 and TX16 as TX. I did similar setup and I get voltage reading on A2. I calibrated it for current pack volyage (for example 25.2V) but after a flight it still shows 25.2 but when I measured pack voltage with multimeter it was 23.8V. It seems like R88 did not transmit correct voltage value in real time. On another video I heard that radiomaster RX support up to 4 pack batteries. Could this be a problem? What else I can check?
Did you install the 220K ohm resistor in series with the voltage sense wire? If not, you might damage the receiver. Without additional input resistance the maximum input voltage is 18.81V. The 220K resistor added allows it to accept up to 26.07V.
@@shanesdiy Great, thanks. I will do that. Maybe this was the reason it did not show correct voltage. I also tried 5 s pack with 20V and it still showed 25.2V, so 220K resistor could solve my problem.
@@shanesdiy How many Watt that resister should be? Could you write specific resistor characteristics?
I just use 1/4 watt, 10% or lower resistors. There is no current going through it so it's not important.
Just to clear up how the receiver monitors & scales the input sense voltage, there is an internal voltage divider. The built in resistor values for this divider are sized to only pass 3.3V (its max input limit) to the IC when 18.81V is applied to the sense wire. When you add 220K ohms to this voltage divider by placing it in series with the input wire, you change this scale to pass 3.3V to the IC when 26.07V is applied. When you sent 25.2 volts to sense wire without the added resistance, the receiver IC was potentially getting 4.42V but it can only safely take 3.3V max. There is also a current limiting resistor on the input to the IC so it may have helped save the IC input. If it will no longer read voltages properly you may have damaged it.
@@shanesdiy Well, I will give it a shot and hope it works. Thank you