Build your own telemetry sensors.

[Chris Bott - Moderator]

You have the Cells voltage showing the total of all cells.

To see individual ones you need to add calculated sensors.

So

Add a new sensor

Type: Calculated

Formula: Cell

 

Then chose which cell or just lowest, highest or delta.

 

Note: Cells will only show up when a battery balance connector is connected.

Edited By Chris Bott - Moderator on 26/05/2019 11:31:09

[Andy Halmshaw]

I may be able to help here.

If you go to the Telemetry screen on your Taranis transmitter and copy "Cels" (in this case) three times, then edit the first line as per the second photo. Then edit the second line as per the third photo, you will have the individual cell votages, and obviously the third line the same but inserting 3 . This will work for any number of cells in a pack (only four with Chris's telemetry module), just keep copying for the number of cells line.

You next need to edit the display page on your Taranis. Then when you long press page on your Taranis transmitter you can display your telemetry data as per the fourth photo, as you can see this is an old pack where the cells are slightly out of balance even though I use a balance charge every time.

Hope this is of help.

Andy

Photo 1

Photo 2

Photo 3

[Andy Halmshaw]

Hi David

I think that the flashing stars as you call them is when the telemetry data going to the Taranis changes. If the data is very stable no flash, when the value changes they flash.

Andy

[Chris Bott - Moderator]

Posted by David Tayler on 26/05/2019 09:36:50:

Thanks for the project I am gradually getting my head round it. One last question is there a cheap airspeed sensor available?

David

I'm not sure about cheap but I think this is the sort of thing you're looking for.

[David Tayler]

Thank you all for the help ,especially Andy in this instance. I can now see all the cells and the total. My current sensor arrived yesterday so I will add it. I think for the air speed sensor it may be as cheap to buy the Frsky modulle,even if that seems like cheating!

[Chris Bott - Moderator]

Quick update. We're now up to 78 PCBs that have been requested. That number has astonished me, so many thanks for all the interest.

Hopefully the reduction in questions here means that those that have built some sensors are doing OK?

I think that demand for the boards is possibly over but a new batch has turned up today. These incorporate all the changes that have been suggested (along with a correction to the resistor numbering on the last batch - compare the pic below with the previous one - doh!)

These have come to me in 4s just to save me taping them together for postage. They snap apart easily so I can still send any required number.

I'll build one up over the next day or two just to make sure everything is OK.

Chris

[Chris Bott - Moderator]

Latest version board now built and fully tested. All good.

So boards 77&78 are in the post. All requests fulfilled.

[Kevin Fairgrieve]

I am still waiting on a few components coming from China!!

On holiday to Malta next week, if upon my return they are not here....Paypal dispute..

Kev

[Paul Lewis 3]

Here is my latest sensor with a MPXV7002 airspeed sensor using A0 and A1 with a voltage divider on the ADS1115. The ADS1115 connects to the same pins (A4, A5, VCC and GND) as the GY-63. I also have a Hobbywing RPM sensor which measures the pulses from any two of the output wires from the brushless ESC. The RPM sensor connects to PIN8 on the Arduino and takes it’s VCC and GND from the second SPORT connector. I am also using PPM via the SPORT protocol to reset the Airspeed and to change between different vertical speeds calculations using compensation from the Air Speed sensor controlled via LUA scripts.

Next I think I will try and create a 6S version with additional 100nf capacitors to ground try and stabilise the cell voltages. I will also use the ADS1115 to do the Current Sensing using an external HGLRC XT60 connector. But I need to get to grips more with Eagle PCB design software first.

Chris did you use Eagle to design your PCBs?

[Chris Bott - Moderator]

Wow Paul you've really picked the ball up and run with it there.

Nice job. H

have you gone about calibrating RPM? I.e what sort of numbers have you put where? (OpenXSensor and the Tx).

How do you fancy picking up temperature sensing? That's something I'd be keen to follow.

I'll PM about PCB design as that's a whole new subject.

Cheers

Chris.

[Paul Lewis 3]

Hi Chris, I haven’t calibrated the RPM sensor yet I have just connected it to a test rig and checked the numbers go up and down as the motor speeds up, I will be mounting the senor to a model very soon and then using my handheld optical RPM sensor to find the correct scaling factor as it depends on the number of poles in the motor.

In the config_basic I just have “#define CALCULATE_RPM YES” As you need this for it to send the telemetry from what I understand the rest is setup by using a calculated sensor in OpenTX but I will let you know.

I thought a about temperature but it seems to only support the analogue pins on the Arduino and not on the ADS1115 so I have no pins free however I guess that if I don’t have a Baro or ADS1115 I could use pins 4 and 5 or have two oXs sensors.

[Michael Hadaway]

Hello Chris.

I have been following this series with interest since the article in the magazine.

Its still a bit of a mystery to me, but I would like to purchase a few of your project boards and have a go.

I understand that you can supply them for £2 + £1 p&p and paypal is accepted.

I would wish to bye three please.

Mike Hadaway

[Chris Bott - Moderator]

Hi Mike

I'm away on holiday at the moment but yes that's all correct.

If you send me a PM, I'll get back to you with PayPal details etc and you can let me have your address. No rush though, I can't do anything until the start of next week, sorry.

[Chris Bott - Moderator]

If anyone is expecting a reply about purchase of PCBs could you look at your PMs please.

The last two enquiries had replies sent by me about a week ago, neither has been read yet.

Cheers

Chris

[Stephen Jones]

Hi ,

I have a Adafruit Pro Trinket.

Is it any use for something like this.

Steve

[Michael Hadaway]

Hi Chris

When compiling the sketch I get an error regarding <Arduino.h>. The error report is.

Arduino: 1.8.9 (Windows Store 1.8.21.0) (Windows 10), Board: "Arduino Pro or Pro Mini, ATmega328P (3.3V, 8 MHz)"

In file included from C:\Users\oxfor\AppData\Local\Temp\arduino_modified_sketch_368203\sketch_may30a.ino:369:0:

C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.21.0_x86__mdqgnx93n4wtt\hardware\arduino\avr\cores\arduino/Arduino.h:153:16: error: conflicting declaration of 'void setup()' with 'C' linkage

void setup(void);

^

C:\Users\oxfor\AppData\Local\Temp\arduino_modified_sketch_368203\sketch_may30a.ino:1:6: note: previous declaration with 'C++' linkage

void setup() {

^

In file included from C:\Users\oxfor\AppData\Local\Temp\arduino_modified_sketch_368203\sketch_may30a.ino:369:0:

C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.21.0_x86__mdqgnx93n4wtt\hardware\arduino\avr\cores\arduino/Arduino.h:154:15: error: conflicting declaration of 'void loop()' with 'C' linkage

void loop(void);

^

C:\Users\oxfor\AppData\Local\Temp\arduino_modified_sketch_368203\sketch_may30a.ino:133:6: note: previous declaration with 'C++' linkage

void loop() {

^

exit status 1
Error compiling for board Arduino Pro or Pro Mini.

[Chris Bott - Moderator]

Hi Michael

Wow there's a question.
As reported, I'm no expert at all, this has been my own voyage of discovery.

Hopefully someone with some real knowledge might come along.

In the meantime my guess would be that the sketch has somehow become corrupted.
What happens if you try to compile the original sketch as downloaded, before you try any changes?

Chris

[Mike Blandford]

Where did you get the Arduino IDE from?

Mike

[Michael Hadaway]

Hello

Mike Blandfird may have a good point. I have downloaded the IDE ( Arduino 1.8.9 ) from Windows store 1.2.21.0.

Is this OK?

I note, Chris, that you say to compile the original sketch. I have been unable to find the sketch to download.

From your post 14/4/19 were the link "here" is given, I left click on openxsensor and find a lot of files.

I downloaded oXs_config_basic_h and oXs_ config_advanced_h as advised in the magazine article.

Then pasted into a new sketch file. Even before changes unable to compile.

Hopefully it will be clear to you were I am going wrong. Incidentally the sketch for the servo tester compiles OK

and the unit works as expected.

Mike Hadaway

[Chris Bott - Moderator]

Hi Mike

I think we can fix this fairly easily. Im at work just now so can't spend much time.

I downloaded the IDE from Arduino website here it's currently showing version 1.8.9. If you have used the servo tester sucessfully then your IDE is probably OK.

The openxsensor sketch comprises many files. it sounds like you don't have them all.

We'll have to work out the best way to point you to them. Or I might be able to email the whole thing in a zip file later.

Chris

[Chris Bott - Moderator]

The full .zip file is here

Once downloaded it needs unzipping but leaving in the file structure just as it comes.

As you'll see, there are a LOT of files in there.

Cheers
Chris

[Michael Hadaway]

Thanks Chris. Will give it a go.

Mike

[Michael Hadaway]

Thank you so much Chris. The zip file downloaded perfectly and compiles without errors.

I do get a warning that the global variables use 92% of dynamic memory and stability problems may occur.

However I presume that once I have edited the sketch for the sensors I am using, ie just current and voltage at first,

that the memory issue will be resolved.

Thanks again for you help and I hope that my experience may help others who may be having problems.

Cheers

Mike

[Michael Hadaway]

I was compiling for a 168 board in error for a 328.

Now all OK.

Have tested my first sensor and can report getting good cell voltages.

encouraged to proceed.

[Chris Bott - Moderator]

Just a little bit of feedback. Between everyone that's contacted me, I've now sent out 102 PCBs. I've had a daft lingering hope that we'd crack the 100 barrier and now we have.

So - many many thanks for all the support and interest, it makes it feel very worthwhile.

Are there any more success stories?
Or have most people had a go and given up?

Chris