Use MultiWii GPS telemetry for FrSky telemetry

[seikurou]

Have a HK MultiWii pro with mtk gps. Have an fld display on my tgy9x. Fld connected to telemetry module. Any way to hook up telemetry port in mw board to frsky d8r-ii Rx for GPS coordinates?

[QuadBow]

The related dicussion can be found under http://www.multiwii.com/forum/viewtopic.php?f=7&t=1929
GPS support is included, as well.

[seikurou]

Pretty confusing thread...
So what would I need to buy to get it to work?
Some thing like this: http://www.ebay.com/itm/Mini-RS232-MAX3 ... 5b05e33590
is that it?
Is that code compatible with mw 2.3?

[QuadBow]

Pretty confusing thread...

Due to another request I provided a non-standard multiwii package at http://www.multiwii.com/forum/viewtopic.php?f=7&t=1929&start=300#p61873

So what would I need to buy to get it to work?

Since you got already the FLD-02 and a telemetry transmitter/receiver combo (like http://www.frsky-rc.com/product/category.php?cate_id=14 and http://www.frsky-rc.com/product/category.php?cate_id=16) you only need a level inverter.

Some thing like this: http://www.ebay.com/itm/Mini-RS232-MAX3 ... 5b05e33590
is that it?

No, you don't need a level conveter 12V/5V, but a 5V/0V level inverter. That can be realised with one single transistor as described in the mentioned thread.

Is that code compatible with mw 2.3?

The code I have uploaded as mentioned earlier has been transferred to multiwii 2.3.

[seikurou]

Thank you so much!
Would this work on the HK 328p and HK MultiWii pro? Where would I plug stuff in?
Can you link a power inverter that would work?

Your reply is most appreciated.

[seikurou]

Would I be able to use a Bluetooth module at the same time for both of these boards?
Currently know nothing of the more complex aspects of MultiWii.
When you say transistor I'm sure which to get. Even then, I don't know what to do with it to get it to work.
How do I know what serial is what?

[seikurou]

Ended up getting a TTL TS232.
Will your code work with that?
Still am unsure about the connections that have to be made onto the board. (HobbyKing MultiWii 328p, Witespy MW Pro Ez3.0)

[QuadBow]

Can you link a power inverter that would work?

You need something like this: http://www.multiwii.com/forum/viewtopic.php?f=7&t=1929&hilit=direct+frsky&start=50#p26160

Would this work on the HK 328p and HK MultiWii pro? Where would I plug stuff in?

You need a free serial port to connect your FRSKY telemetry-compatible receiver's serial port to. Therefore, a p328 based flight controller is not well suited for telemetry since it has only one serial port, which is used for the connection to the PC.

Would I be able to use a Bluetooth module at the same time for both of these boards?

For the Mega2560-based HK MW PRO (the one with enough serial ports) you can use bluetooth at serial0 for a connection to your smartphone and telemetry at serial3 for a connection to your modded transmitter or FRSKY display in parallel.

How do I know what serial is what?

In the file config.h I provided the serial port 3 is selected via the definition

Code: Select all

#define TELEMETRY_SERIAL 3

Ended up getting a TTL TS232.

I am not sure whether that will work. Actually you can solder it as mentioned in the first bullet or you buy it. One example that has been reported to work can be found here http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16672

[seikurou]

For serial 3, I know it's serial 3, but where physically on the board is serial 3?
I would connect the receiver to the mini-b plug through the thing you linked me?
Are the ports the I2C ones?
Not very good at reading schematics... so could the FrSky/TS232 might serve as a substitute?
Thanks

[QuadBow]

but where physically on the board is serial 3?

Your dealer should be able to answer this question. I still don't know exactly, what board you are talking about.

I would connect the receiver to the mini-b plug through the thing you linked me?
Are the ports the I2C ones?

No, connect the Tx pin of serial 3 of your fligth controller via the converter I mentioned to the Rx pin of your receiver http://www.frsky-rc.com/product/images/pic/1361843356.jpg in the way that is described here http://www.multiwii.com/forum/viewtopic.php?f=7&t=1929&hilit=direct+frsky&start=50#p26160

Have fun!

[gandalf33]

Hello Quadbow,

I have setup my multiwii 2.4 quad, using a D4R-II and a Taranis. I have installed a serial connection through a ful-1, and all that works fine. The telemetry link between the taranis and the FC is working, but I have an issue that not all values seem to be properly transfered. I'll try to establish a full list but for example vbat, or number of sats seen by the GPS, lagitude and longitude, accl, all that is well received on the taranis, but heading for exemple, does not get properly seen by the taranis (either 0 or 65xxx), nor does dist or alt.

Do you have any hints on how I should approach this ?

G

[QuadBow]

Hi gandalf33,

heading is depending on the compass, alt on the baro. So, does your board support those features?

Which code version do you use? The latest from the trunk?
https://code.google.com/p/multiwii/source/browse/#svn%2Ftrunk%2FMultiWii_shared
There you can select e.g. whether to take the altitude from baro or from the gps device via definitions in the Telemetry section of the file config.h.

Do you use an i2c gps device? In this case altitude, course and distance are disabled at the end of the file gps.cpp.

[gandalf33]

Hello Quadbow,

Thanks a lot for your answer. I should have mentionned that all of what I'm missing on the Taranis IS in fact available on Ez-gui (or wingui or the multiwii config tool), but obviously bluetooth range makes it inpractical for in flight use.

My FC : http://www.drotek.fr/shop/fr/home/365-d ... c5883.html (baro is included, no MAG)
My GPS : http://www.drotek.fr/shop/fr/home/512-m ... &results=3 (serial GPS, i2c MAG)

Yes, I use the latest trunk (r1774). I will do a listy this morning of what data does get into the Taranis, and what does not, surely something to learn from this !

In config, i have enabled baro alt and mag course

Thanks again for your help

G

[gandalf33]

Ok, progressing on the heading front (will investgate other potentially missing data)

1) heading is NOT displayed on the taranis until GPS lock is achieved. Loocking at the cleanflight frsky.c (https://github.com/cleanflight/cleanfli ... ry/frsky.c), the autor is mentionning this : "// Heading is only displayed on OpenTX if non-zero lat/long is also sent", and is therefore sending dummy data when GPS lock is not available.

2) Knowing that, I have taken the quad outside where I have gps lock, and yes, heading does get transmited this time, but there is still an issue. Ez gui gives me heading in -180 to +180 format. When I am in the 0 to +180° direction, heading gets properly transmited, when on the -180° to 0 however, you get 65535 - heading value (-100° will display 65435) which i initialy took as bogus data

G

[LutzB]

Ez gui gives me heading in -180 to +180 format. When I am in the 0 to +180° direction, heading gets properly transmited, when on the -180° to 0 however, you get 65535 - heading value (-100° will display 65435) which i initialy took as bogus data

This is because the Taranis expects an unsigned value. I had the same issue while experimenting with the SPort data. MultiWii calculates the heading in the range -180 up to +180 degrees, but the FrSky telemetry defines this as 0 up to 360 degrees. So some calculation is needed to transform to the right range.

Code: Select all

FrSkyHeading = ( heading + 360 ) % 360