I just bought an FrSky Taranis for my quad copter and needed to get the Mavlink data up on the Taranis LCD telemetry display. So here is my solution using a Teensy3.1 as a converter between MavLink and the S.Port on FrSky X8R.
See attached file below...
OK, I have checked some things. The telemetry value T1 contains the HDOP info. The Wiki describes correctly how to configure this here: https://github.com/Clooney82/MavLink_FrSkySPort/wiki/1.2.-FrSky-Tar...
I also checked my working configuration for the calculated 'Cmin' sensor, and this matches the Cmin details exactly as per the same wiki page.
Just for info, I am running OpenTx 2.1.8 and the latest copter217.lua script available from the Clooney82 repo on github. At the copter end, I am running Ardupilot 3.3.3 on Pixhawk FC. I have also tested this successfully on the 3.4-rc5 firmware, and also on latest Plane f/w.
Not flown any of my Pixhawk stuff in a while, but decided i need to get it all up to date and use it.
Having a few issues, got everything setup ... But for some reason i cannot get Cmin to display, and the HDOP value is exactly half of whats displayed in mission planner
The options described in the wiki for Cmin as lowest, i don;t have that setting so i chose MIN, but then all i get is the Min value Cels has been at.
Where am i going wrong?
Don, Are you using the Clooney82 version of the teensy code? Or some other version? I am involved in the Clooney82 code. You don't mention what you are using for LipPo cell monitoring. I presume though by your mention of editing the code and scaling the values etc, that you have built the single cell LiPo monitor resistor/voltage divider board, and have this connected to the teensy (or Pro mini possibly)? If that's the case, I'm sorry, I can't be much help as I haven't been involved in that area of the code and personally, I do not use this for LiPo cell monitoring. Instead I use the FrSky FLVSS sensors - I have 2 of them installed on my big hexacopter, monitoring 2 x 4s LiPos (wired in parallel). I updated the Wiki recently to describe how this should be configured, and you can find this info here: https://github.com/Clooney82/MavLink_FrSkySPort/wiki/1.-Setup#combi...
You should note, that the project does not support the use of the code on the Pro mini unfortunately. I know some other varients of the code do though, so possibly you are using one of those?
Doug, Sorry its taken me a while to look at this. I just checked it out and it seems the issue is caused by incorrect scaling on the part of OpenTx. If you look at the raw data coming into the ASpd sensor (on model telemetry page, with units set to -), you can see this correctly displaying the values in m/s, but by changing the units to m/s, it scales this incorrectly.
I'm guessing that if we were to connect a real-life FrSky smartport Airspeed sensor instead of the teensy (which just emulates those sensors using code) this would likely send the airspeed values through in knots (possibly?) so by choosing units of m/s it converts what it thinks is knots to m/s, thinking its being helpful. Of course, from Ardupilot, the Airspeed is sent in m/s natively (not knots), so we don't want the telemetry sensor config in OpenTx scaling this value at all - as our LUA script is expecting m/s. So in your switching the units to M as you did, OpenTx does not apply any scaling using this value for units, and the data correctly displays in the m/s scale (, and this value is then scaled in the LUA script to display KM/h on the LUA page) . The same would be true if you just set the units to '-'.
I have amended the Wiki to suggest that once discovered the user should edit the ASpd sensor and change units this way to correct this issue.
I have been following this for a while and while I have a working version on a pro mini, I want all the other options that a teensy has to offer.
I want to be able to monitor 2 x 3S lipos instaed of a 6S lipo. Am i right in assuming that i would just have to change a few things such as:
#define MAXCELLS 6
double _LIPOCELL_1TO8 =
0.0, // diverders 7-12 not defined because my network includes only 6 voltage dividers
then use the same r values for cells 1-3 on cells 4-6 for the voltage divider?
i already stupidly fried my first teensy (jack and electronics dont mix :) ) and dont really feel like replacing it again....
I found the problem. If I set the Taranis telemetry screen units to "m/s" as the Wiki shows its changing the ASpd value by some factor that is lowering the value of ASpd. If I set units to meters "m" the value of ASpd is passed to the Lua script correctly. If you confirm that the Wiki should probably be changed. Aslo, I have the plane Lua modded to display Imperial Units. But, that means if your setting any alarms in the Taranis they have to be set in metric. For my own needs I'm going to change the Tennsy code to make the change in the values before the values are sent to the Taranis so I can set the alarms in Imperial units. I've looked at the code and it is a fairly easy change.
Paul Atherton said: