The attached PDF is a description of how FrSky's S-Port bus operates to connect external sensors like altitude and current to a receiver. It details the format and describes traffic on the bus including a log of actual transactions.

If you are interested in looking into it further on your own equipment, the log was captured using an Arduino sketch on a Teensy 3.5 board which can be bought for about $25. Information on hooking it up, the code for the logger, and some other similar uses for the logger are available here: https://www.rcgroups.com/forums/show...us-Data-Logger

For anyone who may be interested I've posted a how-to for building an Teensy 3.5 based s-bus SD card logger I'm calling the Receiver Snoop here: https://www.rcgroups.com/forums/show...r#post45890539

The capabilities are similar but somewhat different than the LQBB approach.

I recently decided to try switching from FrOS to OpenTX. Here is a description of that experience along with first impressions and a quick overview of OTX for those who may be considering such a switch.

Rick

Some recent inquiries prompted me to consider that there is more to setting up telemetry than just a simple explanation. I certainly had my share of confusion and needed some help when I first started with FrOS. A search didn't find much available documentation so perhaps it's time a more comprehensive reference was written. So Here's a shot at it.

This paper covers hooking things up, logging data, displaying values, voice announcements, creating custom voice alerts, timers, using telemetry as a control input, and the use of special functions and logic switches to implement these.

The accompanying log file is nothing special, just a sample for those who would like to look at one. Since RC Groups does not support .CSV it's posted as a .TXT. Download it and delete the .TXT from the filename so it will open in a spreadsheet as a csv file.

For those who would like to build a sailplane setup using the FrSky Operating System on their Horus transmitter but need help getting started or want guidance applying some of the available features, this guide is for you. The approach taken is building a setup from scratch rather than a feature-by-feature description.

The guide was written with an X10s using 1.3.04 firmware and the model files attached are for that system. The Guide and sound files should apply to the X12 as well but the model.bin files will not AFIK. These files are not necessary for following the Guide.

I can consider myself a glider guider by only the loosest definition so I hope my assessment of desired behavior is close enough to be useful and that this guide will save some people time and frustration figuring things out.

Rick

EDIT: This is a new version of the files. In the original, the Demo NFM model file accidentally had a screenshot special function enabled. This can be a real help if you need images for a document but a real nuisance if you don't so it was removed. The files are otherwise the same.

F26

Attached is a Tutorial on ex-mixers in FrSky's operating system for the Horus transmitter line. It includes an overview of the structure of an ex-mixer and uses examples to illustrate how the various features work. It also touches on the use of flight modes and curves.

For me the ex-mixer section in FrOS was the least intuitive and most confusing section. I decided that writing a tutorial for others was the best way for me to learn it and indeed writing the Tutorial has forced me to work my way through it. Hopefully this tutorial will save others at least some of the work.

Rick

EDIT: Attached is an updated version of the tutorial. This version adds Example #7 applying speed values to flaperon movement and a Function Flow diagram, as well as some minor wording clarification.

V2-1 corrects an error in example #4.

239

The attached sheets are not really full product reviews. They are written for fliers familiar with the Eagle Tree Guardian. The basic assumption is how the subject device compares to a Guardian for the line-of-sight fixed wing sport flying for which the Guardian was designed. Only features relevant to that application are included. The Vector, for example has many FPV and multirotor features that have no counterpart in a Guardian or this type of flying so these are not covered.

It's easy to get excellent self leveling with a Guardian without the detailed understanding described in this post. This is for people who are having problems, seeing things they don’t understand, having trouble achieving a specific result, or are just terminally curious. If none of these apply, please feel free to stop here and just follow the procedures in the New User’s Guide.

There is a lot of confusion among new users and even experienced users about how 2D manages flight. We know it does self-leveling when the sticks are centered but the behavior when sticks are moved is often misunderstood. To simplify, only bank angle will be considered in the rest of this discussion, pitch works the same way but bank angle is what people usually ask about. 2D doesn’t really manage yaw at all. If heading-hold is active it uses the ailerons to bank the plane onto the target heading. With no heading-hold it just levels. The rudder is inactive except for auto-turn-coordination if selected and the always present rate reaction to turbulence.

Concept:
Responding to a query, experienced users typically describe 2D something like this; “The stick controls the bank angle as a percentage of the max angle set in the software. Full stick means 100% of the 60° max angle (default value).” In practice, however, there is more to it. The Guardian manages the bank angle to a “target” value based on three factors as follows.

1) Software “...Continue Reading

The attached PDF contains an illustrated description of some common encoding methods used in the hobby. It probably has more detail than most people need but you may find it interesting if you enjoy knowing how things work.

Some technical background is required to follow the descriptions. If you know that a millisecond (ms) is 1000 microseconds (µs), that analog refers to continuously variable data like a speedometer with a needle while digital refers to discreet values like a speedometer with digits, and that digital data is represented in binary, then you probably know enough to get something out of this.

Rick

4-19-20 431

Attached is an updated version of the Guardian New User's Guide. This version has been updated to include the features added with the Eagle Tree software release 10.63 and firmware 1.24 and later. Also included are a few new tips that have surfaced since V1 was published over a year ago. (How time flies!)

For new users with software 10.52 and earlier, please consider upgrading. 10.52 has been discontinued. The current firmware is 10.65 which is the same as 10.63. If you choose not to upgrade, follow the original New User's Guide below. The main features added in 10.63 are bulleted here with more detail in this link: https://www.rcgroups.com/forums/show...2&postcount=12

• Modes may be assigned to each position of the mode switch, with or without heading hold.
• A provision was added for setting the level in flight and buttons for tweaking the level in the user interface.
• A button was added to re-zero the gyros.
• The 3D "center stick" zone was adjusted to make fine control movements smoother.

I hope this document will ease the transition into Guardian flying for many new users, and maybe encourage some existing users to move to the newer software/firmware. It really is worth making the change.

Special thanks to the following contributors and all those who offered their thoughts and suggestions in the RC-Groups Guardian thread and, of course, Eagle Tree for making such a fine product.

• Prof100
• Snowflake6515
• JayY
• BobbiesBrother

Rick

An explanation of how power flows through a Guardian equipped system to the servos and some strategies for managing installations with higher power servos.

The attached pdf is a Guide for new users of the Eagle Tree Guardian 2D/3D.

The manual is loaded with information but it seems to be hard for first time users to put the needed pieces together to complete their installation. This guide is written primarily as a how-to. It is organized in a way that should make it easy to follow at different stages and includes some things that have been learned along the way in this forum, including some suggestions for various options and FAQs as an appendix.

I'm hoping it will be useful to newcomers.