AutoQuad native Graupner HoTT telemetry (update jan 2015)

Radio, Telemetry, FTDI/USB, ESCs, Motors, etc.

AutoQuad native Graupner HoTT telemetry (update jan 2015)

Postby joebar.rc » Sat Mar 15, 2014 10:31 am

Jan 2015 update: support for M4v2

Update jan 2015: scroll down to bottom post

With the upcoming DIMU boards arriving soon in the shops:
I'd like to introduce full Graupner HoTT telemetry running directly on the AQ6 board using the UART2.

The Uart2 is available using the DIMU, the DIY CAN board or when you feel adventurous, you can solder it direct on pad 3 J2.
Only the TX wire is needed, the protocol is half duplex and will switch between send and receive using only the TX wire.
(the used uart is obviously free configurable, but on aq6 the free available uart is uart2)

HoTT UART2.png
Possible AQ6 HoTT connections

Notes: this FW is based on the Graupner protocol update from oct 2013 and newer. ALL available Graupner modules are emulated: Generic Air module, Electric Air module, Vario module, GPS module AND ESC AIR module.
Thats right, when your lucky to have ESC32's using CAN, the available telemetry will be displayed in the ESC AIR screen.
If you also using Quatos, the total thrust in grams and thrust per motor in Kg is also displayed.

ESC32 telemetry per motor

Most features are demonstrated in the video including;
Battery Voltage, current, capacity used, onboard temperature, GPS postion, altitude, vario, speed, direction, bearing to home, distance to home, recorded waypoint number, number of mission waypoints, current waypoint, distance to next waypoint, waypoint altitude offset, flight mode display, motor RPM, motor current usage, motor voltage

Note: the Graupner HoTT transmitter will only look for modules for approx 10 secs, the AQ should be booted within that timeframe.
If you cant see all modules, the timeout has probably kicked in and it is sufficient to power cycle the transmitter.
The ESC AIR module will only be displayed if you have defined CAN esc's AND they can be found active during the HoTT init.

A standard HoTT transmitter will also record all data, so with this function you now have very long range telemetry (up to 4Km distance with GR24) and logging.
Not as detailed as AQ's own logging obviously, but for flight recording it is very useful.

Extra functions
Besides the Graupner HoTT telemetry function, more functions are added in this FW:
- Support for a currentsensor using the pressure2 pads
- Waypoint recording

For the current sensor 2 params are added:
Code: Select all
SPVR_CUR_OFFSET            0.0f            /* Currentsensor offset voltage @0A */
SPVR_CUR_RES               (20.0f/1000.0f) /* Currentsensor resolution in mV/A */

if the SPVR_CUR_OFFSET is 0, the currentsensor measure is disabled. It should be measured direct on the pads when no current is used.
note: for ACS75x it is usualy 0.5*Vref, in this case close to 1.6-1.7V based on 3.3V Vref voltage

For waypoint recording 1 param is added:
Code: Select all
NAV_WPREC_CHAN      0           // radio channel for waypoint recording; set to zero to disable
Look in the channel assignment table in the QGCs gui to see which number to use for your preferred channel.

I've been using it since Jan 2014 and thanks to James (jdmagoo) testing fully southern hemisphere compatible :)
It is considered experimental, i've had countless hours flight testing and the last month 3 others have been testing it too but that is far to low to call it stable.
Attached two complied versions based on r360, one for AQ6 r1 - AIMU r1 and one for AQ6 r1 - DIMU v1.1
Also attached the set of fw files that have been added or updated to support this fw.
Because of the experimental stage, I try to keep up with the svn releases and post/upload compiled versions

I hope you will find it useful and fun, I already depend on it and having full range telemetry without any additional HW is very nice.

Oh, one more thing :)
If you add a bluetooth module (cheap GLB or FlyDuino's/Viacopter version) to your HoTT MX/MC/MZ transmitter, you can download an Graupner HoTT app for the android devices.
With that you can connect to your transmitter and have very nice HoTT telemetry screens on you phone/tablet.
A bonus is to have live GPS maps. Again this is without having an AQ GCS and only using the HoTT protocol..

Update april 2014:
I added the HoTT text mode function. With that a 8*21char text field is send which can basically contain just about everything.
What I done for now:
Overview screen with full mission info
ESC32 telemetry (if found)
First attempt for autoquad settings, yes thats right, edit the autoquad params on the radio.
In this version a selected set of params can be edit, I'm open for suggestions..

Update may 2014:
~ Updated to AQ7-r397
~ Much! faster transmitter key response in text mode. Found a way to first read the key and then create the text screen. Saves 1.5s every key press!
+ HoTT textmode Waypoint editor. All waypoint either recorded or uploaded can now be edited on the transmitter, change the type etc.
Last screen can also be used for overal waypoint managment ie: change all altitude (increase/decrease by x meter) or change all speeds by x m/s
+ First proof of concept try for GeoFence. With this option you can set a circular fence around the home position which when breached, the user control (pitch/roll) will be limited to 20%. So you still can fly but very very slow.
When re-entering inside the fence the full user control is restored. Warnings on 10% fence limit and fence breach.
+ On request the throttle factor setting is added to the settings screen. If needed you can quickly adjust it on field eg: using different #cells
+ Compatible with the upcoming AutoQuad M4

Update june 2014:
AutoQuad experimental r403 + HoTT jun 2014
In this release:
~ Updated to AQ7-r403
+ introduced a param: TELEMETRY_HOTT. Set on 1 (default) is HoTT telemtry enabled, set on 0 HoTT telemetry is disabled.
Reason is the request to use the extras in this firmware without HoTT equipment.
+ Point of Interrest altitude in Waypoint editor. With this param you can set the camera gimbal POI. As example the copter can fly @ 10m altitude and keep the camera pointed to the POI object @5m. The tilt angle will now be
automatically controlled and pointed at the object.

+ Big extra: follow me and fly to position mode enabled. When in position hold and enabled in the android app, AutoQuad can 'follow' the android device. Be careful to test! Android AQGCS v0.3.x and higher required.

Waypoint editor

Geofence demo

Update july 2014:
~ Updated to AQ7-r416
~ Big redesign on the HoTT menu screen.
-Central main screen,
-Split settings in Attitude (PID/Quatos), Position & Altitude, Misc settings.
-Added a general info & tool screen. Info about the HW, FW, uSD status (filename, space)
-Added reboot button
-Waypoint editor in two screens;
- Waypoint editor per waypoint
- General waypoint changes (All altitudes, all horizontal speed) AND import/export waypoints to uSD card!
~ HoTT text screens can also be maneuvered (main menu, next) using a free channel if available. Set the channel in
RADIO_HOTT_CH and use long (>0.5s) click for main menu and short click (<0.5s) for next. Best to use a temporary switch like SW1 on a MX20/16
+ Waypoint Skip switch: Waypoint Record switch will record in any mode other than MISSION_MODE. In Mission mode the switch will allow skipping a WP ahead (next WP).
+ Waypoint export/import function to uSD card
+ New Waypoint command: JUMP TO. With this command you can repeat a mission sequence for a number of times
Example: WP#1 GOTO, WP#2 GOTO, WP#3 Orbit, WP#4 JUMP TO #1 for 3 times, so it will execute the same mission 3 times and than end the mission.

Note: the TELEMETRY_HOTT needs to be adjusted, it was 0 to disable HoTT, 1 for enable. It now contains the HoTT delay for the protocol for
finetuning. For normal up to date HoTT fw and normal (not lite) receivers set to 800, for older fw or lite receivers you need to find the best working
yourself. My lite receiver seems to like 650.

As of r406 the radio numbering has changed, the radio_type is now depreciated and radio_setup will be used. It is already configured for HoTT sumd on radio port 0
Yes, from r406 on you can have 3 receivers connected if enough uarts are available. (AutoQuad M4 will be the 1st that it can be used on)

Update sep 2014:
~ Updated to AQ7-r429
+ non-ESC32 throttle endpoint calibration function. A param is added: MOT_ESC_CALI. After connecting to the QGCS, set the param to 1, press transfer and write.
now remove the lipo, REMOVE THE PROPS and reinsert the lipo, the FW should detect the request for calibrating the end points. After the calibration
the param is now set to 0.
~ changed the arrows in the text menu's to > and <, the character set on MZ series radios dont have the arrow characters like on MX series radios

Update jan 2015:
In this release
~Updated to AQ7-r445
+ added support for M4v2
+ option to use M4v2 comport 1 or comport 3 (both on expansion connectors) via param TELEMETRY_HPORT
TELEMETRY_HPORT = 0 ; comport 1, TELEMETRY_HPORT = 1; comport 3
For using comport1 set the mavlink communications to none on that port. (suggestion to prevent mavlink conflicts)
-> QGCS, Misc settings, Communication Ports, Serial Port 1: protocol NONE and save
+ Support for ESC32v3, support for AQ PDB, current sensor and voltage via CAN
+ Support for using Quatos with other multirotor ESC's like Kiss/SimonK (experimental, limited user experience).
Default behavior is other ESC, for using onboard esc set MOT_ESC_TYPE to 1, for using PWM connected ESC32, set MOT_ESC_TYPE to 2.

Please not that due to more configs testing has been limited, testing has been done on m4v2 using comport 1 and 3 and AQ6r1 with Dimu

PID version for M4v2 ...

Quatos version for M4V2 - Please make sure your Quatos license number is in the license field. ...

A full wiki page is made ... telemetry/

and the download section now contains a version build for AQ6 rev1 & DIMU 1.1 boards and AQ6 AIMU rev1 boards. Source code also in download section.
HoTT_wp_1.PNG (391.38 KiB) Viewed 28149 times

HoTT_esc32_1.PNG (405.76 KiB) Viewed 28149 times

HoTT_settings_5.PNG (436.3 KiB) Viewed 28149 times
Last edited by joebar.rc on Thu Jan 08, 2015 11:25 am, edited 8 times in total.
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Re: AutoQuad native Graupner HoTT telemetry

Postby chschmid » Sat Mar 15, 2014 4:32 pm

Wow Menno, what a tremendous job. Makes me think of changing to GRP.

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Re: AutoQuad native Graupner HoTT telemetry

Postby plexus » Sat Mar 15, 2014 5:10 pm

Again very good job. :o
Thanks Menno.
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Re: AutoQuad native Graupner HoTT telemetry

Postby LPR » Sat Mar 15, 2014 7:22 pm


Very nice work.

Graupner is not very popular in the USA. Do you know of other RC Transmitters could use your set up?

Taranis is what I have and it would be great not to have to use all the individual sensors with the AQ.

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Re: AutoQuad native Graupner HoTT telemetry

Postby joebar.rc » Sat Mar 15, 2014 7:35 pm

I believe the frsky taranis uses more or less the same half duplex technique for the protocol, so part of the code could be modified or used for the protocol.
The actual data conversion is obviously different. Peter has a taranis and already modified my mav2hott code to display some data, so I guess it should be possible to port it to AQ.
It is however time consuming :)
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Re: AutoQuad native Graupner HoTT telemetry

Postby kinderkram » Sat Mar 15, 2014 7:50 pm

Excellent stuff, Menno.
The Graupner boyz will love it! :D

Waiting for confirmation or can we transfer it to the Wiki?
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Re: AutoQuad native Graupner HoTT telemetry

Postby LPR » Sat Mar 15, 2014 9:10 pm

joebar.rc wrote:I believe the frsky taranis uses more or less the same half duplex technique for the protocol, so part of the code could be modified or used for the protocol.
The actual data conversion is obviously different. Peter has a taranis and already modified my mav2hott code to display some data, so I guess it should be possible to port it to AQ.
It is however time consuming :)


I looked over the forum posts and it looks that there is at least six people using the Taranis with AQ.
If there is more interest it might be worth considering.

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Re: AutoQuad native Graupner HoTT telemetry

Postby Jdmagoo » Sat Mar 15, 2014 11:30 pm

This is great work Menno!

One thing I will say is the GPS accuracy reported in cm is absolutely fantastic and makes PID tuning a lot easier. I never takeoff now until I get an error below 90cm or better. Such a great feature.

The distance to next waypoint is cool and really makes you appreciate the telemetry. I can't wait for the DIMU to be released so we can try the other great features that CAN brings.

I've purchased the breakout board that Menno designed for the external current sensor from oshpark, just waiting for it to arrive. At $1.20 delivered for 3 copies who can complain.

So many great features here and is one of the main reasons I purchased autoquad - absolutely fantastic work Menno!
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Any chance to get Spektrum telemetry too?

Postby aBUGSworstnightmare » Sun Mar 16, 2014 9:08 am

Hi Menno,

impressive work! Well done!

Too bad that I'm one of those Spektrum users out there. Any chance to get native Spectrum telemetry from the AQ6 (we have a free-to-use I2C on board) or to have it bridged from your HOTT telemetry (on the external Mav2HoTT / LED / CAN board)?

I've collected some links dealing with Spektrum telemetry: ... ry-bridge/
This guy is bridging Mavlink from an APM to Spektrum. Shouldn't be to complicated for you to add this functionality to the existing software running on your Mav2Hott Board.
Most of the reverse engineering info on Spektrum telemetry originates from this thread.

some of the (still missing sensor info) is here

Since the pro Mini/Micro's I2C interface is free to use on the Mav2Hott board the external solution could still be useful for all the spektrum guys (besides signaling only when Hott comes natively from the AQ6).

What do you think?
I will have the TM1000 telemetry with (at the moment) external GPS and capacity Sensor (bought one of those on my CamCruiser and I could aid you in testing (and maybe coding) the telemetry stuff.
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Re: AutoQuad native Graupner HoTT telemetry

Postby joebar.rc » Sun Mar 16, 2014 2:39 pm

Ho Joerg,

Have to read all the stuff you posted, cannot comment yet on it :) My most used transmitter is a JR DXM-9 (spektrum) but from the pre-telemetry era so I don''t have HW that is usable. Have to see if it is straightforward to develop..
At least the interface is i2c and no slow bitbanging uart on the arduino.

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