HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Aug 02, 2013, 03:13 PM
Registered User
Romania, Dolj, Craiova
Joined Sep 2007
14,950 Posts
Taranis don't use pots, sensu stricto, they are angular rotation sensors, same used in Futaba radios, so next level are hall or other magnetic or optic sensors, as Jeti.
renatoa is offline Find More Posts by renatoa
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 02, 2013, 03:24 PM
Registered User
LittleMo's Avatar
United States, VA
Joined Dec 2006
1,490 Posts
They are potentiometers (aka adjustable voltage divider; aka variable resistor, etc). Hence "pots". Angular rotation sensors on the other hand may or may not be potentiometers.
LittleMo is offline Find More Posts by LittleMo
Reply With Quote
Old Aug 02, 2013, 04:20 PM
Registered User
Romania, Dolj, Craiova
Joined Sep 2007
14,950 Posts
Sure, the output is a variable voltage, but even a hall sensor produce a variable voltage output. Check this guy conversion:
http://openrcforums.com/forum/viewto...p=45405#p45394
renatoa is offline Find More Posts by renatoa
Reply With Quote
Old Aug 02, 2013, 04:35 PM
Registered User
AndreaMontefusco's Avatar
Italy, Lazio, Rome
Joined Dec 2006
19 Posts
Quote:
Originally Posted by renatoa View Post
Sure, the output is a variable voltage, but even a hall sensor produce a variable ....
Not always, there are hall sensors that are true absolute encoders

http://www.ams.com/eng/Products/Magn...sition-Sensors

using such sensors, you need only an i2c in order to read the data.

even Allegro has some interesting product in its catalogue.
AndreaMontefusco is offline Find More Posts by AndreaMontefusco
Reply With Quote
Old Aug 02, 2013, 10:36 PM
12th Pursuit Squadron
TheAeronut's Avatar
Garland, Tx.
Joined Mar 2002
1,111 Posts
The devices in the Taranis gimbal assemblies ARE potentiometers (a trace of resistive material with a movable contact element that traces along and can read the resistance or voltage along the reistive element) that are enhanced with amplifiers to increase the output signal response over a fraction of the potentiometer's full range.

Calling them 'angular rotation sensors' may be correct for their overall function but does not change the fact that the 'angular rotation sensors' used in the Taranis are potentiometers. There are other technologies that can be used for 'angular rotation sensors' such as hall effect sensors or various types if interruptor wheels capable of producing a direct digital representation of the sensor position, but none of these other technologies are used in Taranis. The potentiometer, op-amp enhanced or not is still the cheapest technology available and is used in all but a VERY FEW and VERY EXPENSIVE consumer/hobby radio control systems.

J.P.
TheAeronut is offline Find More Posts by TheAeronut
Reply With Quote
Old Aug 02, 2013, 11:14 PM
better at crashin than buildin
United States, TN, Luttrell
Joined Aug 2012
173 Posts
so we need to do a Hall effect upgrade
Coolpins is offline Find More Posts by Coolpins
Reply With Quote
Old Aug 03, 2013, 12:04 AM
12th Pursuit Squadron
TheAeronut's Avatar
Garland, Tx.
Joined Mar 2002
1,111 Posts
I do find the hall effect mod interesting and may try it sometime, on some radio. Not likely on my Taranis any time soon though.

J.P.
TheAeronut is offline Find More Posts by TheAeronut
Reply With Quote
Old Aug 03, 2013, 08:45 AM
Registered User
LittleMo's Avatar
United States, VA
Joined Dec 2006
1,490 Posts
You would think someone would manufacturer an all-in-one Hall effect sensor in a small potentiometer-like package.

I wonder what happens to Hall senors in the presence of strong EMI or magnets. For example, if near a power station or when using rare earth magnet clips on the radio.
LittleMo is offline Find More Posts by LittleMo
Reply With Quote
Old Aug 03, 2013, 08:50 AM
I don't want to "Switch Now"
pmackenzie's Avatar
Toronto (Don Mills), Canada
Joined Dec 2002
16,754 Posts
There are lots of them, just google "hall effect potentiometer"

http://www.potentiometers.com/select_hall.cfm

Hall sensors will be affected by magnets, but you have to get them quite close to have any effect.
Magnetic fields drop off very fast, and typical AC feilds are much lower than those in close proximity to the magnet in the hall sensor.
Enclosing the sensor in a steel ring would be enough to shield it.

Pat MacKenzie
pmackenzie is online now Find More Posts by pmackenzie
Reply With Quote
Old Aug 04, 2013, 11:55 AM
Proud to eat Kraut ;-)
Julez's Avatar
Germany
Joined Dec 2003
5,327 Posts
Poti change

The stick potis in the Taranis are perfectly fine and adequate for the job. I't just that they were put in an environment that was, how to put it, an unlucky design. If the mechanics don't center correctly, a better poti or hall sensor won't change a thing.

Speaking of potis, i changed the ones at the top of the TX near the switches. I got some ALPS (Japan) with a ratchet, so you feel 18 clicks at 180 rotation. I also used other knobs which are slightly bigger and grippier than the original ones.

Potis:

http://www.ebay.de/itm/15x-Raster-Po...-/300936522056

Knob:

http://www.conrad.de/ce/de/product/183662/

The left 2pos switch was changed for a pushbutton. I plan to make the TX read all telemetry values when I push it. A test worked fine.
Julez is offline Find More Posts by Julez
Last edited by Julez; Aug 05, 2013 at 03:03 PM.
Reply With Quote
Old Aug 04, 2013, 12:02 PM
Proud to eat Kraut ;-)
Julez's Avatar
Germany
Joined Dec 2003
5,327 Posts
Internal antenna mod

Update: Do not perform this mod! I got RSSI warnings as near as 200m. Control was fine though, but normally RSSI warnings should not appear this near!

Update 2: I was told that I soldered the shielding to the other soldering pad the stock antenna was soldered too. If really the left pad was not connected to ground, but only the right one is, this would explain my fairly bad results.

On all my other radios, the antenna sits inside the case. So I did the same thing with my Taranis.
Before unsoldering the original antenna, I placed the RX in the garden shed and in the house some rooms away and noted the RSSI readings.
Then I unsoldered the original antenna.

At first I tried the flexible Quamum antenna from HobbyKing, but it got worse RSSI readings as the original one.

So I soldered on the original antenna and but it in front of the module bay.

Before, I got an RSSI of 37 for the garden shed, and 60 for the house.
Now I got 40 for the shed and 62 for the house.
So at least there's no harm done concerning range.
Julez is offline Find More Posts by Julez
Last edited by Julez; Oct 16, 2013 at 02:05 AM.
Reply With Quote
Old Aug 04, 2013, 12:05 PM
Proud to eat Kraut ;-)
Julez's Avatar
Germany
Joined Dec 2003
5,327 Posts
Eneloop battery for the Taranis

As I like both eneloop cells and long flight times, I made a new 8s battery for my Taranis.

I guess the pictures say it all.

Because people asked:

http://www.ebay.de/itm/1-x-Crimping-...item1c3541ddd3

These are the crimpers I use for the JST connectors. Crimpers for servo connectors won't work as they are too wide.
Julez is offline Find More Posts by Julez
Last edited by Julez; Aug 04, 2013 at 12:38 PM.
Reply With Quote
Old Aug 04, 2013, 12:08 PM
Registered User
Romania, Dolj, Craiova
Joined Sep 2007
14,950 Posts
You are really hard to please
renatoa is offline Find More Posts by renatoa
Reply With Quote
Old Aug 04, 2013, 12:12 PM
60 years of RC flying
Daedalus66's Avatar
Canada, ON, Ottawa
Joined Feb 2006
16,485 Posts
Quote:
Originally Posted by Julez View Post
On all my other radios, the antenna sits inside the case. So I did the same thing with my Taranis.
Before unsoldering the original antenna, I placed the RX in the garden shed and in the house some rooms away and noted the RSSI readings.
Then I unsoldered the original antenna.

At first I tried the flexible Quamum antenna from HobbyKing, but it got worse RSSI readings as the original one.

So I soldered on the original antenna and but it in front of the module bay.

Before, I got an RSSI of 37 for the garden shed, and 60 for the house.
Now I got 40 for the shed and 62 for the house.
So at least there's no harm done concerning range.
Did you test at various Tx orientations to make sure there are no unusual dead spots in the propagation?
Daedalus66 is online now Find More Posts by Daedalus66
Reply With Quote
Old Aug 04, 2013, 12:35 PM
Proud to eat Kraut ;-)
Julez's Avatar
Germany
Joined Dec 2003
5,327 Posts
Quote:
Originally Posted by renatoa View Post
You are really hard to please
I know. I'm a perfectionist by heart. But this pays of in so far as that my stuff never fails.

Next thing to come will be a 3Pos switch for 3 audio volume levels.

Or can the software volume be assigned to a switch via software?

Quote:
Originally Posted by Daedalus66 View Post
Did you test at various Tx orientations to make sure there are no unusual dead spots in the propagation?
Not yet. But I have mounted TX antennas in much more cognested constellations, and it worked out fine.
But I still promise that I won't raise a stink should I encounter RF problems with my mod.
Julez is offline Find More Posts by Julez
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New Product FrSky Taranis - 16 Channels, Full Telemetry, RSSI Rotozuk Radios 36438 Today 09:53 PM
Wanted FrSky Hack module, Flydream Hack or JR module Fentonflyers Aircraft - General - Radio Equipment (FS/W) 5 May 28, 2014 12:33 AM
Question FrSky Taranis - assimilating web info mcshaz Radios 3 Jun 29, 2013 12:06 AM
Discussion is the FrSky Taranis next step after Turnigy 9X 9Ch tormodnt Radios 2 May 20, 2013 12:37 PM