|
Electronics | Audio | NAV | Infotainment Anything related to in-car electronics, navigation, and infotainment. |
|
Thread Tools | Search this Thread |
08-23-2012, 01:06 PM | #1 |
Senior Member
Join Date: Jul 2012
Drives: 2013 Subaru BRZ Limited in WRB
Location: Wilmington, DE
Posts: 204
Thanks: 17
Thanked 86 Times in 48 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
BRZ Steering Wheel Radio Controls
Not for the faint of heart but I'm an electrical engineer so what do you expect...
I know the radio is within arms reach but I do miss my steering wheel radio controls. So, call me crazy but my intention is to use the cruise control stalk on the steering column to change presets and activate voice command. The cruise control is a resistor ladder (single wire) whose reference voltage changes based on the switch position. Looks like the ECU reference is 5V but the factory radio is 3.3V. I'm going to build a simple circuit to convert 0-5V reference signals into the appropriate 3.3V signals for the radio. The circuit will be enabled/disabled based on if the cruise control is on. If the cruise is off, the movements of the cruise control lever will control the radio, if the cruise control is on then the movements will have no affect on the radio. Unfortunately this signal comes from the car's CAN network and I'll have to go after the LED in the cluster ...ugh... I'm not sure if it switches voltage or ground so the "Cruise Control Indicator Light" input -> decoder circuit should be taken with a grain of salt - I have to test at the cluster. I could simply use an ADC chip (like the ADC0804) but I don't have one. I actually have some various ICs just laying around that I can use for it. They're actually quite common (with the exception of the decoder) so I went ahead and put a circuit together. LM7805 - 5V Regulator LM339 - 4 Channel Comparator 74HC154 - 4-16 Decoder Various resistors and transistors I bench tested the circuit below but haven't tried it in the car: The circuit below is outdated and won't work - I have to update the schematic
__________________
Last edited by rmjjensen; 08-24-2012 at 10:04 AM. |
The Following User Says Thank You to rmjjensen For This Useful Post: | nalc (05-31-2013) |
08-24-2012, 10:09 AM | #2 |
Senior Member
Join Date: Jul 2012
Drives: 2013 Subaru BRZ Limited in WRB
Location: Wilmington, DE
Posts: 204
Thanks: 17
Thanked 86 Times in 48 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
I had to make some changes but it works very well. Still have to check the cruise control LED to toggle the circuit but the concept works well.
Check out the video: [ame="http://www.youtube.com/watch?v=smOvIYsp_xc"]Subaru BRZ Steering Wheel Radio Controls - YouTube[/ame]
__________________
|
08-24-2012, 10:16 AM | #3 |
Senior Member
Join Date: Apr 2012
Drives: Limited WRB AT6 BRZ
Location: Atlanta, Ga
Posts: 371
Thanks: 993
Thanked 86 Times in 59 Posts
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
|
Nice work!
|
08-24-2012, 10:47 AM | #4 |
Senior Member
Join Date: Dec 2011
Drives: Kia Stinger GT2
Location: Central NJ
Posts: 524
Thanks: 76
Thanked 157 Times in 107 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
Impressive but it looks like a lot of work for the minor convenience. Where do you intend to mount the control board?
Does nobody make a bluetooth controller that can be wired and mounted to the back of the wheel or something? |
08-24-2012, 11:04 AM | #5 |
Senior Member
Join Date: Feb 2012
Drives: 2013 DGM Subaru BRZ (Subie #9)
Location: ATL, US
Posts: 2,667
Thanks: 123
Thanked 860 Times in 552 Posts
Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
|
The 2012 STi has the same Nav unit and steering wheel controls, but my guess is the BRZ harness does not have any provisions for them. The radio likely does however just like it supports a reverse camera.
I wonder if you could swap in an STi steering wheel and then wire things up. It's a cool project, but I am fine with no controls on the steering wheel. |
08-24-2012, 11:13 AM | #6 |
First 8600
Join Date: Jan 2012
Drives: Darth Raven
Location: Windy City
Posts: 224
Thanks: 5
Thanked 117 Times in 72 Posts
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
|
So does the Pause/Play button on the head unit engage the cruise control and the volume up/down set the speed?
|
09-17-2012, 09:20 AM | #7 | |
Senior Member
Join Date: Aug 2012
Drives: 4Runner
Location: N. Utah
Posts: 1,148
Thanks: 681
Thanked 391 Times in 251 Posts
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
|
Quote:
__________________
diirk
waiting on a Neptune Premium MT |
|
05-31-2013, 05:18 PM | #8 |
Senior Member
Join Date: Apr 2013
Drives: 13 BRZ Limited 6MT GBS
Location: Pennsylvania
Posts: 415
Thanks: 181
Thanked 256 Times in 130 Posts
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
|
Is there a corrected schematic?
How did you figure out the radio pins? It looks like the head unit only uses one pin for controls, so it's got to be looking for some type of signal or a different resistance or something like that to differentiate between the different buttons, rather than just shorting that pin to another, right? I've been digging for info about it, but I haven't been able to figure out what kind of signal you need to put on that pin for each desired function. I haven't been able to find an interface control document for the head unit. If I'm guessing correctly (I'm not a sparky like you are), you're using that voltage divider in the upper left to send different voltages to pin 21 for different functions, i.e. 2.5v is next track, 1.5v is previous track, something like that? I'd be happy enough if I could figure out a way to rig up some momentary switches to function as previous/next radio switches. Your work on this is very impressive.
__________________
|
06-03-2013, 12:39 AM | #9 |
the tuna, no crust.
Join Date: Oct 2012
Drives: 2014 Hachiroku of the year
Location: jersey
Posts: 2,298
Thanks: 874
Thanked 1,770 Times in 761 Posts
Mentioned: 78 Post(s)
Tagged: 0 Thread(s)
|
DUDE.
this is what i've been dying to have is steering wheel controls. any way to make it possible to adjust volume? if you can make something that we can wire in ourselves and say what you need to tap etc etc i'll gladly shell out some $ to do this. |
06-03-2013, 04:22 AM | #10 |
Senior Member
Join Date: Jan 2013
Drives: '13 DGM BRZ Limited/'14 Yamaha R6
Location: SoFlo
Posts: 333
Thanks: 46
Thanked 96 Times in 64 Posts
Mentioned: 2 Post(s)
Tagged: 2 Thread(s)
|
I know a lot of people don't like steering wheel controls and say the radio is right there, etc. Those people must not change songs/stations much on the BRZ HU. Touch screens are bad enough for simple controls, but this one is one of the worst touch screens. I just want a "Next" button that I don't have to look at at the right angle to touch.
|
06-03-2013, 08:11 AM | #11 | |||||
Senior Member
Join Date: Jul 2012
Drives: 2013 Subaru BRZ Limited in WRB
Location: Wilmington, DE
Posts: 204
Thanks: 17
Thanked 86 Times in 48 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Quote:
The radio pins are the same pins used for the WRX. The schematic has them labeled as pin 21 and 22. Each pin has multiple functions so the connection you make would depend on the function you want to control. You can test the functions easily with a couple of resistors between pin 21 (or 22) and ground. Quote:
Quote:
Quote:
I never thought about producing this since the original thread got absolutely 0 traction so I stop contributing. Quote:
__________________
|
|||||
The Following User Says Thank You to rmjjensen For This Useful Post: | nalc (06-03-2013) |
06-03-2013, 08:41 AM | #12 |
Senior Member
Join Date: Apr 2013
Drives: 13 BRZ Limited 6MT GBS
Location: Pennsylvania
Posts: 415
Thanks: 181
Thanked 256 Times in 130 Posts
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
|
Hmmm, thanks for the guidance. I mostly just want to get previous/next radio preset. Volume's not a huge deal because there's a tactile knob not that far away, but the biggest desire is to operate the radio without looking, something I can't do now with having to line my finger up with a 1/4"x1/2" little soft button located not at the edge of the screen.
What ballpark am I shooting in with resistor values? I see a lot of 1K stuff. Once I have some time to mess around, I think I will order a 10k linear taper pot, a momentary switch, and the appropriate radio connector, and see if I can get a table of what each resistance does. Then I was thinking of whipping up a simple project box with a number of momentary switches, and perhaps sticking it on the blank cover where the key would have gone if I didn't have a Limited, as that area is readily accessible, currently unused, and a little out of sight.
__________________
|
06-03-2013, 09:29 AM | #13 |
Senior Member
Join Date: Mar 2013
Drives: 2013 DGM BRZ, 2020 C8 Corvette
Location: USofA!
Posts: 1,760
Thanks: 963
Thanked 1,893 Times in 787 Posts
Mentioned: 41 Post(s)
Tagged: 1 Thread(s)
|
if the BRZ steering wheel were swapped out with an STi one, would that work? (albeit more expensive)
steering wheel radio controls is something i do miss on the BRZ, which i have on my outback. off topic, but i also wonder why the BRZ didn't come equipped with the same sharkfin antenna that comes on the outback. they both have the same function - nav, xmradio etc. |
06-03-2013, 10:11 AM | #14 | |
Cone basher
Join Date: Mar 2012
Drives: 2017 Subaru BRZ Series.Yellow
Location: Dodgin cones in San Antonio, TX
Posts: 800
Thanks: 51
Thanked 256 Times in 169 Posts
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
|
Quote:
|
|
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
steering wheel controls | inimitable | BRZ First-Gen (2012+) -- General Topics | 79 | 09-05-2016 12:56 AM |
Steering wheel radio controls | brillo | Electronics | Audio | NAV | Infotainment | 6 | 12-26-2014 10:03 PM |
What happened to steering wheel-mounted controls? | Stu L Tissimus | BRZ First-Gen (2012+) -- General Topics | 31 | 07-19-2012 03:52 PM |
Steering wheel controls / Stock Player? | StevenDavisPhoto | Electronics | Audio | NAV | Infotainment | 7 | 01-27-2012 03:18 PM |
That steering wheel | poormans_LFA | Scion FR-S / Toyota 86 GT86 General Forum | 26 | 12-04-2011 12:16 AM |