I found I had Left and Right Pre outputs that sum the two left channels and two right channels before the level-control (non fading outputs) on the Alpine AMP. These summed Pre Outs now feed the MT107A speaker sample inputs instead of using my (temp get it going in a hurry) isolation transformer and resistive divider that was connected to one of the speakers.
I just finished testing this final connection with a few calls to mobile and landline phones running hands-free. If I unplug the speaker sample lead, the other phones hear so much return echo that it’s almost impossible for them to have a conversation with me, plug the sample lead back in and there is absolutely ZERO echo, even with the volume level in the car wound “way way up”, the MT107A is a brilliant device :rock:
For anyone wanting to get their hands dirty (some programming required) and looking for a dedicated Vehicle GPS tracking, Phone, Internet, Video Surveillance/Recording to SD card and PC, along with the possibility of a remote Vehicle control solution that can be controlled via Serial commands. There is a 3G Phone, GPS and NET, Video unit available with prices varying from expensive ($250) down to around $90 depending on what and where. They also have a unit for the Arduino and a few notes on that are listed below. These units are based on the SIMCOM SIM5218 module which handles all of the above.
The 3G shield for Arduino enables connection to high-speed WCDMA and HSPA cellular. The module features an internal GPS that enables indoor and outdoor geo-location, combining standard NMEA frames with mobile cell ID triangulation using both assisted-mobile (A-GPS) and mobile-based (S-GPS) modes.
You can also use this board as a standard 3G modem at full speed (~7.2Mbps download, ~5.5Mbps upload) by connecting it via its mini-USB socket to your laptop (Linux, Windows, Mac-OS).
This A/V Kit version features the board plus a 2GB micro-SD card, an electret microphone, a VGA CMOS camera, 65 M/F jumper wires of varying length, a 2W/8Ω speaker, hands-free headphones/microphone, a mini-USB cable, and an internal speaker.
The module is designed to work with Internet servers directly (without having to go through the Arduino), internally implementing several application layer protocols which make it easier to send the information to the cloud. This means you will control the action from the main program running on the Arduino, though the data may flow from the 3G module to the SD card or from the video camera to the 3G module, without a UART bottleneck. You can make HTTP and HTTPS (secure mode) navigation, downloading and uploading content to a web server. Likewise, FTP and FTPS (secure mode) protocols are available, which is useful when your application requires handling files. You can even send and receive email directly from Arduino using the SMTP and POP3 clients implemented internally.
With the SD Card socket, you can handle a complete FAT16 file system and store up to 32GB of information. This is especially useful as the 3G module can work at full speed (~7.2Mbps download, ~5.5Mbps upload) when working with the SD files directly without need of the Arduino for data or file management.
Some changes to Touch Screen and Encoder Push button control. In an effort to make the control of an integrated CAR-PC solution as easy to use and the least distracting for the driver, I have changed the double press action of the touch screen buttons and the encoder push buttons. I guess Iím behind the times here as I wrote everything from scratch without any preconceived ideas and this control is most likely already implemented in most Front Ends (yes I know itís in smart phones).
I have long used a double click action to bring up option menus for the GPS, Phone, Radio, Camera and Music systems along with a double push control for options via the Manual controls in the centre console. I have changed these to a long single touch or push of around 1 second.
The result is the complete elimination of false touch or control push actions and a surprisingly big improvement in any distraction caused by the old double click action in a Vehicle on bumpy and undulating roads. Touch screen feel is a 100% improvement as the option menu or screen pops up on the longer touch timeout. Simple things some of us (me) overlook, sigh! :doh:
simply amazing work Mickz! as an EE and HW guy to boot (mostly FPGAs), I can personally appreciate the hard work, research, time and money spent on your design and implementation... you would be an asset to any company you worked for.
I have a 2003 Accord EX-L with the dual zone climate controls and the integrated radio/HVAC is my only true dislike. I have the Dension iPod adapter right now.
I don't have the time, money or patience to tackle something like this, although I do think it would be fun to implement the micro-controllers and such inside an FPGA.
I recently came up with a (crazy) notion to use the Climate control from the 03 - 08 Pilots in my Accord in order to keep the advanced auto functionality (minus the dual zone part). It's a single DIN size I believe (just eyeballing the one in my wife's Pilot/on ebay). I figured I could modify the Metra dual zone to single zone cable to work with the Pilot unit. at this point its only an idea as I haven't compared wiring diagrams or connector pinouts, but, it might be a simpler alternative for those following your work who could live without the climate controls on their car pc screens.
again, awesome work. I always look forward to browsing through your threads.
thrakkor, thanks for the words, really appreciated.
The Microprocessor parts cost was only around $80, the labour! well, thatís another story, but as itís a hobby that doesnít count for me.
Your idea is actually good but I believe there is a ďSMALLĒ DUAL ZONE HVAC control board in the Honda Acura of similar years. I think the NAV version of the ACCORD may have a small separate HVAC control and I know it has a separate TEMP and control indicator display. That may be worth looking at. I canít get any of that over here.
As far as the standard Accord goes, itís not hard to move that BIG HAVC CONTROL PCB to beneath the passenger seat. Only problem is a TEMP/Control display, I had coded a micro to drive a SMALL LCD (NO car PC needed) but went no further with it.
Best of luck with any project you undertake and thanks again for the encouraging feedback.
Another small update, I tried a program called Breakaway which was first introduced here.
Itís in the MP3 store. Breakaway_Audio_Enhancer_Downloadable_Software
The problem with multiple sound sources (especially in a vehicle) is keeping the volume at a fairly constant level as the sound source is changed, then I have the problem of widely varying sound levels between hundreds of MP3 and other music formats, and the different levels between DAB station, FM radio station, the Phone, Menu voice announcements, GPS and on and on it goes.
My main interest in this software was its look ahead buffers with real time volume levelling capabilities. I donít know what changes may have been made in the release I downloaded but I was able to redirect Line Input for the DAB-FM radio module and MIC input for the Phone RX audio through the Virtual soundcard created by the software without any problems.
I was able to adjust the various input levels correctly as before and once done, all sound sources are now equal and they stay that way. No more adjusting the volume for loud or soft Audio files and as the peaks are limited there no sudden ear splitting mishaps.
As if that wasnít enough, I concur with others, the improvement in sound quality, especially in a noisy environment like a vehicle at speed is amazing.
Worth every cent of the $18 odd dollars and you can try it for 30 days free to see if it fits your needs.
Thatís about the last piece of the puzzle for the sound system completed.
NOTE: I have read about people having a problem with controlling the master volume in RR and other FE applications with this SW installed. I donít know if that has been resolved, so I must point out again that I donít control the Windows mixer for overall volume. Steering wheel volume controls and the Master volume control, located in the centre console between the front seats, both control the volume level via my FE at a point between the DA convertor and the AMP.
Well, Iím still on the subject of Breakaway software, I know, big Yawn.
Although there havenít been any SW updates since around 2009 (judging by the Breakaway forums) this version reportedly works with Win 8 and has been 100% trouble free in both of my systems. I went browsing for info on the design of this software and found enough to validate my impression of its high quality. Anyway I find I canít do without it on my Home PC either. Although the controls look deceptively simple, what is happening below the surface is very complex with good scope to tailor the sound balance and volume levelling algorithm etc.
The main reason for this update: I have only now had a chance to test Breakaway on a Phone call. I was expecting problems with feedback and noise as Breakaway SW tried to bring the incoming phone call audio level and frequency response up to the system level.
Man, I was absolutely blown away by the huge improvement in Phone audio, both quality and level. I would now rate this as a must have piece of SW for that reason alone.
There is a noise reduction option in Breakaway, I thought this was just a simple type of level mute but it appears to be a lot more intelligent than that. Now why would I want that if I have (had) a noise free system? Answer: The inbuilt Phone module!
The audio path from the phone Module required quite a bit of gain and as the module is mounted very close to the aerial (to keep RF transmission losses down) it requires a 2m lead back to the PC for audio input. Add the Modules USB connection and 12v input and that resulted in a very slight noise which is only audible when the Vehicle motor is off and no other Audio source is playing, IE silence. Breakaway will also argument this noise (slightly) as it raises the gain path in the absence of other inputs.
So who cares! Well, itís surprising how annoying that slight noise can be as, like a lot of you, I tend to focus on any imperfection in the installation.
Switching Breakaways Noise reduction ON simply removes this noise and results in no change whatsoever to playback Audio quality, to my surprise it also greatly reduced other types of background noises from the Phone call audio itself.
Late EDIT- UPDATE:
Just on the subject of the Noise Limiter. Testing indicates that this is a ďMulti BandĒ noise limiter with up to 7 Bands available. IMHO this is why I have such a big improvement in Phone Audio.
Phone audio is mostly Voice frequencies and usually narrow bandwidth; however the noise generated in the Vehicle Phone audio path is wide band. During a Phone call, the noise limiter is removing noise from the audio bands that donít contain, or contain very little speech, and thereby making a huge improvement in Phone audio clarity. IE increasing the voice level via AGC action, boosting the mid band response via intelligent Equalisation and reducing out of ďvoice bandĒ noise.
I posted to a thread on LED backlight here: http://Lcd-displaycontrolling-back-lights-directly
This is the main info I posted:
I was reminded about looking at my LED backlighting once again. I just now popped the monitor from the vehicle and was surprised to find that this monitor does indeed adjust LED backlighting. However it’s only a 3 step adjustment for Bright, Normal and Dark and is automatically controlled via a small Photo Diode. It’s a PWM control from a small separate PCB labelled “funnily enough” LED DRV.
This PCB has normal 2 wires running to the LED array and another small 4 pin connector. The 4 pins were earth, +5v, +5v and the other varied from 0.4 volts to 1.2 volts in response to the Light detector circuit on the Main PCB. Quick test and I found I could get the LED backlight to go way down in brightness with 1.8 volts (normally 1.2V at Dark setting) on that pin and brightness variation was linear with voltage from 0.4 to 1.8V.
I’ll see about either dropping the Vehicle PWM control line down to match this variation with a resistive divider or just play it completely safe and use a $1.50 Optocoupler for a totally isolated connection. In either case I’ll gate the existing 3 step Auto control (it’s handy for day use) and have the Vehicle PWM control signal switch in with Vehicle lights.
Total display consumption @ 12V is 6 Watts with bright and around 2 Watts dim backlight.
I have traced out the circuit for the LED Backlight Control. The IC appears to be a small (SMD) 6 pin Step-up convertor. The current through the LEDs is sensed and SET by parallel connected resistors 2R2, 4R7. With this layout I would assume overvoltage protection, open circuit protection, over current protection etc.
Interesting Note: This monitor also adjusts the Brightness and Contrast levels along with the Backlight level with the 3 Step Ambient light sense circuit located on the Main PCB.
My FE reads the PWM dash-light signal from the Vehicle and adjusts the Windows Brightness level, this works great in conjunction with the Auto Backlight on the Monitor – however it is STILL not quite enough for country night driving and this is where further reduction of the LED backlight will make a big difference. My initial interest in Backlight control was the hope it would maintain good contrast and color depth at low output levels, which is not always the case with trying to bring Brightness and Contrast way down with normal controls and the Windows API.
Test carried out last night appear to indicate this is a far superior method and I had really good color and contrast with the LED backlight wound way down.
I’m currently trawling the NET trying to find an IC/circuit similar to this. There are some very complicated LED backlight driving schemes out there but mainly for large screen devices, haven’t found anything much like this as yet.
I'm HAPPY - I may have found something dam close! That line I labelled as a possible Enable is more than that as it can be driven with a PWM signal for BL control. This circuit even has the DC control of BL intensity (as in my unit) and the possibility of PWM control via the FB pin as well.
And here is the PDF I managed to find which is close to this device and circuit.
Note: My unit is in fact PWM and not DC on the FB control input. But DC control worked perfectly, after the filter (C5 and input resistor) PWM would likely be a DC voltage anyway.
Well, I’ve modified the unit for direct control of the LED backlight by the Vehicle dash-light PWM signal. The PWM control in this Vehicle is a 200HZ PWM square wave running at 10v Peak.
Dash-light control full brightness: PWM stops and Line drops to 0 volts.
Dash-light control 90% brightness: PWM around 10% on 90% off
Dash-light control 50% brightness: PWM 50% (1:1) or 50% on 50% off
Dash-light control fully dimmed: PWM around 90% on 10% off
This is of course the opposite to what is needed to Drive the Enable/low freq PWM line. IE +5v is applied by the current LCD controller for full Brightness (Enabled) and 0V is off (Disabled).
However, it is absolutely perfect for allowing me to keep the existing Enable control from the LCD PCB which is used to turn the Backlight off when no video is present.
The modification required one NPN transistor to invert the waveform and 3 resistors. Two resistors are used to drop the 10v PWM down to the correct voltage to drive the transistor and the 3rd resistor (2k2) is used as the load resistor between the existing +5V Enable Line and the collector of the transistor. Almost no way to damage the LCD or controller this way as the only connection is via a 22k resistor.
So, dash-lights OFF = no voltage to the transistor, so it’s switched off and as before, the Enable line is controlled by the LCD main PCB. Dash-lights ON and the PWM signal controls the Backlight, the Enable Line can still kill the Backlight in the absence of Video or in standby.
I have left the existing backlight control from the LCD Main PCB as they work perfectly together.
Just tried it in the Vehicle and its perfect!
I carried out a few more tests in the Vehicle and the results are as follows:
1. With the LCD backlight controlled by the vehicle dash-light, which is controlling the modified PWM input, AND also using the LED 3 step Backlight control built into the Monitor, the result is “almost” perfect in a pitch black location with no annoying GLOW effect.
With only that control, normal driving with streetlights and other vehicles would be perfect.
2. In complete darkness IE No street lights or other vehicle headlights - night time country driving.
With 1 (above) and the FE ALSO controlling the Windows brightness via the API, as most FE application seem to do, the extra reduction in brightness results in a perfect display, again without that annoying GLOW effect from my normally half lit backlight. I can only imagine how annoying a full lit backlight would be in an 8” screen that’s not far below eye level.
Finally, if you have a monitor that doesn’t control LED Backlighting, and it seem there are a lot that don’t, then the effect will be even more dramatic. At least my unit dropped the backlight to 50% at night, but as I said, it was still a bit annoying in really dark driving conditions, now its perfect :rock:
Just to clarify a few things here.
I have been reading through some of the old threads on LED Backlighting control and the means used to attempt to control them. So here are a few points to consider when using this circuit.
1. May already be inside your Monitor and only needs a simple mod for external control.
2. The circuit can be controlled by either a PWM signal or a variable DC voltage.
3. The voltage across the LEDs is DC when the IC is controlled with a DC voltage via the FB pin.
4. The voltage across the LEDs is of course PWM when the IC is driven with a PWM signal via the Enable pin.
5. Can be driven straight from a Microcontroller with PWM into the Enable pin.
6. Parts don’t have to be SMD (except for the IC) but that is only a 6 pin device and the spacing is pretty reasonable, soldering with a fine tip iron would be relatively easy if you have soldered before.
7. No heat-sink required and very small size.
8. Can be interfaced to the existing Vehicle PWM line with minimal effort and $1.60 in parts.
Anyone having trouble understanding what’s being done here or wants a little clarification, please don’t be hesitant in asking, I’ll help wherever I can.