10-28-2023, 04:44 AM
Just wanted to say THANK YOU for this slice of Pi. I am building a retromod for my 1994 Acura Vigor GS 5MT using the Wavetech 5.5" AMOLED screen and a Pi 4 with Open Auto and your carPiHat Pro (DAC) with shroud and fan board. This little screen set up will allow the Pi to integrate behind a 5.5" 1999-2003 Acura TL/CL Navigation panel and look 100% OEM, just now with Android Auto! It's exactly what I want and the aftermarket stereo market doesn't make anything that comes remotely close to this besides the horrible Chinese AndroidAuto motorcycle units. A few years ago I was going to use a only LG G5 phone but didn't want to risk the battery burning the car down.
Overall set up was a pain on my part for being 100% new to code, Pi/Linux operations on top of using one of the most finicky displays for the Pi (selected for the screen size).
I'm about 70% finished with the build but have a few questions if you don't mind.
1.) Do you have any audio output specifications from the Burr-Brown DAC used on your board? I would love to know the voltage output, sensitivity to noise, freq range etc, to help pair it to my amplifier. The audio output will be fed through a factory Acura radio (aux in) for mostly volume control, but also FM tuner and CD functions on the rare occasion I may opt. This head unit is a PRE AMP ONLY with basic Treble and Bass tuning and very little internal equalization/ DSP, it's output voltage is less than 6v as it has no internal amplifier. It would essentially be a pass through to my 5 channel amp. I am not worried about the OEM head unit as much as I am curious if your DAC will provide ample input signal strength for adequate volume without having to increase the gain on my amp so knowing the output voltage would be helpful. I am listening to the DAC currently via android auto connection and some Sony earphones, the sound is clear and has a decent volume. The built in equalizer works but is a little exaggerated.
2.) I had a hard time understanding your Quick Start guide for the carPiHat, it took me forever to get the 12v ACC switch shut down to work, that is my fault. However I notice that after the 12v switch is removed in then reconnected before the timer shuts down the Pi it causes it to abruptly hard reboot. Being such a n00b I don't know if this is how you intended its operation or if I have something wrong with the python script but it seems harsh. I would actually LOVE to have the Pi go into hibernation/sleep immediately (audio, screen, fan turn off) when the 12v ACC switch is removed but not shut down until after 5 or 10 minutes of the 12v ACC not being reconnected. That way if I park and shut the car off to run into the store quickly and come back within 10 minutes the Pi wouldn't need to reboot completely, instead just wake up and resume Android Auto. My boot times are around 20 seconds with an SSD so it's not horrible to head with, but can this be implemented?
3.) I don't plan on using any extras besides a light sensor to adjust screen brightness, but I am intrigued by the BCM13 Illumination input. Is this an input of 12v from the car to trigger screen dimming or day/night mode, or is this a 12v OUTPUT to turn on accessory lighting? I don't see any code/script to enable this mentioned in the Quick Start. I have a set of dummy unused buttons on the OEM Acura Navi that I want to illuminate to complete the OEM+ look.
Besides those three things all I have left to do is structurally mount the unit inside the original navigation box making sure the screen is evenly places behind the bezel. I can't wait to install it and enjoy the retro OEM+ look. I have got to figure out a fix to the boot screen static and orientation though, I believe it to be an issue with the Waveshare supplied 180 HDMI board or the timings in the boot config.
Link to video demonstrating ACC power issue:
https://www.youtube.com/watch?v=BI3P1kvIb6M
The original idea with cellphone:
Overall set up was a pain on my part for being 100% new to code, Pi/Linux operations on top of using one of the most finicky displays for the Pi (selected for the screen size).
I'm about 70% finished with the build but have a few questions if you don't mind.
1.) Do you have any audio output specifications from the Burr-Brown DAC used on your board? I would love to know the voltage output, sensitivity to noise, freq range etc, to help pair it to my amplifier. The audio output will be fed through a factory Acura radio (aux in) for mostly volume control, but also FM tuner and CD functions on the rare occasion I may opt. This head unit is a PRE AMP ONLY with basic Treble and Bass tuning and very little internal equalization/ DSP, it's output voltage is less than 6v as it has no internal amplifier. It would essentially be a pass through to my 5 channel amp. I am not worried about the OEM head unit as much as I am curious if your DAC will provide ample input signal strength for adequate volume without having to increase the gain on my amp so knowing the output voltage would be helpful. I am listening to the DAC currently via android auto connection and some Sony earphones, the sound is clear and has a decent volume. The built in equalizer works but is a little exaggerated.
2.) I had a hard time understanding your Quick Start guide for the carPiHat, it took me forever to get the 12v ACC switch shut down to work, that is my fault. However I notice that after the 12v switch is removed in then reconnected before the timer shuts down the Pi it causes it to abruptly hard reboot. Being such a n00b I don't know if this is how you intended its operation or if I have something wrong with the python script but it seems harsh. I would actually LOVE to have the Pi go into hibernation/sleep immediately (audio, screen, fan turn off) when the 12v ACC switch is removed but not shut down until after 5 or 10 minutes of the 12v ACC not being reconnected. That way if I park and shut the car off to run into the store quickly and come back within 10 minutes the Pi wouldn't need to reboot completely, instead just wake up and resume Android Auto. My boot times are around 20 seconds with an SSD so it's not horrible to head with, but can this be implemented?
3.) I don't plan on using any extras besides a light sensor to adjust screen brightness, but I am intrigued by the BCM13 Illumination input. Is this an input of 12v from the car to trigger screen dimming or day/night mode, or is this a 12v OUTPUT to turn on accessory lighting? I don't see any code/script to enable this mentioned in the Quick Start. I have a set of dummy unused buttons on the OEM Acura Navi that I want to illuminate to complete the OEM+ look.
Besides those three things all I have left to do is structurally mount the unit inside the original navigation box making sure the screen is evenly places behind the bezel. I can't wait to install it and enjoy the retro OEM+ look. I have got to figure out a fix to the boot screen static and orientation though, I believe it to be an issue with the Waveshare supplied 180 HDMI board or the timings in the boot config.
Link to video demonstrating ACC power issue:
https://www.youtube.com/watch?v=BI3P1kvIb6M
The original idea with cellphone: