4 ms·

I really wish there were more beginner developer friendly diy options for car entertainment. I’ve been considering making a carputer out of a raspberry pi, howe

by tW4r 6y ago

I really wish there were more beginner developer friendly diy options for car entertainment. I’ve been considering making a carputer out of a raspberry pi, however, half the solutions are proprietary (looking at Qt), however there were some demos of this running on an rpi. So that is a nice development. I’d rather just put a normal Linux distro there, however, I’m not feeling like waiting 8 seconds every time I turn in my car. Apple CarPlay is in the same boat requiring an MFi private certificate, and no way to provision a short lived cert like they do for iPhones.

detaro 6y ago
which "proprietary" bits of Qt do you think you'd need? There isn't much that's not LGPL or GPL - and while the safety renderer could have automotive applications, you wouldn't care about it for a DIY entertainment system.
mschuster91 6y ago
> I’d rather just put a normal Linux distro there, however, I’m not feeling like waiting 8 seconds every time I turn in my car. Suspend-to-RAM works decently to avoid this, and to avoid it sucking the battery dry, Suspend-to-Flash can be used. Yes this will take some time for restoring RAM... but again, to avoid the user noticing that time, why not start the wakeup process when the user unlocks their car / opens a door?
- ColeyG 6y ago
  Do you have any resources or guides on how to get suspend to ram working?
  - mschuster91 6y ago
    Arch Linux has a decent guide explaining the behind-the-scenes stuff: https://wiki.archlinux.org/index.php/Power_management/Suspend_and_hibernate https://wiki.archlinux.org/index.php/Power_management/Suspen... On desktops and laptops, it Usually Should Just Work (tm). The general culprits for issues are proprietary graphics and wifi drivers as well as shoddy BIOSes with broken ACPI tables, but I never had to dig this deep. For embedded systems, the situation is more complex, as the chipset needs to support it - suspend itself is not the problem in most cases, but wakeup is - for example, the Raspberry Pi does not have a dedicated interrupt (https://github.com/raspberrypi/linux/issues/1281 https://github.com/raspberrypi/linux/issues/1281). If you're working with an embedded chipset, your best bet is the manufacturer, they have to deal with that in the BSP.
  - stragies 6y ago
    Whenever I read comments like this, I think "Why is he trying to use a 10+ years old Ubuntu, or similar"? Or do I just make way luckier buying choices? Suspend to anything has worked flawlessly out of the box for my devices since 10+ years. Do you have a specific example of what is not an "obviously bad hardware combination choice", but yet still does not correctly support Suspend-to-RAM?
    - jcelerier 6y ago
      > Suspend to anything has worked flawlessly out of the box for my devices since 10+ years. lucky you - I have a laptop (GS65) where suspend-to-ram occasionally fails to unsuspend, even on windows
jcelerier 6y ago
> however, half the solutions are proprietary (looking at Qt) if Tesla could write their UI stack with the LGPL version of Qt, likely you can do so too (https://soylentnews.org/article.pl?sid=18/05/20/1737213 https://soylentnews.org/article.pl?sid=18/05/20/1737213)
Sebb767 6y ago
I've been in the same boat. If you really want a hackable infotainment without a TON of work and electrical problems, your best bet is an Android head unit which supports aftermarket OS's. It's not perfect, but you save yourself the headache of getting the CAN Bus working, connecting the Audio, getting the startup right etc etc.
cb22 6y ago
> I’d rather just put a normal Linux distro there, however, I’m not feeling like waiting 8 seconds every time I turn in my car. I've been working on a Pi Zero W based carputer (really, it's headless and just interfaces with my phone over Bluetooth / the existing radio head unit and steering wheel menu and controls). Boot time is probably around ~8 second mark currently (fully booted with buildroot / systemd, it's powered from 12V switched by the key) and it already feels fast enough. I normally start my car, put on my seat belt and look around. By the time I've finished doing that it has connected to my phone. Of course, it would be possible to do even smarter things. Hook up a low power micro that can interface with the CAN bus and a MOSFET, and you can instead power it from the battery and turn it on when the car is unlocked and off after a timeout based on the engine going off.
sneusse 6y ago
You might want to give eCos a try. This should be runnable on a Raspberry. I managed to port Luvit (Luas NodeJS) in a few days. Then you should have a system booting within 500ms. https://ecos.sourceware.org/ https://ecos.sourceware.org/ https://github.com/luvit/luvit https://github.com/luvit/luvit Sadly there is not a really big community around both of these.

by tW4r 6y ago

detaro 6y ago

which "proprietary" bits of Qt do you think you'd need? There isn't much that's not LGPL or GPL - and while the safety renderer could have automotive applications, you wouldn't care about it for a DIY entertainment system.

mschuster91 6y ago

> I’d rather just put a normal Linux distro there, however, I’m not feeling like waiting 8 seconds every time I turn in my car. Suspend-to-RAM works decently to avoid this, and to avoid it sucking the battery dry, Suspend-to-Flash can be used. Yes this will take some time for restoring RAM... but again, to avoid the user noticing that time, why not start the wakeup process when the user unlocks their car / opens a door?

ColeyG 6y ago
Do you have any resources or guides on how to get suspend to ram working?
- mschuster91 6y ago
  Arch Linux has a decent guide explaining the behind-the-scenes stuff: https://wiki.archlinux.org/index.php/Power_management/Suspend_and_hibernate https://wiki.archlinux.org/index.php/Power_management/Suspen... On desktops and laptops, it Usually Should Just Work (tm). The general culprits for issues are proprietary graphics and wifi drivers as well as shoddy BIOSes with broken ACPI tables, but I never had to dig this deep. For embedded systems, the situation is more complex, as the chipset needs to support it - suspend itself is not the problem in most cases, but wakeup is - for example, the Raspberry Pi does not have a dedicated interrupt (https://github.com/raspberrypi/linux/issues/1281 https://github.com/raspberrypi/linux/issues/1281). If you're working with an embedded chipset, your best bet is the manufacturer, they have to deal with that in the BSP.
- stragies 6y ago
  Whenever I read comments like this, I think "Why is he trying to use a 10+ years old Ubuntu, or similar"? Or do I just make way luckier buying choices? Suspend to anything has worked flawlessly out of the box for my devices since 10+ years. Do you have a specific example of what is not an "obviously bad hardware combination choice", but yet still does not correctly support Suspend-to-RAM?
  - jcelerier 6y ago
    > Suspend to anything has worked flawlessly out of the box for my devices since 10+ years. lucky you - I have a laptop (GS65) where suspend-to-ram occasionally fails to unsuspend, even on windows

jcelerier 6y ago

> however, half the solutions are proprietary (looking at Qt) if Tesla could write their UI stack with the LGPL version of Qt, likely you can do so too (https://soylentnews.org/article.pl?sid=18/05/20/1737213 https://soylentnews.org/article.pl?sid=18/05/20/1737213)

Sebb767 6y ago

I've been in the same boat. If you really want a hackable infotainment without a TON of work and electrical problems, your best bet is an Android head unit which supports aftermarket OS's. It's not perfect, but you save yourself the headache of getting the CAN Bus working, connecting the Audio, getting the startup right etc etc.

cb22 6y ago

> I’d rather just put a normal Linux distro there, however, I’m not feeling like waiting 8 seconds every time I turn in my car. I've been working on a Pi Zero W based carputer (really, it's headless and just interfaces with my phone over Bluetooth / the existing radio head unit and steering wheel menu and controls). Boot time is probably around ~8 second mark currently (fully booted with buildroot / systemd, it's powered from 12V switched by the key) and it already feels fast enough. I normally start my car, put on my seat belt and look around. By the time I've finished doing that it has connected to my phone. Of course, it would be possible to do even smarter things. Hook up a low power micro that can interface with the CAN bus and a MOSFET, and you can instead power it from the battery and turn it on when the car is unlocked and off after a timeout based on the engine going off.

sneusse 6y ago

You might want to give eCos a try. This should be runnable on a Raspberry. I managed to port Luvit (Luas NodeJS) in a few days. Then you should have a system booting within 500ms. https://ecos.sourceware.org/ https://ecos.sourceware.org/ https://github.com/luvit/luvit https://github.com/luvit/luvit Sadly there is not a really big community around both of these.