Need help selecting a suitable SBC or similar for my project - Page 1
Forum section: electronics / general

author: aabill
author_rank: Contributor
timestamp: December 10, 2022, 03:51:04 pm
content: HelloMy project is a one-off instrument panel for a kit car using a 12.3" 1920 x 720 display panel. I had intended to run RealDash (https://realdash.net/gallery.phpon latest Raspbian (Debian Bullseye) on a RPI 4B but have hit a deal-breaker snag. I did not know at time of purchase that RPI hardware does not support suspend-to-RAM / resume (or even hibernate to disk). Two alternatives:keep the Pi continuously powered up is no good because when idle it draws 575mA which would too quickly flatten the car batteryswitch off when car not in use is no good because the Pi boot time is too longI am looking at alternative boards but so far all those I have seen which do support suspend / resume do not support 1920 x 720.Thoughts? Does anyone know of a suitable board, or have a useful suggestion...?TIABill A.

author: Nominal Animal
author_rank: Super Contributor
timestamp: December 11, 2022, 03:21:45 pm
content: How aboutOdroid N2Lwith eMMC, based on Amlogic S922X SoC?OrOdroid M1based on Rockchip RK3568 SoC, with an eMMC module?Amlogic, Samsung (Exynos), and Rockchip all push their kernel changes upstream to vanilla kernels, so you're not dependant on what the vendor provides.I do not personally have either, but have been looking at both. I do have some of the older ones (C1+, C2, HC1), and have had no issues in Linux with them, and I am somewhat familiar with both Amlogic SoCs and Mali GPUs.(Specifically, I've been looking at both theN2L 4GBytewith the64GByte eMMC modulefor computation intensive stuff; and theOdroid M1with a16GByte eMMC modulefor media server type stuff.)In particular, the Odroid M1 consumes only 0.06 watts (60mW, 5mA @ 12VDC) when suspended. You will want to use an eMMC module for the core OS, even if you use a SATA SSD or a NVMe/PCIe M.2 2280 SSD card, to reduce boot times by bypassing PetitBoot.For Odroid N2L, the eMMC module will be your boot and storage media, although you can use an USB 3 hard drive (or USB3 to SATA adapter) for external media.While 1920x720 is not a native HDMI mode, it can be supported bysetting the display modeusing acustom HDMI/DVI modeset. You do need the display module timings (or EDID data) to construct a suitable modeline, but that's all.Moreover, you can usedevice tree overlaysusing the same mechanism to set up any SPI, I2C, PWM, or GPIO pins on the2×20 expansion connector on N2LorM1. You also probably want to set a custombootlogo, since that's shown during bootup and wakeup from hibernation.In any case, if you decide to go for an Odroid, do check bothwiki.odroid.comandforum.odroid.comfirst, for the board. Consider even registering, and asking there (on the proper sub-forum, possiblyOdroid M1 > hardware and peripherals) before buying. A link to the display module or its EDID information (timings) will be handy there.A completely different approach would be to use (a custom) Android device instead of a Linux distribution. The TV boxes (using e.g. Rockchip SoCs) have good hardware video decoding, but usually run from a ramdisk, and cannot suspend (due to lack of RAM) or hibernate (due to lack of storage). Some of them boot rather quick, though. Of course, Odroid M1 has images available for both Linux and Android, and you can brew your own for both (although it is quite a steep learning curve; so better start with the provided system images).All things considered, although I'm only a hobbyist who never does automotive stuff, I'd carefully consider Odroid M1, and the 16GByte (or larger) eMMC module.

author: aabill
author_rank: Contributor
timestamp: December 12, 2022, 12:09:02 pm
content: Many thanks for the info and links and suggestions and the trouble you've taken to respond so thoughtfully. I will look into all of it and will report progress here for the benefit of others.Rgds, Bill