[Resolved] Looking for a SBC for a serial based project - Page 1
Forum section: electronics / general

author: AlexJackson
author_rank: Contributor
timestamp: July 19, 2020, 09:52:12 pm
content: I'm moving along with my main project (a"homelab" power monitor), but I'm getting close to the point in which I need to start the front-end hardware. I've been looking at a handful of SBCs and I'm not particular between arm or x86, but I've been looking at the older PC Engines Alix/APU line. I plan on running a basic version of linux (probably debian based as its the only linux know a little about). This device will not need access to the internet, and the only exposed ethernet service is going to be httpd for the user front end.Planned Software stack• Debian• apache/nginx• php7• mariadb (still considering sqlite instead to remove complexity, but it will require more dev testing)Necessary hardware requirements• As much memory as i can get away with• Don't need a ton of CPU, it will mostly sit idle, and it wont be powered down much• 12vdc powered• VGA port• 2 serial ports. (1 external & 1 internal preferred)• storage options other than USB and/or sdcard because of frequent writes• 1 ethernet port• Small size. This is going to be enclosed in a casing (with fans of course), and the smaller the better.I don't need anything insanely powerful. I'm going to be pulling data off the connected serial device every few minutes and saving the data to a database. The web front end will only communicate with the database for the "history" and the local file for the "live readings". No web control panel is planned.Thoughts?Found the Advantech PCM-9365 industrial board.

author: 2N3055
author_rank: Super Contributor
timestamp: July 23, 2020, 02:45:26 pm
content: I second blueskull.

author: AlexJackson
author_rank: Contributor
timestamp: July 27, 2020, 03:26:56 pm
content: Thanks for the replies. In hindsight I can probably get by without the VGA. I'm leaning more toward the rpi route but my biggest concerns are the SD card storage, and being bound by usb. I havent had the best luck with usb in the past and had to constantly powercycle a project weekly because the usb flaked out. Hopefully I'll have less issues this time around. Adding a second serial port will require a usb-serial converter along with a RTC over gpio. This thing will look like it was made by apple with dongles everywhere.I was hoping there was a suitable SBC where I could use more purpose built interfaces (rtc, i2c, spi, 2x rs232, m2 or eMMc, sata, 1x ethernet, etc). But my entire software stack works great as-is on a pi and there is plenty of support... The joys of development huh. :pI do have another pi on its way here *eventually* to replace my aging pi2 acting as pihole.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 27, 2020, 05:34:12 pm
content: One thing the RPi doesn't have is a non-volatile RTC, so it will lose time every time it's shut down. I don't know if there are add-ons for this, because it can be pretty annoying?Of course, if your device is connected to the Internet, you can always use NTP and call it a day.On the RPi4, you can get up to 4GB RAM, it has 2 UARTs actually, one SPI and one I2C IIRC. No M2 port, no eMMC, no sata. But Gigabit ethernet.Armbian is Debian-based.You can get HDMI to VGA adapters for relatively cheap these days (around $20 or less.)

author: AlexJackson
author_rank: Contributor
timestamp: August 02, 2020, 12:23:54 pm
content: Bit of an update on this. I found a board, and its on its way that ticked all the boxes.Advantech PCM 9365(x86) based.I was pricing out boards, options, dongles, etc and managed to see one of these on ebay with accessories, ssd with windows embedded forunder $70(err it was $72). So now I have another pi coming, and now this thing. There was a much older model of this board for $17 to play with but someone snagged it before I did.