Embedded system: Linux, ARM, wifi, rs485? - Page 1
Forum section: electronics / general

author: casper.bang
author_rank: Frequent Contributor
timestamp: August 02, 2013, 03:30:06 pm
content: Short and sweet; what's the cheapest small embedded board capable of running Linux; with an ARM, wifi and rs485? I'm trying to see if there's an alternative to my current approach of using an mk802 Android stick with an USB-rs485 adaptor (around US $60). The problem with the mk802 solution (beyond the fact that I have no need for dual-core, HD output nor Android) is that it's quite tricky to compile FTDI/pl2303 support for the kernel.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 02, 2013, 04:46:36 pm
content: Doubt you'll find RS485 outside of products designed for industrial type apps, and anything with normal UART is unlikely to have enable support to do 485 with a simple driver.USB-RS485 is probably the best solution hardware-wise. Does Linux really not have FTDI support as standard these days..?

author: dr.diesel
author_rank: Super Contributor
timestamp: August 02, 2013, 04:53:25 pm
content: Quote from: mikeselectricstuff on August 02, 2013, 04:46:36 pmYeah, it's been in the kernel for a long time now, at least on x86.

author: casper.bang
author_rank: Frequent Contributor
timestamp: August 02, 2013, 05:04:10 pm
content: Quote from: mikeselectricstuff on August 02, 2013, 04:46:36 pmSure, but not included in the kernel shipped with the mk802 Android sticks. Since the source code for these are propriatary, good luck compiling modules with a compatible symtable.Ok so no rs485, what about the rest?

author: 8086
author_rank: Super Contributor
timestamp: August 02, 2013, 05:17:52 pm
content: There's the IGEPv2http://igep.es/products/processor-boards/igepv2-boardI have one, it's nice. But it's 188 Euros.

author: Monkeh
author_rank: Super Contributor
timestamp: August 02, 2013, 06:35:03 pm
content: Quote from: casper.bang on August 02, 2013, 05:04:10 pmThe source code for the kernel cannot be. Tell them to live up to their end of the bargain.

author: Paul Moir
author_rank: Frequent Contributor
timestamp: August 02, 2013, 07:18:05 pm
content: NanosG20 + wifi usb stick? Probably not?

author: casper.bang
author_rank: Frequent Contributor
timestamp: August 02, 2013, 09:14:34 pm
content: QuoteEhh yeah, you know, noname Chinese compagnies have little regard for licencing stuff!

author: bingo600
author_rank: Super Contributor
timestamp: August 06, 2013, 02:39:11 pm
content: If you do the RS485 support your self ...3 suggestions ....1:Carambola2 (includes wifi)http://8devices.com/wiki_carambola/doku.php/http://shop.8devices.com/http://shop.8devices.com/wifi4things/carambola22:Beagleboard Blackhttp://beagleboard.org/Products/BeagleBone%20Black3:RasPI ....As 1 has the Wifi on it might be the nicest , but afaik it runs OpenWRT meaning , not a full Linux distro/Bingo

author: lgbeno
author_rank: Frequent Contributor
timestamp: August 06, 2013, 02:46:15 pm
content: Quote from: bingo600 on August 06, 2013, 02:39:11 pmI second the beagle bone black. You can use an inexpensive wifi USB dongle and then make a custom cape to convert the on chip UART to RS485 for just a few additional bucks.Using the native uart on the beagle bone black means that you won't need to deal with any USB to serial drivers as well.Sent from my iPhone using Tapatalk 2

author: lgbeno
author_rank: Frequent Contributor
timestamp: August 06, 2013, 02:47:33 pm
content: LogicPD or Gumstix is another option, don't think you'll beat the BBB price point with small volumes though.Sent from my iPhone using Tapatalk 2

author: Monkeh
author_rank: Super Contributor
timestamp: August 06, 2013, 02:48:14 pm
content: Quote from: casper.bang on August 02, 2013, 09:14:34 pmSo just sit there and let them get away with it. That'll help.

author: Marco
author_rank: Super Contributor
timestamp: August 06, 2013, 03:35:46 pm
content: Olimex has a RS485 cable (which converts RS232 to RS485) for their boards with UEXT connectors, which are all pretty cheap ... and they are serious about open source.

author: firewalker
author_rank: Super Contributor
timestamp: August 06, 2013, 04:00:16 pm
content: Quote from: casper.bang on August 02, 2013, 05:04:10 pmAre you referring to the following product?https://www.miniand.com/products/MK802%20Android%20Mini%20PCI think that there are a developer section to their forum with instructions for Lubuntu, ArchLinux etc. I believe that you could ask for help there.Also I am under the impression that there is an official driver for Android from FTDI. It may include RS485.http://www.ftdichip.com/Android.htmAlexander.

author: crisr
author_rank: Contributor
timestamp: August 10, 2013, 10:11:06 pm
content: I think US$35 for the RaspberryPi is hard to beat... all you need is a power supply, sd card and wifi dongle (a couple of bucks, or free if you already have them); for the RS-485, use a SN75176 ic (a few cents) -- and this is an EE forum after all -- on the Pi's UART, with maybe a level-converter (Pi is 3.3V logic non-5V-tolerant) and no need to mess with USB drivers.

author: DavidMenting
author_rank: Contributor
timestamp: August 22, 2013, 01:20:06 pm
content: Quote from: bingo600 on August 06, 2013, 02:39:11 pmI second this suggestion. Getting the FTDI driver running on the Carambola isn't too hard. The sources are there and the build system works nicely. I love this board for anything that needs to be small & cheap but still have Wi-Fi.

author: casper.bang
author_rank: Frequent Contributor
timestamp: August 22, 2013, 04:46:04 pm
content: Thanks guys. Carambola looks very interesting indeed!

author: tld
author_rank: Regular Contributor
timestamp: August 23, 2013, 08:52:07 pm
content: Just picked up two Carambol 2s from the postoffice today (one on dev board). OP saks arm though, and IIRC the Carambolas are MIPS.Not only do they bring WiFi, but also multiple Ethernet, host and device USB...(planning to give FreeBSD a spin on them btw)