--- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
On Sun, Jul 17, 2016 at 12:30 PM, Nick Hardiman nick@internetmachines.co.uk wrote:
So if I got this right, I can set up a card with network access in three ways - a minimal standalone setup, a full desktop setup, or a PCB for many cards. First two are linked to the current crowdsourcing campaign, third one is a future enhancement.
correct.
Here’s what I understand about the first two. This look right? Please excuse my rough ASCII connections diagrams
we like ascii connections. thank you for not doing them as HTML.
a minimal standalone setup
power socket | power plug, $6 delivering at least 3 watts, so thats practically any USB charger https://www.amazon.com/AmazonBasics-Wall-Charger-Outlet-Output/dp/B005CG2ATQ... | USB OTG cable, $1.63 (!) https://www.amazon.com/Micro-Cable-Power-Samsung-Player/dp/B00CXAC1ZW/ or USB + HDMI Cable Set, $15 https://www.crowdsupply.com/eoma68/micro-desktop | | | USB to Ethernet adapter | This one seems to contain an ASIX chip (AX88178) | $25 | http://plugable.com/products/usb2-e1000
plugable... mmmm... you're better off buying from thinkpenguin.
| | | Network cable, to the network, say $10 | Libre Tea Computer Card, $65
that's basically it. you won't be able to see any of the boot logs, early kernel messages or OS boot logs with this setup.
if you were to get the cable set *and* then plug in the HDMI cable *and* the bootloader and kernel were configured to display onto HDMI, *then* you would be able to use just the above, because you could plug in a keyboard instead of the USB-ETH adapter.
a full desktop setup, for seeing boot loader and kernel messages
boot loader and kernel messages go to where the boot loader and kernel are configured to send them. *early* messages can *only* go to the serial port. this isn't a PC, it's an embedded computer. if you're not familiar with this you should read up on it, on the linux-sunxi wiki, and ask more questions when you need to.
basically the boot proces goes:
* BROM (boot rom) http://linux-sunxi.org/BROM * NAND or SD/MMC 16k "very early bootloader". this is so small it can only do serial debug output
depending on the very early bootloader, some people use allwinner boot0/boot1, other people use u-boot "SPL" early bootloader, you have different choices.
* after u-boot-spl you can go direct to u-boot and from there LCD or HDMI or UART is initialised, you can get early u-boot messages on LCD or UART * boot0/boot1 is a bit weird, it can do LCD / HDMI initialisation but it's for tablets, you don't get log messages. you can put in your own u-boot, that's where you could get LCD/HDMI started
from there you get to kernel, that's when you have "console=XXXX" from u-boot and associated scripts (uEnv.txt), that says where the kernel console output goes.
i will have this all set up correctly so that you won't need to do it or know all of it in advance, and there will be people (at least me) who can guide you through modifying it for particular setups. there's also the linux-sunxi community.
Libre Tea Computer Card $65 https://www.crowdsupply.com/eoma68/micro-desktop | Micro Desktop Housing $55 https://www.crowdsupply.com/eoma68/micro-desktop | | | | | Network cable, to the network, say $10 | | | Keyboard, Video, Mouse, say $100 | power plug (a USB charger?)
no, a 7-21v PSU (i'll likely supply a 12v one) with a standard 5.5mm pin-positive jack. the PSU is part of the micro-desktop kit.
l.