HC1 UART design

Moderators: odroid, mdrjr

HC1 UART design

Unread postby rgmhtt » Fri Dec 07, 2018 8:46 am

The board connector is a challenge to use. It is like connect it and forget it. Cannot easily connect and unconnect. It would not be bad if I knew I could get a bag full of the jumper cables, but I have yet to find them. And the connector cable is too short to run out the back of a covered HC1 and there is no hole in the front or top of the cover for the cable. I am going have to use my Dremmel to make one.

Of course the cable connector to the TTL/USB adapter is hard to work with. Again, I would like to have each (future) HC1 with a cable on it and plug the (expensive) adapter into the unit when I need console access. I get the 1.8v vs 3.3v design; I you just like either affordable adapters or ease of moving adapters between boards.

Finally my Fedora 28 notebook does not always recognize it has a ttyUSB0 device. I have to unplug and plug in again, sometimes twice before it picks up the connection. It could be my notebook or F28. More likely it is that adapter, as I do not have this problem with the 3.3v adapters I use for my Cubieboard work.
rgmhtt
 
Posts: 17
Joined: Fri Dec 07, 2018 7:30 am
languages_spoken: english
ODROIDs: HC1

Re: HC1 UART design

Unread postby odroid » Fri Dec 07, 2018 10:06 am

We've been using the popular Molex 5268-04a connector since we launched the old ODROID-X in 2012.
https://wiki.odroid.com/accessory/development/usb_uart_kit
Even though the connector might not be common in some countries, it is not easy to change the mating connectors because we've already shipped several thousands of official USB-UART kit cables every year.

BTW, we may need to consider increasing the 4-wire cable length one day.
Current cable length is 100mm approximately. Can you tell me a suggested cable length?
User avatar
odroid
Site Admin
 
Posts: 29098
Joined: Fri Feb 22, 2013 11:14 pm
languages_spoken: English
ODROIDs: ODROID

Re: HC1 UART design

Unread postby rgmhtt » Fri Dec 07, 2018 10:28 am

If the cable was only 20mm longer, I could run it out the back over the sata drive instead of making new holes in your plastic cover. 40mm would probably be better.

Also if the cables were available in small lots (like 10), then they could be left connected in a stack of HC1s and plug the adapter into whichever unit needed the console at the time. Perhaps Digi-key might be a source....

I could always file down the connector a bit so it is easier to connect/unconnect without compromising the quality of the connection.

thanks
rgmhtt
 
Posts: 17
Joined: Fri Dec 07, 2018 7:30 am
languages_spoken: english
ODROIDs: HC1

Re: HC1 UART design

Unread postby rgmhtt » Fri Dec 07, 2018 10:32 am

Or modify the plastic cover for the HC1. There is space next to the LAN hole for the cable. With my Dremmel, I can cut a slit over to a hole drilled in that space and run your current 100mm cable through. If I could buy just the cables as needed.
rgmhtt
 
Posts: 17
Joined: Fri Dec 07, 2018 7:30 am
languages_spoken: english
ODROIDs: HC1

Re: HC1 UART design

Unread postby odroid » Fri Dec 07, 2018 10:53 am

We will consider changing the cable length to 150mm from 100mm and selling the 4-pin cable assembly separately as a spare part too.

Because most users don't use the UART console access frequently, we have no plan to change the plastic shield design.
User avatar
odroid
Site Admin
 
Posts: 29098
Joined: Fri Feb 22, 2013 11:14 pm
languages_spoken: English
ODROIDs: ODROID

Re: HC1 UART design

Unread postby phaseshifter » Mon Dec 10, 2018 10:10 am

i think selling the short 4 wire cable as a spare part is a good idea..

i use the uart kit prolly more than the average user would
and i have had to replace my kit several times over the span of 3 odd or so years now since i have been on the forum...
i find that the wires break off the connector cable..through frequent usage

i would much rather have just brought the 4 wire cable rather than replacing the whole kit/unit

i would also like to add that the 4 wire cable should come with some assembly instructions as care must be taken to replace it the correct way...
it can be accidentally be fitted in reverse order or backwards..
it is quite easily done and the user may think that he/she has a further problem that they have not realized the cable is connected backwards..


perhaps`s a reference to the "wiki" page regarding the uart kit could be a "how to replace the uart the short 4 wire connecting cable"....would be an easy way to go about things

and maybe a reference added to the advertising page ..as a how to ..etc..etc..
Build It And They Will Come...Be Bold And Mighty Forces Will Come To Your Aid..!!!
phaseshifter
 
Posts: 3000
Joined: Fri May 08, 2015 9:12 am
languages_spoken: english
ODROIDs: N-1..c1+ ..c-2..xu3 lite,xu4...u-3..
u-2...other odroid acc`s as well

Re: HC1 UART design

Unread postby rgmhtt » Tue Dec 11, 2018 4:11 am

I just conducted a little test.

I powered off my HC1 running Fedora29. I disconnected the serial USB adapter. I powered back up. I SSHed into the unit to determine it was up and running properly. I connected the adapter, connected it to my host notebook and started screen to ttyUSB0 and there was the console login.

The reason for this test?

Is it adequate to have the connector cables in place and only connect the serial USB adapter when you need console access, thus saving money if you have a stack of servers.

Answer is it seems to work, at least for one try.

Thus I am interested in being able to purchase JUST the connector cables, and at the 150mm length.

That once I work everything out for this first unit, THEN buy a second... :D

thank you.
rgmhtt
 
Posts: 17
Joined: Fri Dec 07, 2018 7:30 am
languages_spoken: english
ODROIDs: HC1


Return to Issues

Who is online

Users browsing this forum: No registered users and 1 guest