USB/serial converters, and upcoming dumb questions

in prep for a presentation i want to give later this year on the
beagleboard, i'm going to have a number of upcoming (possibly
seriously dumb) questions, just so i know i can answer them if someone
asks *me*. so be patient, please.

  first, does anyone have a USB/serial converter working to talk their
BB? as most folks know, new systems typically don't have serial
ports, so you typically need to use a USB solution to connect to the
BB console.

  at the moment, i have:

  USB port ->
    targus port replicator ->
      outgoing serial port with null modem cable ->
        everex AT cable ->
          BB console port

and that works fine, with minicom humming right along on my fedora 11
(preview system).

  to cut down the tangle, i tried to replace the targus port
replicator with a no-name USB/serial converter going straight from the
host USB port to the null modem cable. when i plug it in, hotplug
loads the "pl2303" kernel module, but i have yet to get this to work
-- what i get via minicom is unprintable junk spewed out, as if the
baud rate is wrong or something.

  targus port replicator: totally reliable. USB/serial converter:
hasn't worked yet. this may well be a fedora issue, so i'm interested
if anyone has one of these working under a different host distro, so i
can file a bug report against fedora about it. thanks.

rday

targus port replicator: totally reliable. USB/serial converter:
hasn't worked yet. this may well be a fedora issue, so i'm interested
if anyone has one of these working under a different host distro, so i
can file a bug report against fedora about it. thanks.

I use no name usb to serial adapters with Fedora without any trouble.
I am using kermit though.

Philip

* you still need the null modem cable, right?
  * do you know which kernel module is loaded to support that
    converter when you plug it in?

rday

> targus port replicator: totally reliable. USB/serial converter:
> hasn't worked yet. this may well be a fedora issue, so i'm
> interested if anyone has one of these working under a different
> host distro, so i can file a bug report against fedora about it.
> thanks.

I use no name usb to serial adapters with Fedora without any
trouble. I am using kermit though.

* you still need the null modem cable, right?

Yes.

* do you know which kernel module is loaded to support that
   converter when you plug it in?

Er, never looked ...

nothing in lsmod is jumping out at me. I'll check closer next time I
can easily unlplug the adapter.

Philip

for me, it was "pl2303", the Prolific serial adapter driver. i was
just curious if your insertion loaded something else, which might help
me debug what's happening.

rday

Bus 002 Device 003: ID 9710:7720 MosChip Semiconductor
Bus 002 Device 002: ID 9710:7720 MosChip Semiconductor

Is what I see. I have two double serial units for four serial ports.

Philip

>> Er, never looked ...
>>
>> nothing in lsmod is jumping out at me. I'll check closer next time I
>> can easily unlplug the adapter.
>
> for me, it was "pl2303", the Prolific serial adapter driver. i was
> just curious if your insertion loaded something else, which might
help
> me debug what's happening.

Bus 002 Device 003: ID 9710:7720 MosChip Semiconductor
Bus 002 Device 002: ID 9710:7720 MosChip Semiconductor

Is what I see. I have two double serial units for four serial ports.

I know of 3 major USB2UART converter chip-manufacturers, although others
exist as well:
1) FTDI-chip
2) MosChip
3) Prolific

In general I have never had any trouble using FTDI. MosChip has troubled me
a single time, and Prolific several, although I can't really tell what's the
main difference between the different chips. I think most of the problems
(if not all) are SW-related, but I would definitely aim at a FTDI solution
in case I can choose myself :slight_smile:

That was my 5 cent
  Søren

Er, never looked ...

nothing in lsmod is jumping out at me. I'll check closer next time I
can easily unlplug the adapter.

for me, it was "pl2303", the Prolific serial adapter driver. i was
just curious if your insertion loaded something else, which might

help

me debug what's happening.

Bus 002 Device 003: ID 9710:7720 MosChip Semiconductor
Bus 002 Device 002: ID 9710:7720 MosChip Semiconductor

Is what I see. I have two double serial units for four serial ports.

I know of 3 major USB2UART converter chip-manufacturers, although others
exist as well:
1) FTDI-chip
2) MosChip
3) Prolific

In general I have never had any trouble using FTDI. MosChip has troubled me
a single time, and Prolific several, although I can't really tell what's the
main difference between the different chips. I think most of the problems
(if not all) are SW-related, but I would definitely aim at a FTDI solution
in case I can choose myself :slight_smile:

That was my 5 cent
Søren

FTDI is very good. ( 10 out of zero to ten ) I have also had success with IOGear ( 8 out of zero to ten ).
Gus