Comments on: Motorola Oncore UT+ and LinuxPPS

By: Billi

Billi — Sat, 10 Oct 2009 20:50:50 +0000

Ich denke das ist ein wenig zu hoch für mich - trotzdem danke für´s posten.

By: Panachoi

Panachoi — Mon, 20 Apr 2009 10:13:05 +0000

Whats the device labelled 390E on the schematic between the 5V line and the battery backup input?

By: udo

udo — Fri, 30 Jan 2009 15:08:39 +0000

Also: what is the best way to create a nice hole in the computer case (of my Epia board) for the BNC female plug that is at the end of my so called pigtail?
I want no metallic particles and a nice clean hole.
A classic drill or are there better methods?
Anyone?

By: udo

udo — Tue, 20 Jan 2009 18:38:56 +0000

Thanks. I can cut off a piece of an old connector.

Also: I can jumper 3 of the 4 serial ports on an Epia LT board for 5V instead of 12V.
Would that eliminate (some of ) the buffering/inversion electronics you mention?

By: Remco

Remco — Wed, 14 Jan 2009 19:56:19 +0000

Hello Udo,

I used a header connector from an old floppy drive cable. But, later on I soldered the wires on the pins.

Remco

By: udo

udo — Tue, 13 Jan 2009 15:21:47 +0000

Hi,

Where to get the connector for the gps-module’s serial I/O, power, etc in the Netherlands? (8 pins I believe)

Udo

By: Remco

Remco — Tue, 28 Oct 2008 06:55:43 +0000

Hello Adam,

To have a ‘level converter’ from TTL <> RS232 you also need to invert the signals. I used a 74HC14 (or a LS04, or whatever to invert and two resistors and a diode to ‘level’ the signal _from_ the computer. It is not necessary to ‘level’ the PPS-signal or to invert it. I did it for safety purposes, and accordingly had to set the CLEAR flag in /etc/ntp.oncore.0
See picture or shall I publish a diagram of the interface?

Remco

By: Hal V. Engel

Hal V. Engel — Fri, 19 Sep 2008 22:19:08 +0000

Adam,

I am using an OnCore UT+ with LinuxPPS. I used a cheap TTL to RS232 kit off ebay (<$10 shipped) to handle the TX and RX TTL/RS232 conversion and ran the PPS signal directly to the DCD pin of the serial port (IE. the serial port see a TTL signal). This works for me and many other Oncore users.

Hal

By: Adam Dosch

Adam Dosch — Tue, 16 Sep 2008 02:21:12 +0000

Remco,

Hey friend! I’m looking to do the *exact* same thing for an NTP project I am doing here in the US. I’ve found some Motorola OnCore UT+ units online and, like you, on eBay that I’d like to purchase.

I’ve been looking at the UT+ datasheet and it’s at least apparent I need to whip up a TTL to rs232 converter (going to use a MAX232 chip) but I was curious how you handled that. I know I need to TTL shift the TX and RX, but is it necessary to TTL shift the 1PPS or can I pull that straight off the receiver and go straight to DCD pin on DB9?

I’d like to chat with you offline if you care to pick your brain about this.

Thanks a lot and great site.

-Adam