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Re: [gpsd-dev] Modifying (severly) hardware.html
From: |
Gary E. Miller |
Subject: |
Re: [gpsd-dev] Modifying (severly) hardware.html |
Date: |
Wed, 15 Apr 2015 13:21:02 -0700 |
Yo Hal!
On Wed, 15 Apr 2015 13:09:33 -0700
Hal Murray <address@hidden> wrote:
>
> > 1. Does the serial-to-USB chip pass PPS events handed to the serial
> > side out the USB side as interrrupt packets? The PL2303 does. FTDI
> > chips do not.
>
> Are you sure about the FTDI chip not working? Is that all of the
> FTDI chips or just some/most of them?
USB 1.1 has no concept of 'interrupts", everything is polled.
As for FTDI, I have several USB 2.0 here passing PPS just fine. I
get under 100 µSec jitter with them.
[ 4.158684] usb 5-1: New USB device found, idVendor=0403, idProduct=6001
[ 4.161234] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 4.163714] usb 5-1: Product: FT232R USB UART
[ 4.166157] usb 5-1: Manufacturer: FTDI
[ 4.168574] usb 5-1: SerialNumber: A4YMZFYQ
[ 4.175697] ftdi_sio 5-1:1.0: FTDI USB Serial Device converter detected
[ 4.177792] usb 5-1: Detected FT232RL
[ 4.183157] usb 5-1: FTDI USB Serial Device converter now attached to ttyUSB1
> Is there a simple test case for TIOCMIWAIT? Can I tell gpsd/gpsmon
> to not use RFC2783?
You need to special build a debug binary. Maybe rename timepps.h first
to kill the RFC2783.
RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97701
address@hidden Tel:+1(541)382-8588
Re: [gpsd-dev] Modifying (severly) hardware.html, Gary E. Miller, 2015/04/13