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pps-gpio support in Friendlyarm 4.4

Posted: Mon May 07, 2018 10:19 am
by seanmnaes
Has anyone had any luck pps-gpio work in friendlyarm 4.x yet? I'm trying to use a Fire 3 I've got my gps talking to gpsd and ntpd, but I can't figure out how to get PPS into the mix.

-Sean

Re: pps-gpio support in Friendlyarm 4.4

Posted: Tue May 08, 2018 7:59 pm
by seanmnaes
I tried a different route using rpi_gpio_ntp but it couldn't detect any of the gpio pins I tried. Then I found a post here about using the Nanopi M3 without gpio drivers, but when I try:

Code: Select all

echo 92 > /sys/class/gpio/export

I don't end up with any gpio in /dev/.

Just trying to get pps working by any means. Kernel pps would be best but I'll take what I can get. Am I missing something?

Re: pps-gpio support in Friendlyarm 4.4

Posted: Sun Jun 10, 2018 6:38 pm
by bwilcutt
I have had no problem getting rpi to work on my Nano PI Neo via a GPIO. I selected GPIO 2, which is available. Is 92 available? Also, with RPI, you don't need to "export" the GPIO, just tell rpi which GPIO to use and it does the work for you:

From my /etc/rc.local:

/usr/local/bin/rpi_gpio_ntp -N 1 -g 2

Here I am specifying GPIO 2.

You can also test by doing the following:

root@Wilcutt:~# rpi_gpio_ntp -N 1 -g 2 -d
rpi_gpio_ntp v1.5, (C) 2013-2015 by folkert@vanheusden.com

NTP unit : 1
GPIO pin : 2
GPIO pout: -1
Fudge : 0.000000000
"Fork into the background" disabled because of debug mode.
1528637369.482893215] interrupt #1, 0 wraps, offset 0.482893s nan/0.482893/nan
1528637370.482790391] interrupt #2, 0 wraps, offset 0.482790s 0.482790/0.482842/nan
1528637371.482779647] interrupt #3, 0 wraps, offset 0.482780s 0.482785/0.482821/nan
(etc)

Again, my GPIO is #2.

I'm going to guess your GPIO pin is not a good one to choose.

Bryan

Re: pps-gpio support in Friendlyarm 4.4

Posted: Wed Dec 30, 2020 12:16 am
by CedricCox
seanmnaes wrote:
I tried a different route using rpi_gpio_ntp but it couldn't detect any of the gpio pins I tried. Then I found a post here go url about using the Nanopi M3 without gpio drivers, but when I try:

Code: Select all

echo 92 > /sys/class/gpio/export

I don't end up with any gpio in /dev/.

Just trying to get pps working by any means. Kernel pps would be best but I'll take what I can get. Am I missing something?




Wow, it is definitely useful for my project, thanks!