Advanced users • PPS not working on Bullseye

Just put together a new Pi, 4B - Raspberry Pi 4 Model B Rev 1.5 running Raspbian Bullseye 11.10. It has Adafruit Ultimate GPS hat on it, with MKT3333 Globaltop chip. I have the same hat on a 2b+ that works fine. I'm getting an error loading ntpd 4.2.8p15:

Aug 20 10:02:36 ntp3 ntpd[792]: refclock_ppsapi: time_pps_create: Operation not supported
Aug 20 10:02:36 ntp3 ntpd[792]: GPS_NMEA(0) flag1 1 but PPSAPI fails

I have /dev/pps0 with correct perms

root@ntp3:/etc# ls -la /dev/pps0 /dev/gps0 /dev/serial0 /dev/ttyAMA0
lrwxrwxrwx 1 root root 7 Aug 20 09:48 /dev/gps0 -> ttyAMA0
crw-rw---- 1 ntp ntp 250, 0 Aug 20 09:35 /dev/pps0
lrwxrwxrwx 1 root root 7 Aug 20 09:35 /dev/serial0 -> ttyAMA0
crw-rw---- 1 root dialout 204, 64 Aug 20 09:35 /dev/ttyAMA0

ppsctl yields this error:

root@ntp3:/var/log# ppsctl -a -b /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
Bind failed: Operation not supported

pps_gpio module appears loaded but not in use:

root@ntp3:/var/log# lsmod | grep pps
pps_gpio 16384 0

I don't see pps_core however I read somewhere that is now builtin ? not a kernel module .ko anymore?

My config.txt looks like so:

# disable Bluetooth and WiFi
#dtoverlay=miniuart-bt
dtoverlay=disable-bt
dtoverlay=disable-wifi

[all]
# Adafruit GPS Hat GlobalTop MTK3333 PPS on gpio pin #4
dtoverlay=pps-gpio,gpiopin=4
init_uart_baud=9600
enable_uart=1

and ntp.conf like so:

# GlobalTop MTK3333 NMEA with PPS enabled
# MTK3333 does not (newer model)
server 127.127.20.0 mode 17 minpoll 4 iburst true prefer
# fudge flag1 1 enables PPSAPI,
# fudge flag3 1 enables kernel clock discipline
fudge 127.127.20.0 flag1 1 flag3 1 # MKT3333
fudge 127.127.20.0 refid GPS

ntpd is working but no PPS.

root@ntp3:/etc# ntpq -c peers
remote refid st t when poll reach delay offset jitter
==============================================================================
*GPS_NMEA(0) .GPS. 0 l 13 16 377 0.000 -9.970 11.885
+ntp1.local.lan .GPS. 1 u 8 16 377 0.373 +525.31 2.304
+ntp2.local.lan .GPS. 1 u 7 16 377 0.249 +524.81 2.635
-159.203.82.102 173.71.78.103 2 u 65 64 377 118.058 +527.25 14.464
-four10.gac.edu 169.117.81.12 2 u 4 64 377 110.446 +522.94 13.866
-23.150.40.242 204.9.54.119 2 u 57 64 377 108.349 +545.15 15.512
-s2-b.time.mci1. 42.20.202.230 2 u 67 64 377 108.807 +523.80 19.046

NMEA output is working:

root@ntp3:/etc# cat /dev/gps0
$GNVTG,0.00,T,,M,0.00,N,0.01,K,D*27
$GNGGA,203826.000,2116.9173,N,15748.3612,W,2,12,0.83,49.3,M,4.6,M,,*6B
$GPGSA,A,3,27,08,32,21,31,02,03,04,28,,,,1.79,0.83,1.58*08
$GLGSA,A,3,71,86,85,,,,,,,,,,1.79,0.83,1.58*13
$GNRMC,203826.000,A,2116.9173,N,15748.3612,W,0.01,0.00,200824,,,D*66
$GNVTG,0.00,T,,M,0.01,N,0.01,K,D*26
$GNGGA,203827.000,2116.9173,N,15748.3611,W,2,12,0.83,49.3,M,4.6,M,,*69
$GPGSA,A,3,27,08,32,21,31,02,03,04,28,,,,1.79,0.83,1.58*08
$GLGSA,A,3,71,86,85,,,,,,,,,,1.79,0.83,1.58*13
$GNRMC,203827.000,A,2116.9173,N,15748.3611,W,0.01,0.00,200824,,,D*64
$GNVTG,0.00,T,,M,0.01,N,0.01,K,D*26

Lastly, ppstest shows that pps works:

root@ntp3:/etc# ppstest /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
ok, found 1 source(s), now start fetching data...
source 0 - assert 1724186567.469540327, sequence: 4053 - clear 0.000000000, sequence: 0
source 0 - assert 1724186568.469454461, sequence: 4054 - clear 0.000000000, sequence: 0
source 0 - assert 1724186569.469374752, sequence: 4055 - clear 0.000000000, sequence: 0
source 0 - assert 1724186570.469294635, sequence: 4056 - clear 0.000000000, sequence: 0
source 0 - assert 1724186571.469219482, sequence: 4057 - clear 0.000000000, sequence: 0
^C

I'm not sure whats wrong and would appreciate some guidance please :^D

I'm gonna try building ntpd from source next.

Statistics: Posted by starquad — Tue Aug 20, 2024 8:47 pm

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