Compute Module • Configuring CM4 with HW-658 GPS Module

I have a CM4 on the Compute Module 4 IO Board, connected to a HW-658 GPS module as follows:
GPS VCC to CM4 GPIO pin 2
GPS GND to CM4 GPIO pin 6
GPS TXD to CM4 GPIO 15 (RXD)
GPS RXD to CM4 GPIO 14 (TXD)
GPS PPS to CM4 GPIO 18 (PCM_CLK)

GPS module LED is flashing once per second.

pps-tools is v 1.0.2-2+b1
produces each second:
Source 0 -assert <time>, sequence <index> -clear 0.00000, sequence 0
s displays the N-E-S-W map but populates no satellites
produces:
Creating/updating gpsd user account...
gpsd.service is a disabled or a status unit not running, not starting it

What am I doing wrong?

Statistics: Posted by davesedar — Fri Jan 02, 2026 2:54 pm — Replies 0 — Views 16

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