Good afternoon,
I recently ran into an interesting experience here with a Raspberry Pi 4b (8GB), a V6.3 Uputronics GPS / RTC expansion board (https://store.uputronics.com/products/r ... sion-board), and Raspian Bookworm.
I wonder if it's a common issue or just my install at fault that USB3 and the Uputronics GPS / RTC expansion board are not compatible?
Specifically, I set up a Raspberry Pi4b with the expansion board per the datasheet mentioned at the Uputronics site. It responds as expected for NTP, etc. and the PPS green LED blinks happily every second, indicating a good fix. NTP works as expected, all is well, until I insert any kind of mass-storage device with a USB3 connector into one of the two USB3 receptacles on the Rpi4b. Once I do that, the PPS light stops blinking and the fix appears to die too as the device reverts to Stratum 2 (it mooches off some Centerclick NTP appliances instead).
Pull the USB3 device back out of the RPi4b and the PPS light comes back on almost instantly. Doesn't matter if it's a 2.5"HDD with a power splitter cable or a finger-nail sized flash drive, if I insert a USB3 mass storage device into the USB3 receptacle, the PPS / GPS / etc. die. I can insert a USB2 mass storage device into the USB3 port and all is well, I can insert a USB3 device into the USB2 receptacles, but USB3+USB3 is kills the GPS.
Here is my ask: can someone else try this out on their Rpi4b / Uputronics Expansion Board rig and tell me if they have the same response?
I recently ran into an interesting experience here with a Raspberry Pi 4b (8GB), a V6.3 Uputronics GPS / RTC expansion board (https://store.uputronics.com/products/r ... sion-board), and Raspian Bookworm.
I wonder if it's a common issue or just my install at fault that USB3 and the Uputronics GPS / RTC expansion board are not compatible?
Specifically, I set up a Raspberry Pi4b with the expansion board per the datasheet mentioned at the Uputronics site. It responds as expected for NTP, etc. and the PPS green LED blinks happily every second, indicating a good fix. NTP works as expected, all is well, until I insert any kind of mass-storage device with a USB3 connector into one of the two USB3 receptacles on the Rpi4b. Once I do that, the PPS light stops blinking and the fix appears to die too as the device reverts to Stratum 2 (it mooches off some Centerclick NTP appliances instead).
Pull the USB3 device back out of the RPi4b and the PPS light comes back on almost instantly. Doesn't matter if it's a 2.5"HDD with a power splitter cable or a finger-nail sized flash drive, if I insert a USB3 mass storage device into the USB3 receptacle, the PPS / GPS / etc. die. I can insert a USB2 mass storage device into the USB3 port and all is well, I can insert a USB3 device into the USB2 receptacles, but USB3+USB3 is kills the GPS.
Here is my ask: can someone else try this out on their Rpi4b / Uputronics Expansion Board rig and tell me if they have the same response?
Statistics: Posted by FabSpiderCrab — Sun Sep 07, 2025 7:39 pm