Unable to get any data from UM980

I’ve gone through two of these boards thinking the first one was defective, but I can’t get any data out of my UM980 breakout thingy.

This is the antenna I’m using: Amazon.com: MASWELL GPS Antenna Screw and 3M Adhesive Mount SMA Male GNSS Antenna GPS GLONASS BEIDOU GAILEO L1 Band 1561-1602MHz IP67 Waterproof UV stabilized Nylon overbraids Cable : Electronics

Once connected to USB the board shows one solid red light, one solid blue light, and one blinking amber light. On the computer, lsusb shows:

# lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 008: ID 1a86:7523 QinHeng Electronics CH340 serial converter
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Connecting to the port via Minicom simply shows the state as “Offline.” No data comes through. I try to use ntripserver to collect data, but get nothing.

# ./ntripserver -M 1 -i /dev/ttyUSB0 -b 115200 -O 1 -a servers.onocoy.com -p 2101 -m MOUNTPOINTNAME -n CREDENTIAL -c NTRIPPASSWORD
serial input: device = /dev/ttyUSB0, speed = 115200
Destination caster, server or proxy host <servers.onocoy.com>
caster|server output: host = 35.207.172.57, port = 2101, mountpoint = unified-redbird-13241, mode = http

transfering data ...
ERROR: more than 120 seconds no activity
WARNING: reading input failed: Interrupted system call

For the life of me I don’t understand why I can’t get this thing to actually function.

I’d start by getting the correct antenna for this board. The GPS is a tri band GPS and your antenna is a single band antenna.

Try a 3 band (L1,L2,L5) antenna and see if that helps.

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Thanks for the heads-up but that wasn’t the problem. Bought the correct antenna and I’m having the exact same problems.

SparkFun? Help?

Hi @ccurzio ,

I’m sorry, the SparkPNT team is a bit thin on the ground at the moment…

And I don’t have a UM980 Breakout which I can test…

It could be your CH340 driver, but I’m really not sure. Are you able to connect to either of the other two UARTS? Do you perhaps have a 3.3V FTDI (UART-USB) cable you can use - one you’ve used before and which you know works with your Linux system?

It’s unlikely, but it could be an antenna voltage issue. If you have a digital multimeter, please measure the voltage between the SMA center pin and GND. It should be around 3VDC, with or without the antenna connected. If that voltage is missing, the antenna amplifier can’t function and you get ~zero signal. (I don’t actually know what happens if the UM980 has no signal. Most GNSS output ‘empty’ but valid NMEA sentences. I don’t know if the UM980 is the same.)

I hope this helps - in some small way,
Paul

If you’re not getting 3.3 volts at the antenna connector, please post a clear, high resolution photo of your board. That will help diagnose the issue.

Why suggest diagnosing antenna issues if there’s no confirmation that the original poster can even “talk” to the device over the serial interface (e.g., by sending version or config command)?

Every time you connect a serial interface device, you first confirm that the serial2usb device is recognized (it is, in this case), then you confirm you can send commands and receive responses (not done yet!), baud rate is set correctly, etc.

And only then you try hooking the device up to some sort of complex services (rtk2go, etc.)

Logical troubleshooting is dead as a skill.

@Bushman_K

The Unicore UPrecise evaluation software is only available for Windows. No use to the OP.

Your suggestion to check the CONFIG is a good one. The full command set is defined in the Commands Reference. Sending CONFIG\r\n at 115200 baud should return the three port and the PPS configurations.

The 4-pin JST connector provides direct access to COM2; COM3 can be accessed via the breakout pads. Both avoid the CH340 and any associated driver issues. Driver issues are more common than you might think.

Failure of the small inductor which provides power to the active antenna, is also more common than you might think. There are GNSS modules which go silent when there is no antenna signal. I honestly don’t know if the UM980 falls into that category. Checking the antenna voltage can be a very useful step.

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This makes no sense.
You don’t need UPrecise to talk to a serial port (and I didn’t mention it), any terminal software can do that, and it’s definitely available on Linux.

The question remains, is it actually set to 115200 (per your assumption) or not.

UM980 only “goes silent” when the antenna short is detected.

Perhaps you might have some suggestions for OP?

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How about this one?

Voltage on the antenna connector is correct. The UART driver is definitely okay as I’ve been able to communicate with the card(s) previously.

At this point I’m fed up. A $350 card and I can’t even get proper support from SparkFun other than other community users throwing out ideas of different things to try. While I definitely appreciate the help from contributing users, the community throwing things at the wall to see if anything sticks is NOT the level of manufacturer support I was expecting.

I’m returning the device. This is ridiculous.

This will be the last new SparkFun device that ever enters my home. Unbelievable.

In case you didn’t know, PaulZC is a sparkfun engineer so you are getting help from sparkfun. Just be patient, and know your problem is being worked on. The rest of us are users and volunteers. I don’t have your particular product so I don’t have experience with the hardware you have but i do have experience with many other GPS products.

Bushman_K has a good suggestion. Can you see anything coming from the GPS when you connect it to a PC and open the GPSs com port in a terminal emulator program like CoolTerm or RealTerm?

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Sorry about your frustration - if you’re done waiting we can certainly get it returned.

Was it purchased from us? If so head over to Returns - SparkFun Electronics (contact vendor if purchased elsewhere) and we’ll get ya squared away