SparkFun Forums

[tallganglyguy]

I've been playing with the EB-85A and a bluetooth radio module for the last little bit. But I'm having some problems getting up and going. I'm running both modules off a shared ~3.3V power supply. I am getting NMEA packets from the EB-85A over the bluetooth serial link. However, these packets don't contain any valid data.

When I enable the MCHN packet to get stats on the channels I can see that it is getting a weak signal (SNR of 3db) on several channels. Outside the SNR will go to about 20-30 but will never track the satellite for more than a couple of seconds.

I'm currently connecting Vcc, Gnd, TX1 and RX1. I have left TX2, RX2, and Vbat floating. The only thing that I can think might be causing a problem is the floating Vbat.

Does anybody have any thoughts on why my module might not be tracking satellites? Thanks in advance.
-Jerry.

[jandirks]

I can't help you really, but I want to mention this story.

I am part of a beta program for an autopilot for r/c planes. Initially I received an ETek EB-85A with the autopilot, but I and a few others never got any valid data with that GPS receiver. Actually, we received data, but it could never lock to any satellite.

About 2 weeks ago I received a different model GPS receiver (LS20033). That one also didn't work for me. Someone else who received the same GPS receiver earlier had it working, but suddenly it stopped working. He went back to his EB-85A (that had worked previously, but stopped working with same symptoms I experienced) to found out that it didn't need much time to get a lock to a couple of satellites.

The developer of the autopilot suggested me to try the EB-85A too. I was very surprised to see it worked.

We don't have a clue what is going on. Maybe the owner of the satellites is f*****g (fooling, that is) with us?

Good luck. If you find anything, please mention it here!

Regards,

JD

[NukWaste]

I have also had my trials and tribulations with the EB-85A Chip. My solution ended up using the SparkFun prototype board. I suspect that the problem is in the power supply setup. I tried all sorts of things before I got the proto board. But in the end it works great.

[ohararp]

GPS will be sensitive to "aerial" wire wrap and the like do to the "antenna" effect these connections can make. Using a ground plane, a real pcb, and a well filtered power supply and you should have any problems.

[jandirks]

Yeah, I read somewhere that the smallest ripple on supply can cause the Etek EB-85A not to work correctly.

JD

[funnynypd]

So, how do you enjoy this GPS module these days?