ZOE-M8Q functionality on external board

GPS/GNSS Development Boards
1

Good morning.

I have used the ZOE-M8Q SparkFun board for GPS while interfacing with many different microcontrollers. I decided I wished to check out if I can implement this circuit on my own PCB, so I used the same components and copied the schematic into my board design. The schematic is an exact replica of the SparkFun board, but the board layout is slightly different, some resistors/capacitors in different places then on the SparkFun board. However, I kept the RF antenna connector/polygon the same as in the SparkFun board, as I know that RF signals and antennas can be sensitive.

Upon implementing the ZOE-M8Q and it’s support circuit onto my custom PCB, I ended up being successful in communicating with it from the MCU, but I could not successfully read accurate information that is transferred from the antenna’s signal. I would like some advice why this is not connecting with the antennas signal. Does the ZOE-M8Q chip need to be manufactured/calibrated before use so that is can accurately read the coordinates via antenna? If someone can help me assess this technical dilemma I would be very grateful.

Thanks

2

There’s no calibration or anything needed, once we assemble these here, they just work.

You may have an impedance issue in your antenna circuitry, those were designed here with a specific board thickness in mind and to account for any surrounding circuitry.

could not successfully read accurate information that is transferred from the antenna’s signal.

What do you mean by this?

3

Basically attaching an antenna to the U.FL connector does not prove to be doing any GPS tracking. The communication between the GPS ZOE module and the MCU is fine, but the antenna does not connect to a satellite to be able for the ZOE chip to gather information. I am going to assume that this is a PCB interference issue with the antenna connector on the PCB.

4

What are you using as an antenna?

What data is the GPS sending back? (can you attach a sample?)

Are you outside when you are trying to use the GPS or inside a building?