SparkFun GPS Breakout (ZOE-M8Q and SAM-M8Q) Hookup Guide

Contributors: Elias The Sparkiest

SparkFun SAM-M8Q Hardware Overview

Power

Power for this board is 3.3V. There is a 3.3V pin on the PTH header along the side of the board, but you can also provide power through the Qwiic connector.

Battery

The small metal disk in the upper left corner is a small lithium battery. This battery does not provide power to the IC like the 3.3V system does, but to relevant systems inside the IC that allow for a quick reconnection to satellites. The time to first fix will about ~29 seconds, but after it has a lock, that battery will allow for a one second time to first fix. This is known as a hot start and lasts for four hours after the board is powered down. The battery provides over a years worth of power to the backup system and charges slowly when the board is powered.

LEDs

There's a single red power LED just above the Qwiic connector to indicate that the board is powered. There is another LED labeled PPS that is connected to the Pulse Per Second line on the GPS chip. When connected to a satellite, this line generates a pulse that is synchronized with a GPS or UTC time grid. By default, you'll see one pulse a second.

Jumpers

There are three jumpers on the topside of the product, each labeled with its function. At the bottom right of the picture is a three way jumper labeled I²C that connects two pull-up resistors to the I²C data lines. If you have many devices on your I²C data lines, then you may consider cutting these. Just above that jumper is the JP2 jumper. If you cut this trace it will disconnect the Power LED just above the Qwiic connector. Finally, on the left side of the product is the JP1 jumper that when cut disconnects the PPS LED.

Chip Antenna

This GPS unit at the center of the PCB may look a bit funky to you. In fact you may be thinking, "Wow, that looks suspiciously like a GNSS Antenna....". That's very astute dear hookup guide peruser. This GPS IC is actually built into the antenna giving you an all-in-one GPS solution.

FTDI Header

At the top of the board, we have the traditional pinout for an FTDI header. Make sure that the FTDI that you use is 3.3V and not 5V!

Qwiic and I²C

At the opposite side of the board. There are two pins labeled SDA and SCL which indicates the I²C data lines. Similarly, you can use either of the Qwiic connectors to provide power and utilize I²C. The Qwiic ecosystem is made for fast prototyping by removing the need for soldering. All you need to do is plug a Qwiic cable into the Qwiic connector and voila!

Broken Out Pins

There are four other pins broken out: Pulse per second PPS, Reset RST, Safeboot SAFE, and finally the interrupt pin INT. The first pin PPS outputs pulse trains synchronized with the GPS or UTC time grid. The signal defaults to once per second but is configurable over a wide range. Read the u-blox Receiver Protocol Specification in the Resources tab for more information. The reset pin resets the chip. The next pin, SAFE is used to start up the IC in safe boot mode. The final pin INT can be used to wake the chip from power save mode.

GPS Capabilities

The SAM-M8 is able to connect to up to three different GNSS constellations at a time making it very accurate for its size. Below are the listed capabilities of the GPS unit.

Board Dimensions

The board is 1.6"x1.6", which is slightly bigger than a typical Qwiic board. The board includes four mounting holes on each corner of the board.