This GMM GPS module features a GlobalTop Gmm-u1 GPS receiver combined with a MMA8652 3-axis accelerometer in a Raspberry Pi friendly pHAT format. No Raspberry Pi is included.

Pin Out

The pin out of the Gmm-u1 GPS module on the Raspberry Pi GPIO connector is as shown. The module is powered from the 5V pins 2 & 4 of the Raspberry Pi. A red LED indicates power is connected. All the ground pins on the GPIO header are connected. An onboard regulator provides the 3.3V required by the module. Inputs are not 5V tolerant. The Gmm-u1 GPS receiver connects via the serial port on pins 8 & 10. A yellow LED indicates the state of the GPS fix. It is off when the GPS receiver does not have a fix and it blinks when a fix has been obtained. The MMA8652 accelerometer connects via I2C on pins 3 & 5. Its interrupt outputs can optionally be connected to pins 13 & 15 either via wire links or jumpers (not provided). Pins 29 & 31 are brought out of the GPIO header so each can be used for a control button input. Pin 37 is connected to a green LED that can be used as a status signal.

No Clutter

The Raspberry Pi friendly pHat format of this module allows it to replace the clutter of several break out boards with a single application ready module. The module is compatible with all Raspberry Pi boards with the standard 40 pin GPIO connector.

Two normally open buttons can be connected between GPIO pins 29 or 31 and ground to provide a program running on the Raspberry Pi with control button inputs.

The MMA8652 3-axis accelerometer has two user programmable interrupt outputs which can be optionally connected to pins 13 & 15 on the Raspberry Pi GPIO header. Each of the MMA8652 interrupt pins can be individually set to one of seven different data ready / motion / orientation conditions. The MMA8652FC accelerometer data can be converted into an estimation of pitch and roll angles.

40 way header

The module is supplied with a 40 way female header. By default this will be supplied unsoldered, but can be supplied soldered to the module on request.

Specification

GlobalTop Gmm-u1 GPS receiver

MMA8652 3-axis accelerometer

Weight 8g

Dimensions 65 x 30 x 4mm LxWxH

Power supply required 5V DC from Raspberry Pi*

Power consumption 90mA with antenna

Operating Temp. 0° - 85°C

*This module is designed to powered from a Raspberry Pi so there is no reverse polarity protection.

Gmm-u1 GPS Receiver

The Gmm-u1 is a GPS Module based on the MTK MT3329 chipset. It provides a solution with highly accurate position and speed performance as well as high sensitivity and tracking capabilities in urban conditions. An external antenna is required which can be connected to the u.FL connector on the board. A small ceramic chip antenna is provided. A larger external antenna can be connected either via a u.FL pigtail or by installing an optional MMA or SMA connector onto the board.

Chipset MTK MT3329

Channels 66 channels

Altitude Maximum 18,000m (60,000 feet)

Velocity Maximum 515m/s (1000 knots)

Update Rate 5Hz (default), maximum 10Hz

Baud Rate 38400 bps (default) 4800 - 115200bps

Output protocol NMEA 0183

Input protocol PMTK

Working Temperature -40 °C to +85 °C

MMA8652FC, 3-Axis, 12-bit, Digital Accelerometer

The MMA8652FC is a low-power, three-axis, accelerometer with 12 bits of resolution. This accelerometer is packed with flexible, user-programmable, embedded functions with options configurable to two interrupt pins. The device can be configured to generate interrupt signals so data does not need to be continuously polled data to monitor inertial events.

±2 g, ±4 g, and ±8 g dynamically selectable full-scale ranges

12-bit digital output

1mg per LSB High Sensitivity with low noise

Output Data Rates (ODR) from 1.56 Hz to 800 Hz

32-sample FIFO

I2C digital output interface with 2 programmable interrupt pins & 7 interrupt sources

Configurable motion detection (Freefall, Motion, Pulse, Transient)

Orientation (Portrait/Landscape) detection with programmable hysteresis