GPS Receiver hardware and sketch using Tiva TM4C LaunchPad, SparkFun ZOE-M8Q GPS breakout, and CrystalFonz 8x2 LCD. The sketch is based on Example12_UseUart.ino by Nathan Seidle from the SparkFun u-blox Arduino Library.
The ZOE-M8Q I2C interface is unreliable in my setup. I am not sure if this is a problem with the hardware or the SparkFun library. This sketch uses UART to communicate between the LaunchPad and the GPS module, without issue. The Tiva TM4C LaunchPad has 8 available hardware serial ports. This sketch uses UART module 1 (accessed using the "Serial1" object). Debug information is sent through the usual "Serial" USB backchannel.
The LCD display cycles between several GPS data values (lat/long, altitude, # satellites, ground speed, date/time). Hold down "SW1" on the LaunchPad to freeze the display at the current reading.
The GPS can LCD are connected to the LaunchPad as follows:
LaunchPad GPS LCD Signal Name
--------- --- --- ----------------
1 4 3V3
2
3 2 LP RX1 <- GPS TXO
4 3 LP TX1 -> GPS RXI
5
6
7
8
9 7 SCL (This sketch does not use I2C)
10 8 SDA (This sketch does not use I2C)
11 4 RS
12 6 E
13 11 DB4
14 12 DB5
15 13 DB6
16
17
18 14 DB7
19
20 6 1,5 GND (LCD pin 5 is R/W*)
21 2 +5V (VDD)
3 Vo (wiper pin on 10K pot tied between +5V and GND)
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SparkFun u-blox Arduino Library
This sketch uses SparkFun's u-blox Arduino library. That library has since been deprecated and replaced with SparkFun's u-blox GNSS library. Migrating to the new library requires some minor sketch updates as outlined here.
- SparkFun ZOE-M8Q GPS Breakout
- Texas Instruments TM4C LaunchPad
- Embedded Computing pinout diagram
- Note that RX1/TX1 on pins 37/36 should be labeled as RX4/TX4
- CrystalFonz LCD
The software and other files in this repository are released under what is commonly called the MIT License. See the file LICENSE in this repository.