One person asked me whether any of the low cost boards in my Raspberry Pi Zero vs CHIP vs Orange Pi One comparison post came with GPS, and the answer is not without some external hardware. The only low cost boards with GPS I could think of were LinkIt ONE and NavSpark. I wrote about the latter over 2 years ago when the board launched via a crowdfunding campaign, so I went to the update page to find out more about the current status, and found two updates made in the last 6 months, including one about Navspark mini, a tiny board with GPS support, removing the USB port and having fewer I/Os compared to its older brother.
NavSpark mini specifications:
- MCU – Skytraq Venus828F 32bit LEON3 Sparc-V8 MCU @ 100MHz with IEEE-754 Compliant Floating Point Unit, 1024KB Flash Memory, and 212KB RAM
- 167 channel Venus 8 engine
- Uses GPS, SBAS, QZSS signals
- 1 ~ 10 Hz update rate
- Position accuracy 2.5m CEP
- Velocity accuracy 0.1m/sec
- Warm start TTFF under open sky 29sec average
- Cold start TTFF under open sky 30sec average
- Cold start sensitivity -148dBm
- Tracking sensitivity -165dBm
- Operating range – Altitude < 18km OR speed < 515m/sec (1854 km/h), but not both simultaneously
- Expansion Headers – 2x 6-pin header with full duplex asynchronous UART, 1x SPI shared with GPIO, 1x 2-wire interface shared with GPIO
- Misc – Atomic clock synchronized P1PPS time reference with +/-10nsec accuracy
- Dimensions – 17 x 17 mm
The board is compatible with Arduino 1.6.5 for Linux and Windows, and functionally compatible with NavSpark, and in theory all you have to do is to add the Board Manager URL for NavSpark in the IDE, install the compiler, and follow the instructions in the tutorial. That said tutorial however mentions that “If you own a NavSpark-mini, the following example is not compatible with NavSpark-mini. Please refer to our user guide and Tutorial 2“, the latter explaining how to configure UART1 . The documentation in the tutorials is a little confusing, so it’s better to download the user guide from the resource page that clearly explains how to setup NavSpark mini, and provide links to required tools.
In a separate comment in the blog post announcement, further differences are noted:
The Venus828F on the NavSpark-mini is actually a GPS/Beidou receiver. Due to different RFIC used inside, the Arduino NavSpark-BD library cannot work with Venus828F, but the Arduino NavSpark (GPS) library does work with Venus828F.
Default shipped firmware on NavSpark-mini is GPS/Beidou firmware having GP prefix, making its NMEA output compatible with conventional GPS receivers. Users can easily hook up UART output to their application controller and use it as a GPS or GPS/Beidou receiver module; or connect via PL2303 UART-to-USB adapter to evaluate performance on a PC, or using Arduino NavSpark library to use it as a development board with GPS.
Currently we don’t have a definite plan for a 7mm x 7mm module supporting GLONASS or Galileo yet.
NavSpark mini module sells in a pack of 6 for $36, hence the $6 price tag, but there’s also a page where it is just given away for free with a USB to TTL debug board, and all you need to pay is $10 (without tracking) or $20 (Fedex) for shipping. This was announced 5 months ago on the Indiegogo page, but I tried today, and the order went through. It will probably be taken down soon. One important detail is that you ‘d have to order a $9 antenna too, unless you already have GPS/Beidou antenna with u.FL connector. I have the one that was included with LinkIt One, which I hope will work too, so I skipped it.