v2.0.8 - add SPI support

Author: PaulZC

README.md

@@ -17,7 +17,7 @@
   </tr>
 </table>
 
-u-blox makes some incredible GNSS receivers covering everything from low-cost, highly configurable modules such as the SAM-M8Q all the way up to the surveyor grade ZED-F9P with precision of the diameter of a dime. This library focuses on configuration and control of u-blox devices over I<sup>2</sup>C (called DDC by u-blox) and Serial. The UBX protocol is supported over both I<sup>2</sup>C and serial, and is a much easier and lighterweight interface to a GNSS module. Stop polling messages and parsing NMEA data! Simply ask for the datums you need and receive an automatic callback when they arrive.
+u-blox makes some incredible GNSS receivers covering everything from low-cost, highly configurable modules such as the SAM-M8Q all the way up to the surveyor grade ZED-F9P with precision of the diameter of a dime. This library supports configuration and control of u-blox devices over I<sup>2</sup>C (called DDC by u-blox), Serial and - as of v2.0.8 (thank you @aberridg) - SPI too! The UBX protocol is a much easier and lighterweight interface to a GNSS module. Stop polling messages and parsing NMEA data! Simply ask for the datums you need and receive an automatic callback when they arrive.
 
 This library can be installed via the Arduino Library manager. Search for **SparkFun u-blox GNSS**.
 
@@ -53,6 +53,18 @@ Migrating to v2.0 is easy. There are two small changes all users will need to ma
 
 If you are using the Dead Reckoning Sensor Fusion or High Dynamic Rate messages, you will need to make more small changes to your code. Please see the [dead reckoning examples](./examples/Dead_Reckoning) for more details. There is more detail available in [Theory.md](./Theory.md#migrating-your-code-to-v20) if you need it.
 
+## SPI Support
+
+In v2.0.8 we added support for SPI, based on a contribution by @aberridg. Thank you Andrew!
+
+We have tested the SPI interface on as many platforms and modules as we could pull together. It works perfectly on most but not quite all combinations.
+For reasons we don't understand yet, the ZED-F9P and Teensy 3.2 don't seem to get along. But Teensy 3.2 and the ZOE-M8Q do play nicely together.
+If you notice a combination that does not seem to work, please raise an [issue](https://github.com/sparkfun/SparkFun_u-blox_GNSS_Arduino_Library/issues) and we will investigate.
+
+The SPI examples have their [own folder](./examples/SPI).
+
+Please check the module datasheets for details on what clock speeds and data rates each module supports. The maximum clock speed is typically 5.5MHz and the maximum transfer rate is typically 125kBytes/s.
+
 ## Max (400kHz) I<sup>2</sup>C Support
 
 To achieve 400kHz I<sup>2</sup>C speed please be sure to remove all pull-ups on the I<sup>2</sup>C bus. Most, if not all, u-blox modules include internal pull ups on the I<sup>2</sup>C lines (sometimes called DDC in their manuals). Cut all I<sup>2</sup>C pull up jumpers and/or remove them from peripheral boards. Otherwise, various data glitches can occur. See issues [38](https://github.com/sparkfun/SparkFun_Ublox_Arduino_Library/issues/38) and [40](https://github.com/sparkfun/SparkFun_Ublox_Arduino_Library/issues/40) for more information. If possible, run the I<sup>2</sup>C bus at 100kHz.

library.properties

@@ -1,9 +1,9 @@
 name=SparkFun u-blox GNSS Arduino Library
-version=2.0.7
+version=2.0.8
 author=SparkFun Electronics <techsupport@sparkfun.com>
 maintainer=SparkFun Electronics <sparkfun.com>
 sentence=Library for I2C and Serial Communication with u-blox GNSS modules<br/><br/>
-paragraph=An Arduino Library to enable both I2C and Serial communication for both NMEA reception and binary UBX sending to u-blox modules. Useful for interfacing to the <a href="https://www.sparkfun.com/products/15136">SparkFun GPS-RTK2</a> ZED-F9P, <a href="https://www.sparkfun.com/products/15005">SparkFun GPS-RTK</a> NEO-M8P-2, the <a href="https://www.sparkfun.com/products/15210">SparkFun SAM-M8Q</a>, and the <a href="https://www.sparkfun.com/products/15193">SparkFun ZOE-M8Q</a>. Library also works with other u-blox based boards.<br/><br/>The ZED-F9P and NEO-M8P-2 modules are top-of-the-line modules for high accuracy GNSS and GPS location solutions including RTK. The ZED-F9P is unique in that it is capable of both rover and base station operations allowing the module to become a base station and produce RTCM 3.x correction data.<br/>
+paragraph=An Arduino Library to enable I2C, Serial and SPI communication for both NMEA reception and binary UBX sending to u-blox modules. Useful for interfacing to the <a href="https://www.sparkfun.com/products/15136">SparkFun GPS-RTK2</a> ZED-F9P, <a href="https://www.sparkfun.com/products/15005">SparkFun GPS-RTK</a> NEO-M8P-2, the <a href="https://www.sparkfun.com/products/15210">SparkFun SAM-M8Q</a>, and the <a href="https://www.sparkfun.com/products/15193">SparkFun ZOE-M8Q</a>. Library also works with other u-blox based boards.<br/><br/>The ZED-F9P and NEO-M8P-2 modules are top-of-the-line modules for high accuracy GNSS and GPS location solutions including RTK. The ZED-F9P is unique in that it is capable of both rover and base station operations allowing the module to become a base station and produce RTCM 3.x correction data.<br/>
 category=Sensors
 url=https://github.com/sparkfun/SparkFun_u-blox_GNSS_Arduino_Library
 architectures=*