Docs: Add factory reset via settings file

nseidle · nseidle · commit a89076100e1c · 2023-06-28T15:58:44.000-06:00
diff --git a/docs/configure_with_settings_file.md b/docs/configure_with_settings_file.md
@@ -6,4 +6,14 @@ Surveyor: ![Feature Partially Supported](img/YellowDot.png) / Express: ![Feature
 
 *SparkFun RTK Settings File*
 
-All system configuration can also be done by editing the *SFE_[Platform]_Settings_0.txt* file (example shown above) where [Platform] is Facet, Express, Surveyor, etc and 0 is the profile number (0, 1, 2, 3). This file is created when a microSD card is installed. The settings are clear text but there are no safety guards against setting illegal states. It is not recommended to use this method unless You Know What You're Doing®.
+All device settings are stored both in internal memory and an SD card if one is detected. The device will load the latest settings at each power on. If there is a discrepancy between the internal settings and a settings file then the settings file will be used. This allows a collection of RTK products to be identically configured using one 'golden' settings file loaded onto an SD card.
+
+All system configuration can be done by editing the *SFE_[Platform]_Settings_0.txt* file (example shown above) where [Platform] is Facet, Express, Surveyor, etc and 0 is the profile number (0, 1, 2, 3). This file is created when a microSD card is installed. The settings are clear text but there are no safety guards against setting illegal states. It is not recommended to use this method unless You Know What You're Doing®.
+
+## Forcing a Factory Reset
+
+![Setting size of settings to -1 to force reset](<img/SparkFun RTK Settings File - Factory Reset.png>)
+
+If the device has been configured into an unknown state the device can be reset to factory defaults. Power down the RTK device and remove the SD card. Using a computer and an SD card reader, open the SFE_[Platform]_Settings_0.txt file where [Platform] is Facet, Express, Surveyor, etc and 0 is the profile number (0, 1, 2, 3). Modify the **sizeOfSettings** value to -1 and save the file to the SD card. Reinsert the SD card into the RTK unit and power up the device. Upon power up, the device will display 'Factory Reset' while it clears the settings.
+
+Note: A device may have multiple profiles, ie multiple settings files (SFE_Express_Settings_**0**.txt, SFE_Express_Settings_**1**.txt, etc). All settings files found on the SD card must be modified to guarantee the factory reset.
diff --git a/docs/img/SparkFun RTK Settings File - Factory Reset.png b/docs/img/SparkFun RTK Settings File - Factory Reset.png
diff --git a/docs/menu_system.md b/docs/menu_system.md
@@ -100,4 +100,6 @@ Factory Defaults will erase any user settings and reset the internal receiver to
 
 If a device gets into an unknown state it can be returned to default settings. Press 'r' then 'y' to confirm. Factory Default will erase any user settings and reset the internal receiver to stock settings. Any settings file and commonly used coordinate files on the SD card associated with the current profile will be removed.
 
-**Note:** Log files and any other files on the SD card are *not* removed or modified.
+**Note:** Log files and any other files on the SD card are *not* removed or modified.
+
+Note: A factory reset can also be accomplished by editing the settings files. See Force a [Factory Reset](https://docs.sparkfun.com/SparkFun_RTK_Firmware/configure_with_settings_file/#forcing-a-factory-reset) for more information. 
