1.3.0 - Add support for cell modem telemetry and remote configuration to the A2RT. Includes cellular data delivery via raw TCP socket and secure MQTT to VantagePoint, secure remote RTControl access, and NTP clock synchronization. 
      - Add support for clock synchronization via connected A2X for devices not using radio telemetry.
      - Add supervised lead-acid and limited LiFePO4 solar charging on compatible (rev 3.3+) hardware. 
      - Improve measurement, reporting, storage, USB, and long-running operation reliability. 
      - Note: Configuration requires an RTControl version supporting firmware 1.3.

1.2.7 - Fix a bug that would cause SDI12 measurements with a duration longer than the TDMA frame to skip transmit after the measurement sometimes.
      - Fix some issues with SDI12 listen mode.

1.2.6 - Add support for remote control of DOUT pin via serial interface. Allow reporting DOUT state as a sensor.
      - Fix a bug that could lead to slow filesystem performance in the root directory, and bad behavior in RTControl on timeout.
      - Assorted smaller bug fixes

1.2.5 - Fix a bug with the way leap second offsets were calculated when correcting for an incorrect value in the GPS 
        module. This situation should only arise on initial startup of a new unit, but can result in an incorrect
        GPS lock (off by 2 or 4 seconds). 

1.2.4 - Fully implement SDI12 retry pattern, retrying a total of 9 times, instead of 3, when a measurement fails.

1.2.3 - Fix a bug with radio mutex that was causing long press not to work.
        Add channel select support
        Allow "fractional tips" so that a site with a smaller tipping bucket
        can emulate the behavior of a site with a larger one. 

1.2.2 - Fix a bug with FEC modes 1 and 2 that could cause messages to be transmitted in FEC mode 0

1.2.1 - Fix a timing issue that caused communication failure with some SDI-12 devices
      - Fix an issue with extracting negative values from SDI-12 messages
      - Adds retries to SDI-12 communication attempts

1.2.0 - Fix a rare but critical bug that would cause the unit to send undecodable messages until it was reset
      - Add support for mathematical expression parsing and for virtual sensors
      - Changes to support "start of frame timestamping": in start of frame mode: 
          - store a rain total measurement at the start of the frame, and use that later when transmitting
          - log rain value with each measurement
      - Update serial output to allow forwarding from an A2RT to an A2X over serial (for repeater sites with an A2RT present for measurement)
      - Add support for 3-wire tipping bucket (e.g., 5050P)
      - Change status_report_offset to just report_offset, and make it affect all offsets; this way device status and time-based sensor measurements
        will be transmit together at a variable offset.
      - Minor bug fixes (GPS start up, analog measurement retry)

1.1.3 - Changes to support time-series data collection. Add a measurement schedling option that allows taking measurements at the top of the TDMA frame,
        rather than at the TDMA slot. Add a configuration option to report a flag value for SDI-12 sensors when the measurement times out or fails,
        instead of the "no measurement" default. Continue timestampping messages when a clock drifts until is no longer has 1-second accuracy. 
      - Change the way the device handles transmission in "random mode". Now, the MANT PDU will be assembled at the normal transmission time, then a
      delay of up to one TDMA frame length happens. That way, the contents of the MANT PDU match expectations.
      - Fix a bug with setting time via RTControl
      - Fix a bug with SDI-12 measurements that could have caused measurements taken on the second SDI-12 bus to fail. 

1.1.2 - Fix an issue that can cause a restart when sending a GPS sync status message (introduced in 1.1.0)

1.1.1 - Fix an issue that could cause transmissions to stop if the GPS sync finished while a tranmission was in progress. 

1.1.0 - Ensure that finished values (floating point, raw * scale + offset) are used everywhere for local logic (DO, change threshold, etc)
      - Fix an issue with reporting the device serial number
	  - Report both finished value and transmitted value in RT control
      - General bug fixes

1.0.4 - Update calibration factors for analog measurements on newer boards
      - Fix issue with change thresholds interacting with MSR scaling factors that could cause a device to transmit every frame
	  - Log transmission causes

1.0.3 - Include slot time with battery voltage measurement in measurement CSV file
      - Improve GPS robustness in some rare instances

1.0.2 - Fix issue with inverted modulation polarity on radio output

1.0.1 - Add support for latest hardware build (v3)
      - Read solar charge regulator input voltage (under load) and report it
	  on the status page.
	  - Fix issue with SDI12 not working on demo units (hw v1); fix logging
	  issue with SDI12

1.0.0 - Initial release