--- /dev/null
+Exanh Gardener soil moisture sensor support.
+
+Copyright 2017 Nathael Pajani <nathael.pajani@ed3l.fr>
+
+
+/* ****************************************************************************
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *************************************************************************** */
+
+
+This code handles the v0.2 and v0.3 versions of the Exanh Gardener soil
+moisture sensor.
+
+The code also provides support of all three sensors found on exanh sensor board
+in version 0.2 :
+ - BME280 I2C temperature, humidity and pressure sensor
+ - TSL256x I2C luminosity and IR sensor
+ - VEML6070 I2C UV sensor
+
+The default behavior for the sensor does nothing (should enter sleep, but not
+implemented yet).
+When the sensor is not configured (no address set), then all data received on
+serial is silently dropped.
+Pressing the "Mode" button on the sensor for more than 4 seconds sends a "c"
+request on the serial line, changes address to 0 (nul), and enters the
+"address requested" state. The host should then send a message to the sensor on
+it's temporary address, containing it's new address. The message is three bytes
+long and it's format is :
+ # 0 addr
+ 0x23 0x00 (0x01 to 0x1F)
+Addresses are between 1 and 31, allowing up to 30 sensors on one link.
+
+Once the address is set, the host can request samples data by sending a message
+addressed to the sensor.
+The message is three or more bytes long (depending on the type) and it's
+format is :
+ # addr type [other data]
+ 0x23 (0x01 to 0x1F) (0x00 to 0xFF) [....]
+Valid types are :
+ - 'a' : all - request to send all available sensor data to host.
+ - 'l' : set led color - set the sensor led color. Three bytes of data (RGB).
+
+It is also possible to broadcast a message to all sensors by sending to address
+255 (0xFF)
+
+
+To set the sensor address using a serial line from a linux host, you can use
+these commands (sensor connected to ttyUSB0) :
+
+# For device address 1 (0x01) :
+echo -ne "#\x00\x01" > /dev/ttyUSB0
+
+# For device address 2 (0x02) :
+echo -ne "#\x00\x02" > /dev/ttyUSB0
+
+# and so on ...
+[...]
+
+# To check what these command send if you are not sure :
+echo -ne "#\x00\x01" | hexdump -C
+
+
+When debug is set at compile time, then debug data is sent on UART0
+
+
