add linux README

diff --git a/linux/README.md b/linux/README.md
new file mode 100644 (file)
index 0000000..81ed199
--- /dev/null
+++ b/linux/README.md
@@ -0,0 +1,27 @@
+= Host side of the pulse counter infrastructure. =
+
+pulsecounter.c is modelled after BlueZ' gatttool. Because of "strange"
+design of BlueZ tools, it is not sufficient to use the library that
+gets installes with it. Complete source installation is necessary.
+
+So, unpack, configure *and build* BlueZ source (do not `make install`).
+In this directory, run `make BLUEZ=/path/to/top/of/bluez/source`. You
+will get the `pulsecounter` binary.
+
+Currently (2015-12-21) supplied database adapter uses MySQL(/MariaDB).
+Confiruration file (default path `/etc/pulsecounter.db`) contains lines
+of this format:
+
+    key SPACE* [=:]* SPACE* value
+
+Lines are analyzed up to the '#' character (comment separator).
+There is no escaping.
+
+Keys are:
+
+    host       hostname, NULL if not specified (meaning local database).
+    user       database user name, NULL if not specified
+    password   database password, NULL if not specified
+    database   database name, "watermeter" if not specified.
+
+