Add CLI args for configurable values

README.md

@@ -38,7 +38,7 @@ solax2mqtt/<adapter-serial>/SENSOR/inverter {
 
 Most of the data for this project came from [`squishykid/solax`](https://github.com/squishykid/solax).
 
-Configuration is currently done by editing the source code and recompiling.
+## Alternatives
 
 PocketWIFI is dreadfully insecure. Use Modbus-RTU or, at the very least, a
 PocketLAN, if you can. I'll be switching as soon as I'm able to.
@@ -48,9 +48,29 @@ This is effectively a custom PocketWIFI module built out of an ESP8266. It's
 possible I could put one of these together and make it talk MQTT instead of
 having this separate daemon running. One for later.
 
-The PocketWIFI squirts MQTTS to their cloud servers, but they don't verify TLS
-so it can be trivially intercepted. However, the messages are in a useless (to
-me) binary format.
+The PocketWIFI squirts MQTTS to their cloud servers and don't verify TLS, so it
+can be trivially intercepted. However, the messages are in a useless (to me)
+binary format.
+
+## Usage
+
+First, get TCP access to the PocketWIFI module. Over the AP, it's at `5.8.8.8`.
+If you tell it to connect to your WIFI network, your DHCP server will assign an
+IP. Next, run `solax2mqtt`:
+
+```
+solax2mqtt --mqtt-url tcp://<host>:<port> \
+           --solax-url http://<host>[:port] \
+           --solax-password <admin-password>
+```
+
+That's it. Errors will be outputted to the console; failure to connect to the
+Solax is not fatal (it will keep retrying). Failure to connect to the MQTT
+server is (the process will exit).
+
+You can also solax2mqtt --help` to see a few other options.
+
+## `mqtt2prometheus`
 
 Once the metrics are in MQTT, they can be sent to prometheus using
 [`mqtt2prometheus`](https://github.com/hikhvar/mqtt2prometheus):