Update README.md

Author: roscoe81

README.md

@@ -6,7 +6,7 @@ Remotely monitors and controls a Mercedes-Benz Wallbox Home EV Charger via The T
 
 This monitor allows [Home Manager](https://github.com/roscoe81/Home-Manager) to interwork with an EV charger over LoRaWAN via The Things Network. It can monitor the state of the EV charger, as well as performing lock outlet, unlock outlet and reset charger commands using the EV charger's Modbus RS485 interface (* See note about downlink command timing). The Things Network is used to support charger locations that aren't able to provide wifi coverage (e.g. in a basement garage). It requires customised TTN payload formats that can be found [here](https://github.com/roscoe81/ev-charger-monitor/tree/main/TTN%20Payload%20Formats) and the setup of a mosquitto bridge on the Home Manager side of the system.
 
-* Note that the TTN functionality provides timely uplinking of charger state data, but downlink data (i.e. commands to the charger) are only sent after an uplink message. Therefore commands to the charger are not sent immediately and will be delayed. This does impact the functionality, but it's been minimised by varying the loop timings, based on the charger state.
+* Note that the TTN functionality provides timely uplinking of charger state data, but downlink data (i.e. commands to the charger) are only sent after an uplink message. Therefore commands to the charger are not sent immediately and will be delayed. This does impact the functionality, but it's been minimised by varying the state heartbeat frequency, based on the charger state.
 
 ## Hardware
 ![Hardware](https://github.com/roscoe81/ev-charger-monitor/blob/main/Photos/IMG_5237.jpg)
@@ -17,29 +17,31 @@ The [monitor](https://github.com/roscoe81/ev-charger-monitor/tree/main/Photos) u
 ## Operation
 The system can sense the following charger states:
 
-1. "Not Connected": The EV is not connected to the charger
+1. "Not Connected": The EV is not connected to the charger. Charger state heartbeats are sent over TTN every 2 hours when in this state.
 
-2. "Connected and Locked": The EV is connected to the charger and the key switch on the charger has not been turned to start charging
+2. "Connected and Locked": The EV is connected to the charger and the key switch on the charger has not been turned to start charging. Charger state heartbeats are sent over TTN every 5 minutes when in this state.
 
-3. "Charging": The charger is charging the EV battery
+3. "Charging": The charger is charging the EV battery. Charger state heartbeats are sent over TTN every 15 minutes when in this state.
 
-4. "Charged": The EV is charged to the required level. This state is normally triggered by the EV advising the charger.
+4. "Charged": The EV is charged to the required level. This state is normally triggered by the EV advising the charger. Charger state heartbeats are sent over TTN every 30 minutes when in this state.
 
-5. "Disabled": The charger has been set to "Lock Outlet" or "E0" mode and is disabled.
+5. "Disabled": The charger has been set to "Lock Outlet" or "E0" mode and is disabled. Charger state heartbeats are sent over TTN every 15 minutes when in this state.
 
 6. "E2": Not currently used but allows for future maintenance activity enhancements (e.g. setting Device ID).
 
 The system has the following control functions (* See above note about command timing):
 
 1. "Reset Charger": It's found that this can be used to commence EV charging when the charger is in the "Connected and Locked" state - even if the charger's key switch is still in the locked state.
 
-2. "Lock Outlet": Places the charger in an error mode and interrupts the charging process. This shouldn't be necessary because the EV will stop the charging process when the desired charge level is met.
+2. "Lock Outlet": Places the charger in an error mode (E0)and interrupts the charging process. This shouldn't be necessary because the EV will stop the charging process when the desired charge level is met.
 
-3. "Unlock Outlet": Takes the charger out of error mode
+3. "Unlock Outlet": Takes the charger out of error mode (E0).
 
-ACKs are uplinked via TTN when each control command has been received. There's the potential to add Status Report and Serial Number/Device Type request commands in the future.
+ACKs are uplinked via TTN when each control command has been received.
 
-The charger states can be monitored and charger commands can be sent by using the Apple Home [App](https://github.com/roscoe81/ev-charger-monitor/blob/main/Photos/IMG_5273.PNG) and [Home Manager](https://github.com/roscoe81/Home-Manager). They can also be used to schedule charging using an Apple Home App Automation.
+There's the potential to add Status Report and Serial Number/Device Type request commands in the future.
+
+The charger states can be monitored and charger commands can be sent by using the Apple Home [App](https://github.com/roscoe81/ev-charger-monitor/blob/main/Photos/IMG_5273.PNG) and [Home Manager](https://github.com/roscoe81/Home-Manager). They can also be used to schedule charging times to benefit from time-of-use electricity tariffs, through an Apple Home App Automation. Other monitoring and control apps could be developed by using the TTN API(mqtt).
 
 ## License
 This project is licensed under the MIT License - see the LICENSE.md file for details