I've two solar charge controllers from EPsolar or EPever as they are sometimes known. They are great and have a COM port for monitoring the performance of the panels and state of the battery etc but it's a pain to drag the laptop out and hook things up just to check the status. The COM port is a RJ45 port which uses the RS485 standard so i investigated commercial offerings but they were extremely expensive and as this was just to make things convenient for a personal home product i didn't fancy paying £50 out for the I began to investigate doing this myself and using some off the shelf components and custom firmware from the guys at esp-link i was able to come up with the design you can see in the picture. I've made both a instructable available here and also a set of YouTube videos on the procedure. http://www.instructables.com/id/Wireless-Solar-Charge-Controller-Monitor-RS485-to-/ http://www.youtube.com/c/ColinHickey1