 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Microcontroller and PC projects : Solar Controller
| Author | Message | ||||
| Phil23 Guru  Joined: 27/03/2016 Location: AustraliaPosts: 1667 |
Hi All, New here & probably about to bite off more than I can chew... Been looking at the MicroMite LCD backpack for a few weeks now & finally built it yesterday. Project I have in mind is a controller for solar water heating on a Spa Tub. Have been heating it & monitoring it for a few weeks, with control being a simple thermostat & plug in timer. Looking to put the Micromite in charge of the task of turning the circulation pump on & off as required, giving it inputs for Air & water temps as well as panel in & out temps. Would also like to add a Solar Irradiance measurement, nothing super accurate, just a small solar panel, so the thing knows the sun is still shining. Currently playing with the ParkAssist code as a starting point, but would be interested in any input other members can provide. Cheers Phil |
||||
crez Senior Member  Joined: 24/10/2012 Location: AustraliaPosts: 152 |
Phil, It shouldn't be too complicated. Add a relay, driver transistor, a couple of thermistors or other temp sensors and your hardware is pretty well done. I made one based on a 68hc908 freescale micro a few years ago. I allow the collectors to reach about 5c above the spa water temperature before the pump starts. the pump is stopped when the collector is 1 degree above the spa. This works pretty well for my setup but could be different for yours. I have about 6 sq m of glass covered collector heating a 1600L spa. Mine is a drain-back system to cope with frost. David |
||||
| Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1667 |
Thanks David. Was planning on having 4 Temp Sensors, DS18B20's. Also a small solar panel (Ex Garden light) as a poor mans Pyranometer to give it an indication of when useful sunlight is or isn't available. Currently have 3 x 2mē polycarbonate glazed panels fed at 360l/hour by a 90 Watt solar circulation pump. The thermostat controlling the pump is at 20cm and I have sensors monitoring water leaving & returning to the spa to observe Delta T (Love Data). Will Post a few pictures sometime later. Cheers Phil |
||||
| paceman Guru Joined: 07/10/2011 Location: AustraliaPosts: 1329 |
Interesting link there Phil - thank you. Greg |
||||
| crez Senior Member Joined: 24/10/2012 Location: AustraliaPosts: 152 |
Phil, It's very much like my system. I have it set up so that the spa electric heater wakes up at around 4pm and makes up the difference if it can if the day has been a bit cloudy. I'm at around 950m above sea level and the system struggles a bit in the winter but we get a fairly good 8 months without much electric assistance. I will be interested how you go with this project. I was playing with the idea of using an SP8266 to grab a weather forecast off the web and use the information to decide whether to employ electric boost or not. David |
||||
| Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1667 |
Hi David, We are at about 590m here & I know I will need electrical assistance on occasions. Ours has an electric heater too, 1000 or 1200 watts, pretty slow to raise the temperature though. Did you see my post on the idea I'm playing with involving a heat pump? Heat Pump Experiments Cheers Phil. |
||||
 Print this page |
 |
The Back Shed's forum code is written, and hosted, in Australia. | © JAQ Software 2025 |
