another up date for anyone still following this thread.....
well had a failure, nothing critical, but the buttons I chose for the control panel, nice chrome, with integrated blue led, supposed to be ip67 rated, one has failed and another is suspect, changed them as I had spares, but now not happy with the buttons, may have to go back to my first idea of membrane keyboard, expensive to have a one off made, so it maybe an off the shelf solution with an overlay..
on the web..
added the Ethernet shield and now the tub is on the web , web page is hard coded at the mo, but perfectly functional, I can check the status, temp, set temp, outdoor temp, time, and change mode and temperature.
I was going to move the code to an html file on the sd card reader, but for now it all works well as is, not done anything with HTML so another learning curve.
up and coming improvements
started to add support for the nextion range of colour touchscreen displays.
got a few minor bugs to iron out , well some are more improvements than bugs....
going to add a multi timer that can be user set to trigger mode / temp changes ..
as I will be re thinking the keypad, going to add volume +/- , will use this to drive a separate audio amp for the speakers I have close to the tub, planning on using the adfruits 20w i2c class D amp
think I will drop the SMS system, its still flaky , the Webserver is much more stable