So, it's been awhile, but I'm still toying with this project. This is where I am so far:
-Migrated from a standard Arduino to a barebones ATmega328p to save power.
-Burnt a lilypad bootloader onto the 328p so it runs at 3.3V instead of 5v to save power.
-Implemented sleep code (and interrupts) to save power
-Switched to a more accurate DS18B20 temp sensor
-Added a button to manually set number of steps needed to close blinds and save those setting to EEPROM
-Have a (partially) working override button
-Added IR receiver, so I can now open and close with a remote
-Designed a small PCB
I'm still working on running it off solar, which is not going too well. Right now, I my breadboard circuit have it running off a 4.4Ah Lipo battery, using a Lipo Rider Pro (outputs 5v) and a small 2W solar panel and then run through a buck converter down to the 3.3v that I need for the uC, driver and sensors. It can run nearly a month, depending on weather conditions with the panel supplementing the battery.
It's disappointing not to have it work purely off solar since I'm fairly sure I've used all the power saving tricks I can think of. In sleep mode, the circuit is consuming less than 10mA (I blew a fuse in my multimeter, so can't be sure of exactly what I'm using) and roughly 200 mA when the motor is engaged, which at this time of the year is four times a day - each time lasting roughly 5 seconds.
In summary, I still have to work some things out, but thought I'd give an update for anyone else out there who may be working on anything similar!
I've attached two pics -
1: Breadboard so I can play. Running off solar and battery. Using Pololu DRV8834.
2: PCB with remote, using Easydriver.