Attiny85 IR blaster for RGB LED strip control with PIR

Projects General Guidance
1

I've mounted RGB LED strip with IR remote that can control the RGB LED colors, turn them on/off etc. I would like to create a doodad that would have PIR sensor so when it detects movement between set hours, it triggers the LEDs. I have not worked with Attiny85 yet (also what is cheap MCU that is between Attiny85 and Pro mini in terms of pins/size?). The only issue I see is the time keeping stuff, how to set the time, manage sleep etc. when you have so few pins to work with.

From hardware point of view I would need:

Attiny85, PIR sensor board, IR LED, screen, potentiometer, 18650 with charging circuit.

As Attiny85 has limited GPIO I need to think about some workarounds.

I would use a potentiometer and TM1637 to set current time and active time, after that I would disconnect them to save power. The board would have constant power from 18650 battery to keep the time. To activate the time input I think need to move the pot from minmal resistance to max, after that the display would start blinking indicating time input mode, and then maybe use the PIR as button to navigate the "menu" (set current time, set start time, set end time) or remove the module and add a button. I'm not sure how sleep works on Attiny85, if I need to know when it's active so it would register the pot input.

I also would like to add battery voltage indicator, when not in active hours, and if battery voltage less than set treshold, blink yellow LEDs to indicate the need of charge.

6 pins that are available:
PB0 - PIR
PB1 - IR LED
PB2 (ADC1) - Pot
PB3 - Screen
PB4 - Screen
PB5 (ADC0) - Battery voltage

Or I could make pins dual purpose? PB3 could be a button to enter time programming mode, PB0 and PB1 change into screen output.

PB0 - PIR / screen
PB1 - IR / screen
PB2 - pot
PB3 - button
PB4 (ADC2) - battery voltage
PB5 -

Or I could use the RGB strip itself as a screen? Map colors to time and use a button to enter the "menu", the timing wouldnot need to be precise, could assign specific colors to set times.

There are so many options, but I don't have the patience or time to program this little project, I just want it to work.

2

So after some thinking I came up with idea that instead of pot and button or whatever I would use the ir remote and ir receiver where I would program it via the remote on startup, that way I I have to use only 4 pins, pir, ir led, ir receiver and vbat.

On startup the module would go into programming mode where you set time and active hours by using the color buttons on the remote, and if you would like to change the time, you can restart the module so it goes into programming mode again.