Will need diode D1 in series with the digital input to block the 12 volts on pin1 of the LM393.
Pullup resistor required on the digital input pin or enable a pullup in the code.
The PIR is read when the digital pin is LOW which happens when the LDR triggers the LM393.
Note the arrangement of R1.

 

Will need diode D1 in series with the digital input to block the 12 volts on pin1 of the LM393.
Pullup resistor required on the digital input pin or enable a pullup in the code.
The PIR is read when the digital pin is LOW which happens when the LDR triggers the LM393.
Note the arrangement of R1.
View attachment 362267

Fantastic!! You and eetech00 are both on board with this. I'll re-post my schematic shortly. Will the pull up be a 1k to 5v?
Any suggestion for the diode to use?

 

1N4148 for D1.
Use a 10K pullup to 5 volts.
The ATtiny has internal pullups that can be enabled in the code eliminating the need for the 10k if desired.

 

Hi guys,
I have addressed your latest comments. Please review. All your help and input is greatly appreciated !!
(file attached)

 

Looks correct.

 

Looks correct.

Great. Thank you so much for all your help.

 

Can I get rid of C1 now that we have eliminated the BS250?
And, can C3 be a 1uF?

 

Is the battery connected to the circuit when charging?

 

Is the battery connected to the circuit when charging?

The battery will be connected to a solar charge controller 24/7 when powering the unit, but will be disconnected when put on a "charger".

 

Then keep the 100uf cap.
Leave C3 at 100nf but should be installed as close as possible to pins 4 and 8 on the ATtiny.

 

Then keep the 100uf cap.

Both, right? C2 & C1?

 

Yes, keep C1 and C3 but move C3 on the pcb as stated in my previous post.

 

Correction: C3 as close as possible to pins 4 and 8 on the ATtiny.

 

Better?

 

Just to verify, I'll need both of these caps? C1 & C2 connecting 12V to GND?

 

I also added a circuit for a low battery function using the LM393 that will ultimately blink the RA rapidly for several seconds when battery is below 11v.
Resistor size is not critical at this point as I will choose and place them myself.

 

That won't work as the reference voltage drops as the battery voltage drops.
Configure using the 5 volt regulator as the source.
Notice pins 5 and 6 reversed from your schematic.

 

That won't work as the reference voltage drops as the battery voltage drops.
Configure using the 5 volt regulator as the source.
Notice pins 5 and 6 reversed from your schematic.
View attachment 362334

Yes, I'm just realizing that. Thx for getting me past that!!

 

That won't work as the reference voltage drops as the battery voltage drops.
Configure using the 5 volt regulator as the source.
Notice pins 5 and 6 reversed from your schematic.

Better?

 

No! Check pin8 and C2 on the LM393.
I gave the correct values for R11 and R12.