Mooper
Member
This is daftmike's low battery indicator mk2, I just made it smaller. Thought I would share.
Original post
V2 uses an adjustment pot to allow you to set the low voltage level more easily.
Here it is: https://oshpark.com/shared_projects/3m831fzw
Dimensions: 0.56x0.51 inches (14.12x12.90 mm)
Here's V3: https://oshpark.com/shared_projects/JM1rsFmC
Dimensions: 0.45x0.38 inches (11.40x9.73 mm)
V3 requires you to do a bit of math and some tight soldering. The pot is replaced with 2 resistors. If you know at what voltage you want the LED to go from green to red, just plug it in to the formula.
0.6v=Vlow*R2/(R1+R2)
OR forget the formula and just change the underlined portion of this url to your desired low voltage level.
https://www.wolframalpha.com/input/?i=0.6%3D10.6*x%2F(10000%2Bx)
Start with 10k for R1.
X will be R2
V3
Original post
V2 uses an adjustment pot to allow you to set the low voltage level more easily.
Here it is: https://oshpark.com/shared_projects/3m831fzw


Dimensions: 0.56x0.51 inches (14.12x12.90 mm)
Here's V3: https://oshpark.com/shared_projects/JM1rsFmC


Dimensions: 0.45x0.38 inches (11.40x9.73 mm)
V3 requires you to do a bit of math and some tight soldering. The pot is replaced with 2 resistors. If you know at what voltage you want the LED to go from green to red, just plug it in to the formula.
0.6v=Vlow*R2/(R1+R2)
OR forget the formula and just change the underlined portion of this url to your desired low voltage level.
https://www.wolframalpha.com/input/?i=0.6%3D10.6*x%2F(10000%2Bx)
Start with 10k for R1.
X will be R2

V3