VBat
R22 and R23 form a voltage divider for our battery measurements. These use the very precise on-board VRef, but each are only 1% toleranced. 11M in stock. Low price. Do we want/need higher precision?
Combining 1% errors to 2% would give us the difference between 4.4V and 4.6V when the logger has 4.5V remaining.
Optional voltage-divider element for ADC
R24 is used as an optional voltage-divider element for use with the 18-bit ADC. CRT0603-BY-1002ELF: 43K in stock.. 0.1% tolerance. More expensive.
Using this for the battery would give a reading between 4.49V and 4.51V when it is at 4.5V.
Suggestion
I think that we should either keep things as they are (for price) or we should unify towards the higher precision option.
Based on the price difference (ca. 20 cents), I suggest that we unify for simplicity and for higher precision to the CRT0603-BY-1002ELF.
VBat
R22 and R23 form a voltage divider for our battery measurements. These use the very precise on-board VRef, but each are only 1% toleranced. 11M in stock. Low price. Do we want/need higher precision?
Combining 1% errors to 2% would give us the difference between 4.4V and 4.6V when the logger has 4.5V remaining.
Optional voltage-divider element for ADC
R24 is used as an optional voltage-divider element for use with the 18-bit ADC. CRT0603-BY-1002ELF: 43K in stock.. 0.1% tolerance. More expensive.
Using this for the battery would give a reading between 4.49V and 4.51V when it is at 4.5V.
Suggestion
I think that we should either keep things as they are (for price) or we should unify towards the higher precision option.
Based on the price difference (ca. 20 cents), I suggest that we unify for simplicity and for higher precision to the CRT0603-BY-1002ELF.