voltage divider calculations

OK, it's not complicated, just rather tedious and repeated application of basic ohms law formula. Your voltage divider will have to have 6 series resistors to obtain your desired five output voltages. First you have to start with what you want the total series resistance to be as that will determine the source impedeance of the network. In the case of arduino analog input pins it's desirable for the driving source to have a 10,000 ohm or less impedenace, so we will set 10,000 ohm for the total series resistance. Do draw a series string of six resistors wired between +5vdc at the top of the top resistor and ground to the bottom of the bottom resistor. Label the resistors R1 to R6 from top to bottom. Next you determine the total series current that will flow through the divider which will be I = 5vdc / 10,000 ohms = .0005 amps. Now starting from the bottom resistor R6 calculate for individual resistor value by voltage drop / series current. So for R6 R= 1.225 / .0005 = 2,450 ohms. Next calculate for R5 which is voltage drop across R5 (1.715 - 1.225) = .490 volts and solve for R5 resistance as .490 / .0005 = 980 ohms. Repeat this process until all the resistors are solved for. A check of your work is to add all the resistors values together and check that the results are equal to 10,000 ohms.

So final answers are:

R1 = 3,630 ohms
R2 = 980 ohms
R3 = 980 ohms
R4 = 980 ohms
R5 = 980 ohms
R6 = 2,450 ohms

I will leave it to you to check my work as it's been many decades sense I had attended my military basic electronics training classes.

Lefty