This is a simple test rig for a little solar tracker I'm building.
Hence the dummy LDR I uploaded yesterday.
Analogue pin A0 for pair 1 & 2
Analogue pin A1 for pair 3 & 4
Test pin 9 (raise to HIGH to test) -Saves power - though not sure how much(!)
Gnd - LDR1 - A0 - LDR2 - +ve(pin9)
Gnd - LDR3 - A1 - LDR4 - +ve(pin9)
TWO Sets of 2 LDRS WITHWIRED IN SERIES BETWEEN +ve (pin9 to HIGH) and Gnd. Pin A0 is central to the two LDRs.
1 ! 4
3 ! 2
1 & 2 is a set, 3 & 4 is a 2nd set.
1 & 3 GND; 2 & 4 +ve (or Check Pin)
A0 High A1 High MA Right
A0 High A1 Low MB Down
A0 Low A1 High MB Up
A0 Low A1 Low MA Left
Other more complex cases: when three are shaded or partially shaded.
Sorryy, This is random tired writing.
I'm turning in for the night.
EurIng Andy Southern
aka Bath Robotics