Variobot variAnt Instructions Manual page 34

7) Checking the Sensors
Place your ant in a well lit area and check the
values outputted using "printSensors()".
Antennae:
Mandibles:
front legs:
back legs (eyes):
rear part (head):
variAnt's phototransistors are connected in
series between GND and 5 V, and they provide
eight analog voltages or values ranging
between 0 and 1023 (5 V) at the connections
AL0 - AL3 and AR0 - AR3 on the board.
From these 8 values and the maximum value of
1023, 9 difference values are then calculated.
These difference values correspond to the
respective relative shadowing of the sensors
and add up to 1023 in total.
L0 R0
L2 R2
L1 R1
L3 R3
M
The sensor values should change depending on the
ant's orientation.
If a sensor consistently has a high value, it is
either incorrectly polarized or not properly
connected.
Shade one of the sensors with your hand and test if
the corresponding value increases significantly (to
700 - 1000).
The sensors on the hind legs should be shaded
simultaneously with the eye sensors on the same
side, just as the sensor on the rear part and the
central sensor on the head should be.
The 3 additional sensors, which are directly
inserted into the breadboard, are aligned
parallel to the sensors on the hind legs and rear
part.
The sensitivity of the sensors can be adjusted, if
needed, by appropriately shifting the respective
heat shrink tubing.