Page 92 - Programming the Photon Getting Started With the Internet of Things

accordingly. Because the value we read from the potentiometer and the value we want to
write to the servo are very different, we can use a simple programming technique to scale

down the value. The hardware we will be using for this experiment is shown in Table 4.6.

Schematic Description Appendix

M1 Photon board M1

Breadboard H1

Jumper wires H2

Servo motor H5

10-K potentiometer R2

Table 4.6 Hardware and Components

It’s quite simple to connect the servo to the Photon board: connect the black or brown

cable to any ground pin (GND), connect the red cable to the 5-V reference pin (VIN), and
then finally connect the yellow cable to one of the analog pins, which will actually use
PWM because we are sending a pulse to the servo. The potentiometer is wired in a similar
way, where one of the pins is connected to ground, another is connected to 3.3 V, and the

middle pin is usually connected to one of the analog input pins on the Photon so we can
read its value. You can connect the potentiometer and the servo according to Figure 4.12.