Python for Secret Agents - Volume II

Collecting bulk data with the Arduino

First, we'll expand our IR sensor reading sketch to wait for the sensor to show a stable reading. We'll use this stable reading algorithm to gather a batch of 16 samples from the sensor. This will give us some data that we can use for calibration.

The expanded version of the gather_data() function includes three separate features. We've left them in a single function, but they can be decomposed if required to make the Arduino more responsive. Here are the global variables shared by gather_data() and share_data():

unsigned long start_time, end_time;
int raw_reading;
#define MODE_LIMIT 6
int reading[MODE_LIMIT];
int count[MODE_LIMIT];

const int TIME_LIMIT = 5000; // Microseconds.

We defined three important features ...