HowTo-Color (8) / Hacking Electronics / Simon Monk / 236-3 / Chapter 8 blind folio 193
8 Hacking with Sensors C
hapters 6, 7, and 8 all overlap somewhat, as many sensors are also modules and both can often be used with an Arduino. In this chapter, we will look at how to use a range of sensors, whether with a little supporting electronics or as an input to an Arduino, or sometimes both.
How to Detect Noxious Gas In this section, you will use a methane sensor (Figure 8-1). While they look like they should be expensive, these sensors are really quite low cost. They include a small heater (connected between the two H connections) and a catalytic sensing element whose resistance changes depending on the concentration of methane. Although the project will run on batteries, it will burn through them pretty quickly because these sensors have a heating element that will consume 150 to 200 mA. The sensing of methane does have lots of sensible scientific and industrial uses. However, we will use this technological know-how for the puerile activity of … detecting farts.
You Will Need To experiment with this gas sensor, you will need the following items.
08-ch08.indd 193
Quantity
Names
Item
Appendix Code
1
D1
LED
K1
1
R1
10kΩ trimpot
K1
1
R2
10kΩ resistor
K2
1
R3
470Ω resistor
K2
1
IC1
LM311 comparator
S7
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