Hardware Reference
In-Depth Information
The flow of electricity can cause heating, which will either cause burns to your body (some-
times deep within tissue) or can cause a fire.
Electricity can kill! Only experiment with low voltages and currents, and never work with
mains. If you are ever in doubt then you should check with someone suitably qualified.
WARNING
Hardware is less forgiving than software; if you make a mistake with code, you might get an
error, the program might crash, or in rare cases you might cause your Raspberry to reset. If
you make a mistake in hardware then you can cause permanent damage. As such, hardware
engineers tend to check and double check their work before applying the power!
When experimenting you should beware of short-circuiting your projects. Make sure that
nothing conductive touches your circuit. Tools, metal watchstraps and jewellery, unused
wires, spare components and tin foil have all been known to damage circuits. Keep your
working area clear of anything you don't need and make sure that nothing metallic can touch
your Raspberry Pi or circuit.
Static Discharge
You may have felt a small electric shock due to static sometimes. This occurs when a charge
builds up and then discharges to a conductor, which you feel as a small shock. If you are hold-
ing a component when this happens, that large voltage will flow through the component and
damage it. Other objects such as plastic can become charged too and then discharge through
a component. As such, you should take care to avoid this static discharge through compo-
nents or circuits. In industry, conductive work surfaces and wrist straps are earthed to pre-
vent static buildup. This may be an extreme solution for a hobby; you can discharge yourself
by touching something earthed like a water tap, and avoid working on surfaces that are
prone to picking up static charge like plastics - for example, avoid working on nylon carpets
or plastic bags.
You may have noticed components are supplied in antistatic bags, or static-dissipative bags or
static-barrier bags. These bags are made from special plastic designed to protect the contents
from being zapped by static discharges and conduct any charge away. Beware that some of
these bags can be slightly conductive and so may interact with your powered-up circuit.
TIP
