Page 183 - Programming the Photon Getting Started With the Internet of Things

Figure A.4 A typical multimeter.

In order for us show to you how a multimeter works, it is important to understand what
we are measuring such as voltage, current, or resistance:

Voltage is how hard the electricity is being pushed through a circuit—a higher
voltage is being pushed through a circuit really hard. Voltage uses the symbol V.

Current is how much electricity is flowing through a circuit—a high current
indicates that more electricity is flowing through. The symbol for current is A.

Resistance is how difficult it is for electricity to flow through a circuit—a higher
resistance indicates that it is much more difficult for it to flow through. Resistance is

measure in ohms, and the symbol for resistance is Ω.

It is also worth noting that the symbol that is being used for a unit may differ from a
symbol for a variable equation.

Soldering

Learning how to solder is an essential skill in the world of electronics. Although you can
get by just using a prototyping board, you may still need to solder headers onto the board
or make some small modifications to a component.

Solder refers to the alloy that typically comes on a wire spool or tube, and it is this

solder that we use to fuse components together on a printed circuit board. When selecting