Page 407 - Hacking Roomba

388 Appendix A — Soldering and Safety Basics

Cutters and Pliers

A good pair of diagonal cutters (or flush-cut cutters) is essential to trimming part leads. The
diagonal part means the cutting edges are at an angle to the handles, enabling you to more
easily make a flush cut. A decent pair of diagonal cutters is about $6.
Needle-nose pliers are useful for placing parts, bending component leads, holding leads while
soldering, and basically doing all those things your fingers are too big for. They run about
$16 dollars for a decent pair. Figure A-4 shows both cutters and pliers. They last a long time.
The ones in the figure are over a decade old.

FIGURE A-4: Diagonal cutters and needle-nose pliers

Digital Multimeter
A digital multimeter is a Star Trek tricorder in many ways. It can measure DC and AC volt-
age and current, resistance, capacitance, and frequency. It can also test diodes or transistors.
Figure A-5 shows a 20-year-old digital multimeter that’s still going strong. It originally was
several hundred dollars. You can get essentially the same accuracy today with additional func-
tions for about $35. Being able to verify the value of resistors and capacitors is very handy with
these devices, but mostly you’ll use it in continuity mode to check if two points in a circuit are
connected.