Miscellaneous words of wisdom
- No matter what you're building, breadboard it first (well, OK, unless you're building something from a kit).
- If an Nv net project doesn't work reliably, put a small capacitors (0.1 - 1.0 uF) across your core chip's power & ground lines.
- If your project still doesn't run reliably, and involves motors (particularly "hacked" servos), put a small (0.1 - 1.0 uF) non-polar capacitor across each motor's power leads.
- Rechargeable batteries output lower voltages than their "nameplates" would suggest. "9V" rechargeables really output 7.2 - 8.4 V; smaller rechargeables ("1.5 V") really output 1.2 V. See the battery comparison page here.
- Connect all unused inputs (on your Nv net chips) to something. Connect to Vcc, or ground, or another output -- whatever's handy. If you don't do this, the input voltages will float around; the attached inverter can start triggering at a high frequency, leading to high power consumption, noise, and eventual chip death. Don't connect unused outputs to anything.
- When at all possible, build and test your circuits and robots in steps. Temporarily ground unused chip inputs while you build & debug various parts of the overall circuit (otherwise they will interfere with normal circuit operation).
- Be mindful of the influence of measuring gear on a circuit. In particular, Nv net circuits need high resistances (on the order of MOhms) to work. Oscilloscope probes generally have input impedances of either 1 MOhm, or (for x10 probes) 10 MOhms. You'll often need to use some sort of isolation between your circuit and the probes to avoid messing with things (see, for instance, Bruce Robinson's voltage follower circuit).
- Debugging -- I've collected enough debugging tips that I've given this material it's own (budding) page over here...
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