arduino

A reader of my book Arduino Projects To Save The World recently asked me about the DHT11 and DHT22 sensors. In particular, how to connect multiple sensors (and how to write the code for it) to an Arduino. I must admit I had never considered it. I have used them plenty of times, but not in parallel. Turns out, Adafruit's DHT library makes it super easy.

After performing a demonstration of the version 0.9 code and hardware to the hackerspace a few months back, I finally got around to finishing up the major features, dressing it and calling it done (for now).

I admit to some lazyness, but the winter holidays played some part in my delay.

The purpose of this blog is to illustrate how to go about bringing up a project step by step.

In this step of the THS Membership Box, we wire up the bill acceptor to the Arduino and start some very simple Arduino code.

The bill acceptor output is a pulse, which starts high, then drops to a logic low for a short period of time before returning to high. I have already set the bill acceptor and tested it to output 1 pulse per 1000 yen. Thus, a 1000 yen bill outputs 1 pulse, a 5000 yen bill outputs 5 pulses and a 10000 yen bill outputs 10 pulses.

Here is a shot of the insides of my quiz show box.

Lots of space in there! The arduino is bolted to the metal base plate. The shield is only there to provide a strong attachment point for the wires. Unfortunately, I only had solid core bell wire, so the cabling is quite stiff and hard to work with. Next time I'll use ribbon cable!