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Wiring
Single System Circuit
This circuit is used in the first series of projects:
The list of parts required includes:
| Quantity | Part | Description |
|---|---|---|
| 2 | 470 ohm | Current Limiting resistors |
| 2 | LED | LED |
| 1 | NO Momentary | Pushbutton or switch |
| 1 | ATMega328P | Arduino Uno, nano or any other 16MHz ATMega328P dev board |
Note this guide uses specific hardware capabilities. These are available on most MCU's but the setup and pinouts will differ. As such, the guide can be implemented on other platforms, but it is prepared with the ATMega328P in mind. Therefore it is recommended that if you follow along with this guide you use an Uno or at least If you use another platform then you will need to adapt the instructions to suit.
Following is a diagram of the circuit.
Dual Systems - Communications circuit
This circuit is used in the final series of projects, specifically the Receivers which is used to receive a signal from one of the Sender programs,
In addition to the parts listed above, you will also need the following:
| Quantity | Part | Description |
|---|---|---|
| 1 | 10K ohm | Current Limiting resistors |
| 1 | ATMega328P | Arduino Uno, nano or any other 16MHz ATMega328P dev board |
Following is a diagram of the circuit.
About the connection between the two Arduinos.
You must connect the grounds between the two Arduinos. It is as simple as that, if you don't, it will likely result in random behaviour or possible even damage either or both of the Arduinos.
The common ground provides a means for the two Arduinos to "agree" on what a zero or LOW is, and thereby what a +5V or HIGH is. It is important that you connect the grounds together.
Do we need the 10K resistor?
No, we do not need the 10K resistor.
Why is it there?
Safety. If for some reason I inadvertantly loaded a pair of programs that
configured the interconnected pins (i.e. 4 on the sender, 2 on the receiver)
as OUTPUT, then there would be risk of a short circuit between the two.
In the unlikely event that that program configuration did occur, the 10K
resistor guards against that.
If you do not have a 10K resistor, you can use a smaller one (e.g. down to
say 470ohm) or leave it out altogether (not recommended for the reason I
just stated).
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