Hardware Reference
In-Depth Information
4.
Now you need to install a resistor. This resistor is the pull-up resistor. You must insert it
between pin 2 and pin 3. Place this close to the edge of the board. Have a look at
Figure
3-10
for an example of a good placement. Why is that a good place? This is the
pull-up resistor and it needs to follow the connection from the Raspberry Pi's GPIO pin.
If you were to place the resistor before the connection your sensor won't work.
Figure 3-10.
Good resistor placement
5.
After this, you insert a hook-up wire from between the sensor and the resistor to P1-07
(GPIO-4) on the Raspberry Pi. In Figure
3-11
you can see the final connection.
In Figure
3-11
you can see you have used all three pins (this is standard mode, remember).
In a multidrop long-range deployment that would be a lot of wires! This is where the
parasite mode comes in.