Hardware Reference
In-Depth Information
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pins 1, 2, and 3 are not ground pins at all. these three pins select the i2C address. You can configure part of
the address of the i2C device using these pins. as i am only going to have one device on my i2C bus at the moment, i will
tie all the address pins to ground. this has the effect of pulling them down. the result is a low bit address. there would
be nothing stopping me tying them to the 3.3-v vcc. this would have the effect of pulling all address bits high. You could
also mix high and low on each address pin.
Note
3.
Let's move on from the address selection pins. You can see that I have connected pin 16
to the 3.3-V Vcc on the breadboard. Next up in Figure
4-14
I have added my power source
and connected the hook-up wire to the 3.3-V source for the LCD logic and the 5-V source
for the LCD backlight. In Figure
4-14
the power rails closest to the USB port are set to 3.3 V
and the rails on the other side are set to 5 V.
Figure 4-14.
Power source added to the breadboard
4.
Lastly, in Figure
4-15
I add in the hook-up wire for the I2C lines and the lines for the LCD.
