Hardware Reference
In-Depth Information
Solution
If you are lucky, you might be able to drive a 5 V device from the Bone's 3.3 V output. Try
it and see if it works. If not, you need a level translator.
What you will need for this recipe:
▪ A PCA9306 level translator (see
“Integrated Circuits”
)
▪ A 5 V power supply (if the Bone's 5 V power supply isn't enough)
The PCA9306 translates signals at 3.3 V to 5 V in both directions. It's meant to work with
I
2
C devices that have a pull-up resistor, but it can work with anything needing translation.
Figure 3-7
shows how to wire a PCA9306 to an LED matrix. The left is the 3.3 V side and
the right is the 5 V side. Notice that we are using the Bone's built-in 5 V power supply.
Figure 3-7. Wiring a PCA9306 level translator to an LED matrix
NOTE
If your device needs more current than the Bone's 5 V power supply provides, you can wire in
an external power supply.
