Silicon Laboratories EFM8BB3-SLSTK2022A User Manual page 8

5.2 Joystick
The kit has an analog joystick with 8 measureable positions. This joystick is connected to the EFM8 on the P1.7 pin and uses different
resistor values to create voltages measurable by the ADC0.
Direction
Center press
Up (N)
Up-Right (NE)
Right (E)
Down-Right (SE)
Down (S)
Down-Left (SW)
Left (W)
Up-Left (NW)
Note:
1. These calculated values assume a VMCU of 3.3 V.
silabs.com | Building a more connected world.
Figure 5.2. Joystick
Table 5.1. Joystick Resistor Combinations
Resistors Combinations (kΩ)
0.1
0.1 + 10
60.4
60.4 + 10
(N // E ) 21.34
=
(N // E ) + 10 21.34 + 10
33
33 + 10
(S // E ) 7.67
=
(S // E ) + 10 7.67 + 10
10
10 + 10
(S // W )
=
(S // W ) + 10 6 + 10
15
15 + 10
(N // W ) 12.01
=
(N // W ) + 10 12.01 + 10
UG125: EFM8BB3-SLSTK2022A User's Guide
Expected UIF_JOYSTICK Voltage (V)
6
Peripherals
1
0.033
2.831
2.247
2.533
1.433
1.650
1.238
1.980
1.801
Rev. 0.7 | 8