Espressif Systems ESP32 Series - ESP32 as a Slave Device; Electrode Pattern Requirements

2. Schematic Checklist and PCB Layout Design
Figure 21: Electrode Pattern Requirements
PCB Layout
The following are general guidelines to routing traces:
• The trace length should not exceed 300 mm.
• The trace width (W) can not be larger than 0.18 mm (7 mil).
• The alignment angle (R) should not be less than 90°.
• The trace-to-ground gap (S) should be in the range of 0.5 mm to 1 mm
• The electrode diameter (D) should be in the range of 8 mm to 15 mm.
• Hatched ground should be added around the electrodes and traces.
Figure 22: Sensor Track Routing Requirements
Note:
For more details on the hardware design of ESP32 touch sensor, please refer to ESP32 Touch Sensor Application Note.
2.2.2 ESP32 as a Slave Device
When ESP32 works as a slave device in a system, the user needs to pay more attention to signal integrity in the
PCB design. It is important to keep ESP32 away from the interferences caused by the complexity of the system
Espressif Systems 16 ESP32 Hardware Design Guidelines V2.7