ESP32-S3 PinPulse Shield pinout

InteractiveOpen the S3 PinPulse in 3DTurn the real board over and click any of its 44 holes. Every pad is placed from this design’s own net list.Open in 3D →

Reading this board

The shield has no chip of its own. An ESP32-S3 Gold Edition plugs into the socket down the middle, antenna end toward the display connector, and the shield brings each of its 44 header pins out twice: once on a male pin at the outer edge, once on the yellow female socket beside it. The two rows on each side are the same nets, hole for hole, so there are 88 holes and 44 pins: 36 GPIO and eight power.

The order is the S3 Gold's own, read from this design's net list, so anything that is true of a pin on the S3 Gold pinout is true of the same pin here. The one difference in print is that this silkscreen labels the serial pins 43 and 44 rather than TX and RX. Open the shield in 3D and click either row; the handbook covers using it.

The LEDs

Every GPIO has an LED, lit while the pin is high. The pin does not drive it. Each GPIO goes to one input of a 74HC04 inverter (six chips, 36 gates), the gate output sinks the LED, and the LED's anode goes to 3.3 V through 5.1 kΩ. A high pin pulls the gate output low and the LED lights.

What that costs the pin is one CMOS input: at most 1 µA of leakage and 10 pF. A sensor, a bus or a PWM output does not notice it, and the LED current comes off the 3.3 V rail through the inverter rather than out of the GPIO. Any visible LED drops at least 1.5 V, which leaves under 0.4 mA each, so all 36 lit draw less than 15 mA.

The cost shows up the other way round. A pin nothing is driving flickers. An inverter input left floating picks up whatever is nearby, so a GPIO your sketch never set lights and dims when a hand comes close. The back of the board says as much. Set the pin as an output, or give it INPUT_PULLUP, and it stops. A pin toggling faster than the eye can follow shows as a glow, not a blink.

The marks beside the numbers

The back repeats those buses as text, and one line is misprinted: it reads I2S - SDA(8), SCL(9). It means I²C. It also lists UART as TX 43, RX 44 and native USB as D− 19, D+ 20.

The display connector

A 15-way FPC socket on a 1.0 mm pitch at the top of the board. Nothing switches its lines: all thirteen signals are the same nets as the header holes, so a fitted display owns those GPIOs, and their LEDs show its traffic.

The net list names three of those lines BL, DC and CS: GPIO41, GPIO2 and GPIO10.

What the plugged-in board already uses

The shield adds nothing to any net except its inverter input, so the pins to leave alone are the S3 Gold's. On the N16R8 module it ships with, GPIO35, 36 and 37 carry the octal PSRAM and must not be driven. GPIO0, 3, 45 and 46 are sampled at reset. GPIO19 and 20 are the native USB port, GPIO43 and 44 the serial bridge, and GPIO48 the RGB LED. The table below names each one.

Power

3V3, 5V and RST are the S3 Gold's own pins passed straight through; the shield has no regulator. 3V3 comes from the S3 Gold's AMS1117, and the shield's six inverters and 36 LEDs are on it before you add anything. All four GND pins are the same net, on both rows.

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