This page talks about the pins on the CYD.
The connectors are often called "1.25mm JST" but the correct name is "Molex PicoBlade". Chinese clones are sometimes called "mx1.25".
| Connector | Type | Note |
|---|---|---|
| P1 | 4P 1.25mm Molex PicoBlade | Serial |
| P3 | 4P 1.25mm Molex PicoBlade | GPIO |
| P4 | 2P 1.25mm Molex PicoBlade | Speaker |
| CN1 | 4P 1.25mm Molex PicoBlade | GPIO (I2C) |
There are 3 easily accessible GPIO pins
| Pin | Location | Note |
|---|---|---|
| IO35 | P3 Molex PicoBlade connector | Input only pin, no internal pull-ups available |
| IO22 | P3 and CN1 Molex PicoBlade connector | |
| IO27 | CN1 Molex PicoBlade connector |
If you need more than that, you need to start taking them from something else. An SD Card sniffer like mentioned in the Add-ons is probably the next easiest.
After that you're probably de-soldering something!
There are three 4P 1.25mm Molex PicoBlade connectors on the board.
| Pin | Use | Note |
|---|---|---|
| GND | ||
| IO35 | Input only pin, no internal pull-ups available | |
| IO22 | Also on the CN1 connector | |
| IO21 | Used for the TFT Backlight, so not really usable |
This is a great candidate for I2C devices
| Pin | Use | Note |
|---|---|---|
| GND | ||
| IO22 | Also on P3 connector | |
| IO27 | ||
| 3.3V |
| Pin | Use | Note |
|---|---|---|
| VIN | ||
| IO1(?) | TX | Maybe possible to use as a GPIO? |
| IO3(?) | RX | Maybe possible to use as a GPIO? |
| GND |
The CYD has two buttons, reset and boot.
| Pin | Use | Note |
|---|---|---|
| IO0 | BOOT | Can be used as an input in sketches |
The speaker connector is a 2P 1.25mm Molex PicoBlade connector that is connected to the amplifier, so not usable as GPIO at the speaker connector
| Pin | Use | Note |
|---|---|---|
| IO26 | Connected to amp | i2s_set_dac_mode(I2S_DAC_CHANNEL_LEFT_EN); |
If your project requires additional pins to what is available elsewhere, this might be a good candidate to sacrifice.
Note: LEDs are "active low", meaning HIGH == off, LOW == on
| Pin | Use | Note |
|---|---|---|
| IO4 | Red LED | |
| IO16 | Green LED | |
| IO17 | Blue LED |
Uses the VSPI Pin names are predefined in SPI.h
| Pin | Use | Note |
|---|---|---|
| IO5 | SS | |
| IO18 | SCK | |
| IO19 | MISO | |
| IO23 | MOSI |
| Pin | Use | Note |
|---|---|---|
| IO25 | XPT2046_CLK | |
| IO32 | XPT2046_MOSI | |
| IO33 | XPT2046_CS | |
| IO36 | XPT2046_IRQ | |
| IO39 | XPT2046_MISO |
| Pin | Use | Note |
|---|---|---|
| IO34 |
Uses the HSPI
| Pin | Use | Note |
|---|---|---|
| IO2 | TFT_RS | AKA: TFT_DC |
| IO12 | TFT_SDO | AKA: TFT_MISO |
| IO13 | TFT_SDI | AKA: TFT_MOSI |
| IO14 | TFT_SCK | |
| IO15 | TFT_CS | |
| IO21 | TFT_BL | Also on P3 connector, for some reason |
| Pad | Use | Note |
|---|---|---|
| S1 | GND | near USB-SERIAL |
| S2 | 3.3v | for ESP32 |
| S3 | 5v | near USB-SERIAL |
| S4 | GND | for ESP32 |
| S5 | 3.3v | for TFT |
| JP0 (pad nearest USB socket) | 5v | TFT LDO |
| JP0 | 3.3v | TFT LDO |
| JP3 (pad nearest USB socket) | 5v | ESP32 LDO |
| JP3 | 3.3v | ESP32 LDO |