PCBCUPID Cypher Board-Support Library

An Arduino-compatible board-support library for the PCBCUPID Cypher development board (CYPHER V-1.0), built around the ESP32-S3-MINI-1. Provides a simple, unified API for all onboard peripherals.

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Overview

The PCBCUPID Cypher library wraps the most common Cypher board peripherals into a single class:

• 0.96" TFT Display (ER-TFT0.96-4, ST7735 compatible) — SPI
• MicroSD Card — SDIO 4-bit & SPI fallback
• Real-Time Clock (PCF8563T) — I2C
• RGB LED — common-anode, active-low GPIO control
• Boot Button — GPIO0 with pull-up

Designed for ESP32 (tested on Cypher V-1.0), this library lets you focus on your application instead of memorising pin numbers.

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Key Features

Simple API

• Single begin() call initialises the entire board
• beginLight() for power-sensitive applications (I2C + RTC only)
• setRGBLed(CYPHER_COLOR_GREEN) for quick LED control

Timekeeping

• Read/write date & time from the onboard PCF8563T RTC
• BCD conversion handled internally
• Voltage-low detection and reporting

Storage

• SDIO 4-bit mode for high-speed MicroSD access
• SPI fallback mode for compatibility
• Uses standard SD_MMC / SD Arduino libraries

Display Ready

• Configures all TFT GPIOs and performs hardware reset
• Ready to use with Adafruit_ST7735 / Adafruit_GFX
• Pin mapping exported as preprocessor constants

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Hardware Support

Supported Board:

• PCBCUPID Cypher V-1.0 (ESP32-S3-MINI-1)

Onboard Peripherals:

Peripheral	Interface	Chip / Part
TFT Display	SPI	ER-TFT0.96-4 (ST7735)
MicroSD Card	SDIO / SPI	—
Real-Time Clock	I2C (0x51)	PCF8563T
RGB LED	GPIO	Common-anode LED
Status LED	GPIO	Red 0603 LED

Compatible Platforms:

• ESP32-S3 (all variants)

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Pin Reference

Function	GPIO	Notes
I2C SDA	4	RTC & expansion
I2C SCL	5	RTC & expansion
TFT RST	8	Display reset
TFT DC	9	Data / Command
TFT CS	10	Chip select
TFT MOSI	11	SPI data
TFT SCLK	12	SPI clock
SD CMD	35	SDIO / SPI CS
SD CLK	36	SDIO / SPI SCK
SD D0	37	SDIO data 0 / SPI MISO
SD D1	38	SDIO data 1
SD D2	39	SDIO data 2
SD D3	40	SDIO data 3
RGB Red	1	Common-anode (LOW = ON)
RGB Green	2	Common-anode (LOW = ON)
RGB Blue	3	Common-anode (LOW = ON)
Status LED	6	Active-low
Boot Button	0	Pull-up, LOW = pressed
Reset Button	EN	Hard reset
USB D+	20	Native USB
USB D-	19	Native USB
U0 TXD	43	Serial console
U0 RXD	44	Serial console
U1 TXD	17	Aux UART
U1 RXD	18	Aux UART

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Quick Start

#include <PCBCUPID_Cypher.h>
#include <Adafruit_ST7789.h>   // ST7735 is compatible

TwoWire I2Cbus(0);
PCBCUPID_Cypher cypher(I2Cbus);
Adafruit_ST7789 tft(CYPHER_TFT_CS, CYPHER_TFT_DC, CYPHER_TFT_RST);

void setup() {
    Serial.begin(115200);

    // 1. Initialise the board
    cypher.begin();

    // 2. Start the display
    cypher.beginTFT();
    tft.init(CYPHER_TFT_HEIGHT, CYPHER_TFT_WIDTH);
    tft.setRotation(1);
    tft.fillScreen(ST77XX_BLACK);

    // 3. Light up the RGB LED green
    cypher.setRGBLed(CYPHER_COLOR_GREEN);

    // 4. Read the RTC
    uint16_t year;
    uint8_t month, day, wday, hour, minute, second;
    if (cypher.readRTC(year, month, day, wday, hour, minute, second)) {
        Serial.printf("RTC: %04u-%02u-%02u %02u:%02u:%02u\n",
                      year, month, day, hour, minute, second);
    }
}

void loop() {
    // Toggle status LED each second
    cypher.toggleStatusLed();
    delay(1000);
}

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API Reference

Initialisation

bool begin();          // Full board init (I2C, RTC, GPIOs, LEDs)
bool beginLight();     // I2C + RTC only (low-power)

Board Info

CypherInfo getInfo();  // Returns board name, version, MCU

RGB LED

void setRGBLed(CypherLedColor color);   // Preset colours
void setRGBLedRaw(uint8_t r, uint8_t g, uint8_t b); // 0=ON, 255=OFF (PWM)

Preset colours: CYPHER_COLOR_OFF, CYPHER_COLOR_RED, CYPHER_COLOR_GREEN, CYPHER_COLOR_BLUE, CYPHER_COLOR_YELLOW, CYPHER_COLOR_CYAN, CYPHER_COLOR_MAGENTA, CYPHER_COLOR_WHITE

Status LED

void setStatusLed(bool on);
void toggleStatusLed();

Buttons

bool isBootPressed();  // true when SW2 held down

RTC

bool readRTC(uint16_t &year, uint8_t &month, uint8_t &day,
             uint8_t &weekday, uint8_t &hour,
             uint8_t &minute, uint8_t &second);

bool setRTC(uint16_t year, uint8_t month, uint8_t day,
            uint8_t weekday, uint8_t hour,
            uint8_t minute, uint8_t second);

Storage

bool beginSD();                              // SDIO 4-bit mode
bool beginSD_SPI(uint8_t csPin = CYPHER_SD_CMD); // SPI fallback

Display

bool beginTFT();   // Configure GPIOs + hardware reset

Utilities

void scanI2C();    // Scan I2C bus, print results to Serial
TwoWire &getWire(); // Access the underlying I2C instance

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Examples

Included examples demonstrate:

• basic — Full board demo: RTC read, RGB LED cycling, button monitoring, SD card mount
• display_test — TFT initialisation with ST7735 + GFX drawing
• sd_card — SD card initialisation in SDIO and SPI modes with file listing
• sd_mmc — SD_MMC + USB Mass Storage: exposes the SD card as a USB drive

Examples are located in the examples/ directory of the library.

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Dependencies

• Arduino-ESP32 core (v2.0+)
• Wire (built-in)
• SPI (built-in)
• SD_MMC (built-in, for SDIO)
• Adafruit_ST7735 + Adafruit_GFX (optional, for display)

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Documentation & Resources

• ESP32-S3-MINI-1 Datasheet: Espressif
• PCF8563 Datasheet: NXP
• ST7735 Datasheet: Sitronix
• Community Support: PCBCUPID Forum

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Credits & Attribution

Developed and maintained by PCBCUPID, based on the Cypher V-1.0 board design.

Original Author:

• Abhishek N — @PCBCUPID
• Version: 1.0.0
• License: MIT License (refer to the LICENSE file for terms)

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Contributing

We welcome contributions! Please refer to the Contributing Guidelines before submitting changes.

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License

This library is licensed under the MIT License. See the LICENSE file for full details.

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Made with 🔧 by PCBCUPID

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