Pi Pin mapping
| Pin | Raspberry Pi Functions | RATT Usage | Function |
|---|---|---|---|
| 1 | +3V3 OUT | POWER | Output only |
| 2 | +5V | POWER | 5V input up to 10W recommended, NO protection |
| 3 | GPIO2/I2C1_SDA | I2C SDA | I2C bus for I/O expander and other peripherals |
| 4 | +5V | POWER | 5V input up to 10W recommended, NO protection |
| 5 | GPIO3/I2C1_SCL | I2C SCL | I2C bus for I/O expander and other peripherals |
| 6 | GND | POWER | |
| 7 | GPIO4/GPCLK0 | I/O exp /RST | Active low reset line for I/O expander |
| 8 | GPIO14/UART0_TX | RFID TX | Optional TX to RFID module (or other device) |
| 9 | GND | POWER | |
| 10 | GPIO15/UART0_RX | RFID RX | Received data from RFID module |
| 11 | GPIO17 | I2C exp /INT | Active low interrupt line for I/O expander |
| 12 | GPIO18/PWM0/SPI1_CS0/I2S_CLK | I2S CLK | Clock for I2S audio DAC |
| 13 | GPIO27/ARM_TMS | PWR_SHUTDOWN | Self-shutdown signal for battery (details TBD) |
| 14 | GND | POWER | |
| 15 | GPIO22 | ||
| 16 | GPIO23 | LCD_RESET | Reset control for LCD |
| 17 | +3V3 OUT | POWER | Output only |
| 18 | GPIO24 | LCD D/C | Data/Command control for LCD |
| 19 | GPIO10/SPI_MOSI | LCD_MOSI | Master Out Slave In (data to LCD) |
| 20 | GND | POWER | |
| 21 | GPIO9/SPI_MISO | LCD_MISO | Master In Slave Out (data from LCD) |
| 22 | GPIO25 | ||
| 23 | GPIO11/SPI_SCLK | LCD_SCLK | SPI Clock for LCD |
| 24 | GPIO8/SPI_CS0 | LCD_CS | Chip select for LCD |
| 25 | GND | POWER | |
| 26 | GPIO7/SPI_CS1 | RESERVED | SPI_CS1 |
| 27 | GPIO0/ID_SD | NC | Reserved by Pi for HAT EEPROM |
| 28 | GPIO1/ID_SC | NC | Reserved by Pi for HAT EEPROM |
| 29 | GPIO5/GPCLK1 | LCD_BL | On/Off/PWM control of LED backlight in LCD |
| 30 | GND | POWER | |
| 31 | GPIO6/GPCLK2 | ||
| 32 | GPIO12 | CHARGE_STATUS | LiPo charger status (HIGH=Charged or not present, LOW=charging) |
| 33 | GPIO13/PWM1 | ||
| 34 | GND | POWER | |
| 35 | GPIO19/PWM1/SPI1_MISO/I2S_LRCLK | I2S LRCLK | LR Clock for I2S audio DAC |
| 36 | GPIO16/SPI1_CS2 | ||
| 37 | GPIO26 | PWR_LOSS | Power loss signal (HIGH=5V_IN present, LOW implies running on battery) |
| 38 | GPIO20/SPI1_MOSI/I2S_DIN | (Reserved for I2S) | |
| 39 | GND | POWER | |
| 40 | GPIO21/SPI1_SCLK/I2S_DOUT | I2S DOUT | Data for I2S audio DAC |
| Pin | Function |
|---|---|
| P00 (4) | Application IN0 (Grove 1 Pin 1) |
| P01 (5) | Application IN1 (Grove 1 Pin 2) |
| P02 (6) | Application IN2 (Grove 2 Pin 1) |
| P03 (7) | Application IN3 (Grove 2 Pin 2) |
| P04 (8) | Application OUT0 (Grove 3 Pin 1) |
| P05 (9) | Application OUT1 (Grove 3 Pin 2) |
| P06 (10) | Application OUT2 (Grove 4 Pin 1) |
| P07 (11) | Application OUT3 (Grove 4 Pin 2) |
| P10 (13) | /BUTTON0 - Leftmost key (KEY_ESC) |
| P11 (14) | /BUTTON1 - (KEY_DOWN) |
| P12 (15) | /BUTTON2 - (KEY_UP) |
| P13 (16) | /BUTTON3 - Rightmost key (KEY_ENTER) |
| P14 (17) | /LED0 |
| P15 (18) | /LED1 |
| P16 (19) | Unused, pulled up |
| P17 (20) | Unused, pulled up |