ROCK Pi 4 is a Rockchip RK3399 based SBC(Single Board Computer) by Radxa. It can run android or some Linux distributions. ROCK Pi 4 features a six core ARM processor, 64bit dual channel 3200Mb/s LPDDR4, up to 4K@60 HDMI, MIPI DSI, MIPI CSI, 3.5mm jack with mic, 802.11 ac WIFI, Bluetooth 5.0, USB Port, GbE LAN, 40-pin color expansion header, RTC. Also, ROCK Pi 4 supports USB PD and QC powering.
ROCK Pi 4 comes in three models, Model A and Model B has 1GB, 2GB or 4GB ram options, Model C has 4GB ram only. For detailed difference of three models, please check Specifications.
- UART: ttyS0 not usable, use ttyS2 and ttyS4
- UART2 is enabled as U-boot and Linux serial console by default. Check Rockpi4/dev/serial-console to use. Check Rockpi4/hardware/devtree_overlays to disable serial console on UART2.
- UART2 & UART4 support a wide range of baud rate. It includes but not is not limited to the following baud rates. For instance, 115200bps. 500000bps, 1500000bps and so on.
- Function marked with color orange is the default function of this pin.
- Except Pins for power supply, all pins are laid out directly to Soc RK3399.
- For pin 3, 5, 27, 28, 29 and 31, each pin is connected to the 3.0V supply through a 4.7K pull-up resistor.
- Pin 19, 21, 23, 24 are laid out directly to the pins of SPI device on board.
- Pin 7 is laid out directly to the pin of MIPI CSI on board.
- For I2C-2 and I2C-7
- We have do the test using the i2c device e2prom. We need to open the i2c device file, and then do the read or write operation.
PROCK Pi 4 has a 40-pin expansion header. Each pin is distinguished by color.
| Additional Function | Primary Function | PIN | PIN | Primary Function | Additional Function |
|---|---|---|---|---|---|
| +3.3V | 1 | 2 | +5.0V | ||
| I2C7_SDA | 3 | 4 | +5.0V | ||
| I2C7_SCL | 5 | 6 | GND | ||
| SPI2_CLK | 7 | 8 | UART2_TXD | ||
| GND | 9 | 10 | UART2_RXD | ||
| PWM0 | 11 | 12 | I2S1_SCLK | ||
| PWM1 | 13 | 14 | GND | ||
| SPDIF_TX | 15 | 16 | GPIO4_D2 | ||
| +3.3V | 17 | 18 | GPIO4_D4 | ||
| UART4_TXD | SPI1_TXD | 19 | 20 | GND | |
| UART4_RXD | SPI1_RXD | 21 | 22 | GPIO4_D5 | |
| SPI1_CLK | 23 | 24 | SPI1_CSn | ||
| GND | 25 | 26 | ADC_IN0 | ||
| I2C2_SDA | 27 | 28 | I2C2_CLK | ||
| I2C6_SCL | SPI2_TXD | 29 | 30 | GND | |
| I2C6_SDA | SPI2_RXD | 31 | 32 | SPDIF_TX | UART3_CTSn |
| SPI2_CSn | 33 | 34 | GND | ||
| I2S1_LRCK_TX | 35 | 36 | I2S1_LRCK_RX | ||
| GPIO4_D6 | 37 | 38 | I2S1_SDI | ||
| GND | 39 | 40 | I2S1_SDO |
The following links will take you to additional Rock Pi 4 resources