Rockpi4/android-mraa

GPIO number	Function2	Function1	GPIO	Pin#	Pin#	GPIO	Function1	Function2	GPIO number
		+3.3V		1	2		+5.0V
71		I2C7_SDA	GPIO2_A7(X)	3	4		+5.0V
72		I2C7_SCL	GPIO2_B0(X)	5	6		GND
75		SPI2_CLK	GPIO2_B3(X)	7	8	GPIO4_C4(X)	UART2_TXD		148
		GND		9	10	GPIO4_C3(X)	UART2_RXD		147
146		PWM0	GPIO4_C2(X)	11	12	GPIO4_A3	I2S1_SCLK		131
150		PWM1	GPIO4_C6(X)	13	14		GND
149		SPDIF_TX	GPIO4_C5	15	16	GPIO4_D2			154
		+3.3V		17	18	GPIO4_D4			156
40	UART4_TXD	SPI1_TXD(X)	GPIO1_B0(X)	19	20		GND
39	UART4_RXD	SPI1_RXD(X)	GPIO1_A7(X)	21	22	GPIO4_D5			157
41		SPI1_CLK(X)	GPIO1_B1	23	24	GPIO1_B2	SPI1_CSn(X)		42
		GND		25	26		ADC_IN0
64		I2C2_SDA	GPIO2_A0(X)	27	28	GPIO2_A1(X)	I2C2_CLK		65
74	I2C6_SCL(X)	SPI2_TXD	GPIO2_B2(X)	29	30		GND
73	I2C6_SDA(X)	SPI2_RXD	GPIO2_B1(X)	31	32	GPIO3_C0	SPDIF_TX	UART3_CTSn	112
76		SPI2_CSn	GPIO2_B4(X)	33	34		GND
133		I2S1_LRCK_TX	GPIO4_A5	35	36	GPIO4_A4	I2S1_LRCK_RX		132
158			GPIO4_D6	37	38	GPIO4_A6	I2S1_SDI		134
		GND		39	40	GPIO4_A7	I2S1_SDO		135

Class

class	constructor	constructor2	class	constructor	constructor2
Aio	Aio (int pin_index)	NA	Gpio	Gpio(int pin_index)	NA
I2c	I2c (int i2c_index)	NA	Pwm	Pwm (int pin_index)	NA
Spi	Spi (int spi_index)	NA	Uart	Uart(int uart_index)	NA

Index Class

Field	Index Value	Hardware I2c Number	Field	Index Value	Hardware Spi Number
ROCK_PI_4_I2C2	0	i2c2	ROCK_PI_4_SPI1	0	spi1
ROCK_PI_4_I2C6	1	i2c6	ROCK_PI_4_SPI2	1	spi2
ROCK_PI_4_I2C7	2	i2c7

RockPI4Uart	Field	Index Value	Hardware Uart Number
	ROCK_PI_4_UART2	0	uart2
	ROCK_PI_4_UART4	1	uart4

Gpio

Methods	Parameter	Description	Return
dir(Dir dir)	Dir	Set input/output	Result
readDir()	void	Read input/output dir	Dir
mode(Mode mode)	Mode	Set STRONG/PULLUP/PULLDOWN/HIZ	Result
read()	void	Set input and read gpio value	0/1
write(int v)	0/1	Set output value	Result
unexport()	void	Unexport gpio in /dev/class/gpio	Result

Aio

Methods	Parameter	Description	Return
read()	void	Read value. Default will shift the raw value up/down to a 10 bit.	long
readFloat()	void	Read value and return it as a normalized float.	0.0 - 1.0
setBit(int b)	int	Set the bit value which will shift the raw reading from the ADC to.	Result
getBit()	void	Gets the bit value mraa is shifting the analog read to.	int

I2C

Methods	Parameter	Description	Return
address(short a)	0x00-0xFF	Set i2c address	Result
readByte()	void	Read a byte data form i2c	short
writeByte(short b)	Mode	Write a byte data to i2c	Result
read(byte[] buf)	byte[]	Read a byte[] data form i2c	read size
write(byte[] buf)	byte[]	Write a byte[] data to i2c	Result
readReg(short a)	0x00-0xFF	Read a byte data form i2c addr	short
writeReg(short a, short d)	0x00-0xFF, 0x00-0xFF	Write a byte data to i2c addr	Result
readWordReg(short a)	0x00-0xFF	Read a byte[2] data form i2c addr	int
writeWordReg(short a, int d)	0x00-0xFF, 0x0000-0xFFFF	Write a byte[2] data to i2c addr	Result
readBytesReg(short a, byte[] b)	0x00-0xFF, byte[]	Read a byte[] data form i2c addr	int

Pwm

Methods	Parameter	Description	Return
period(float s)	0.0001 - 2.147483	Set pwm period	Result
period_ms(int m)	1 - 2147	Set pwm period	Result
period_us(int u)	1 - 2147483	Set pwm period	Result
pulsewidth(float s)	0.0001 - 2.147483	Set pwm duty	Result
pulsewidth_ms(int m)	1 - 2147	Set pwm duty	Result
pulsewidth_us(int u)	1 - 2147483	Set pwm duty	Result
max_period()	void	Get pwm max period	int(us)
min_period()	void	Get pwm min period	int(us)
read()	void	Get pwm period/duty	0.0 - 1.0
write(float p)	0.0 - 1.0	Set pwm period/duty percentage	Result
enable(boolean e)	true/false	dis/enable pwm	Result
unexport()	void	Unexport pwm in /dev/class/pwm	Result

SPI

Methods	Parameter	Description	Return
defaultConfig()	void	Set mraa default config (mode0,lsb=0,bits=8)	Result
mode(Spi_Mode m)	void	Set spi mode	Result
frequency(int f)	int	Set spi frequency max=48000000	Result
lsbmode(boolean l)	true/false	Set spi lsmode	Result
bitPerWord(long b)	8/16	Set spi bit_pre_word	Result
writeByte(short a)	0x00-0xFF	Write a byte data to spi	int(recv data)
writeWord(int a)	0x0000-0xFFFF	Write a byte[2] data to spi	int(recv data)
write(byte[] b)	byte[]	Write a byte[] data to spi	byte[](recv data)

UART

Methods	Parameter	Description	Return
defaultConfig()	void	Set mraa default config (9600 8N1, no echo or special character)	Result
setBaudRate(long b)	long	Set uart baudrate max=150000000	Result
setMode(int bytesize, UartParity parity, int stopbits)	int	Set the transfer mode	Result
setFlowcontrol(boolean xonxoff, boolean rtscts)	true/false	Set the flowcontrol	Result
setTimeout(int read, int write, int interchar)	-1 - int_max	Set the timeout for read and write operations	Result
setNonBlocking(boolean b)	true/false	Set the blocking state for write operations	Result
sendBreak(int b)	0 - max_int	Send a break to the device.	Result
flush()	void	Flush the outbound data.	Result
dataAvailable()	void	Check to see if data is available on the device for reading, return immediately	boolean
dataAvailable(long timeout)	1 - int_max	Check to see if data is available on the device for reading and time out	boolean
readStr(int length)	1 - int_max	Read bytes from the device into a String object	String
writeStr(String s)	1 - int_max	Write bytes in String object to a device	int
read(byte[] data)	1 - int_max	Check to see if data is available on the device for reading and time out	int(read size)
wrtie(byte[] data)	1 - int_max	Check to see if data is available on the device for reading and time out	int(write size)

Example

Gpio


   import mraa.*;
   
   Gpio gpio40 = new Gpio(RockPI4.ROCK_PI_4_PIN40.swigValue());
   gpio40.dir(Dir.DIR_OUT);
   gpio40.write(1);
   // do sth
   // if you want
   gpio40.unexport();

Spi


   import mraa.*;
   
   Spi spi = new Spi(RockPI4SPI.ROCK_PI_4_SPI1.swigValue());
   byte[] recv = spi.write(new byte[]{0x11, 0x22});
   Log.d(TAG, String.format("onCreate: recv[0]=0x%x, recv[1]=0x%x", recv[0], recv[1]));

Pwm


   import mraa.*;
   
   Pwm pwm = new Pwm(RockPI4.ROCK_PI_4_PIN11.swigValue());
   pwm.period_us(20000);
   pwm.write((float) 0.5);
   pwm.enable(true);
   // do sth
   .....
   
   pwm.enable(false);
   pwm.unexport();

Aio


   import mraa.*;
   
   Aio aio = new Aio(0);
   Log.d(TAG, "aio0: " + aio.read());

I2c


   import mraa.*;
   
   I2c i2c = new I2c(RockPI4I2C.ROCK_PI_4_I2C2.swigValue());
   i2c.address((short) 0x50);
   i2c.writeReg((short)0x01, (short) 0x57);
   try {
       Thread.sleep(1000);
   } catch (InterruptedException e) {
       e.printStackTrace();
   }
   i2c.address((short) 0x50);
   Log.d(TAG, "i2c2 read: 0x" + Integer.toHexString(i2c.readReg((short)0x01)));

Uart


   import mraa.*;
   
   Uart uart = new Uart(RockPI4Uart.ROCK_PI_4_UART4.swigValue());
   uart.defaultConfig();
   uart.setBaudRate(115200);
   uart.writeStr("radxa");
   String read = uart.readStr(6);
   Log.d(TAG, "uart4 read: " + read);

Rockpi4/android-mraa

Contents

Rock PI 4 Android Mraa API

Default IO Map

Class

Index Class

Gpio

Aio

I2C

Pwm

SPI

UART

Example