RockpiE/dev/libmraa
ROCK Pi E > Development > libmraa
Contents
Libmraa-rockpie
Install libmraa
Modify your /etc/apt/sources.list.d/apt-radxa-com.list as follow :
#deb http://apt.radxa.com/buster-stable/ buster main deb http://apt.radxa.com/buster-testing/ buster main
Get the pub key :
wget -O - apt.radxa.com/buster-testing/public.key | sudo apt-key add -
Update APT package information :
sudo apt-get update
Install libmraa :
sudo apt-get install libmraa-rockpie
Enable interface
See ROCK Pi E GPIO pintout. ROCK Pi E has one 40-pin expansion header. Each pin is distinguished by color.
Hardware V1.0/V1.1
25 GPIO:
PIN3 GPIO2_A4 PIN5 GPIO2_A5 PIN7 GPIO3_A4 PIN8 GPIO2_A0 PIN10 GPIO2_A1 PIN11 GPIO3_A0 PIN12 GPIO2_D2 PIN13 GPIO3_B0 PIN15 GPIO3_A2 PIN19 GPIO0_D3 PIN21 GPIO2_C3 PIN22 GPIO2_B4 PIN23 GPIO1_D4 PIN24 GPIO2_A3 PIN26 GPIO2_C7 PIN27 GPIO3_A1 PIN28 GPIO2_C1 PIN29 GPIO2_C0 PIN31 GPIO2_B7 PIN32 GPIO3_A6 PIN33 GPIO2_C2 PIN36 GPIO2_C5 PIN37 GPIO2_A2 PIN38 GPIO2_C4 PIN40 GPIO2_C6
I2C: x1, I2C1
PIN3 I2C1_SDA PIN5 I2C1_SCL
SPI: x1, SPI0(Pin#11/13/15/27)
PIN11 SPI_CLK_M2 PIN13 SPI_CSN0_M2 PIN15 SPI_RXD_M2 PIN27 SPI_TXD_M2
UART: x1, UART1 and UART2
PIN7 UART1_TX PIN32 UART1_RX PIN8 UART2_TX_M1 PIN10 UART2_RX_M1
ADC_IN1: x1, ADC_IN1
PIN35 ADC_IN1
Modify /boot/uEnv.txt to enable uart1 and spi0 for test,as follow :
verbosity=7 fdtfile=rockchip/rk3328-rock-pi-e.dtb console=ttyS2,1500000n8 overlays=rk3328-uart2 rk3328-spi-spidev rk3328-uart1 param_spidev_spi_bus=0 param_spidev_spi_cs=0 param_spidev_max_freq=10000000 initrdsize=0x655f2d kernelversion=4.4.194-12-rockchip-g615ae7431150 initrdimg=initrd.img-4.4.194-12-rockchip-g615ae7431150 kernelimg=vmlinuz-4.4.194-12-rockchip-g615ae7431150 rootuuid=6bdd02ee-ae60-404d-99c9-913f3f1bffb1
then reboot
Test
test gpio
Use mraa-gpio to test
rock@rockpie:~$ mraa-gpio list 01 3V3: 02 5V: 03 SDA1: GPIO I2C 04 5V: 05 SCL1: GPIO I2C 06 GND: 07 TXD1: GPIO UART 08 TXD2: GPIO UART 09 GND: 10 RXD2: GPIO UART 11 SPI_CLK_M2: GPIO SPI 12 GPIO2_D2: GPIO 13 SPI_CSN0_M2: GPIO SPI 14 GND: 15 SPI_RXD_M2: GPIO SPI 16 USB20DM: 17 3V3: 18 USB20DP: 19 GPIO0_D3: GPIO 20 GND: 21 GPIO2_C3: GPIO 22 GPIO2_B4: GPIO 23 GPIO1_D4: GPIO 24 GPIO2_A3: GPIO 25 GND: 26 GPIO2_C7: 27 SPI_TXD_M2: GPIO SPI 28 GPIO2_C1: GPIO 29 GPIO2_C0: GPIO 30 GND: 31 GPIO2_B7: GPIO 32 UART1_RX: GPIO UART 33 GPIO2_C2: GPIO 34 GND: 35 ADC_IN1: AIO 36 GPIO2_C5: GPIO 37 GPIO2_A2: GPIO 38 GPIO2_C4: GPIO 39 GND: 40 GPIO2_C6: GPIO rock@rockpie:~$ rock@rockpie:~$ sudo mraa-gpio set 23 1 //pin40 pull high rock@rockpie:~$ sudo mraa-gpio set 23 0 //pin40 pull low
test i2c
Use mraa-i2c to test, we must have a i2c slave device , for example, we use I2C EEPROM:
rock@rockpie:~$ mraa-i2c list Bus 0: id=01 type=linux default rock@rockpie:~$ sudo mraa-i2c detect 0 00: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- 18 -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: 50 51 52 53 54 55 56 57 -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- rock@rockpie:~$ sudo mraa-i2c set 0 0x50 0x10 0x55 Device 50, Register = 10, Value = 55 rock@rockpie:~$ sudo mraa-i2c get 0 0x50 0x10 Register 0X10 = 0X55 rock@rockpie:~$
test spi
fristly, modify /boot/uEnv.txt to enable the spi0, The changes are as follows :
rock@rockpie:~$ cat /boot/uEnv.txt verbosity=7 fdtfile=rockchip/rk3328-rock-pi-e.dtb console=ttyS2,1500000n8 overlays=rk3328-uart2 rk3328-spi-spidev param_spidev_spi_bus=0 param_spidev_spi_cs=0 param_spidev_max_freq=10000000 initrdsize=0x655f2d kernelversion=4.4.194-12-rockchip-g615ae7431150 initrdimg=initrd.img-4.4.194-12-rockchip-g615ae7431150 kernelimg=vmlinuz-4.4.194-12-rockchip-g615ae7431150 rootuuid=6bdd02ee-ae60-404d-99c9-913f3f1bffb1 rock@rockpie:~$
After modification, you need to reboot
use c to test spi,compile spi.c.
root@rockpie:~# cat spi.c
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
/* mraa header */
#include "mraa/spi.h"
/* SPI declaration */
#define SPI_BUS 0
/* SPI frequency in Hz */
#define SPI_FREQ 400000
int
main(int argc, char** argv)
{
mraa_result_t status = MRAA_SUCCESS;
mraa_spi_context spi;
int i, j;
/* initialize mraa for the platform (not needed most of the times) */
mraa_init();
//! [Interesting]
/* initialize SPI bus */
spi = mraa_spi_init(SPI_BUS);
if (spi == NULL) {
fprintf(stderr, "Failed to initialize SPI\n");
mraa_deinit();
return EXIT_FAILURE;
}
/* set SPI frequency */
status = mraa_spi_frequency(spi, SPI_FREQ);
if (status != MRAA_SUCCESS)
goto err_exit;
/* set big endian mode */
status = mraa_spi_lsbmode(spi, 0);
if (status != MRAA_SUCCESS) {
goto err_exit;
}
while(1) {
printf("0x%x\n",mraa_spi_write(spi, 0xaa));
}
err_exit:
mraa_result_print(status);
/* stop spi */
mraa_spi_stop(spi);
/* deinitialize mraa for the platform (not needed most of the times) */
mraa_deinit();
return EXIT_FAILURE;
}
root@rockpie:~# gcc spi.c -lmraa
then short pin15 and pin27 and run a.out
root@rockpie:~# ./a.out 0xaa 0xaa ......
test Uart
Enable Uart1 for uart test, The changes are as follows :
rock@rockpie:~$ cat /boot/uEnv.txt verbosity=7 fdtfile=rockchip/rk3328-rock-pi-e.dtb console=ttyS2,1500000n8 overlays=rk3328-uart2 rk3328-uart1 initrdsize=0x655f2d kernelversion=4.4.194-12-rockchip-g615ae7431150 initrdimg=initrd.img-4.4.194-12-rockchip-g615ae7431150 kernelimg=vmlinuz-4.4.194-12-rockchip-g615ae7431150 rootuuid=6bdd02ee-ae60-404d-99c9-913f3f1bffb1 rock@rockpie:~$
then reboot and short pin7 and pin32. use ssh connect to rockpie,we must have 2 windows,one is for send data,anothor is for receive.
send command follow:
sudo mraa-uart dev 0 baud 1500000 send data
receive command follow:
sudo mraa-uart dev 0 baud 1500000 recv 1000
the receive window will show the data
test adc
Firstly, short pin23 and pin35, Compile mraa example file to test, as follow:
rock@rockpie:~$ cp /usr/local/share/mraa . -r rock@rockpie:~$ cd mraa/examples/ rock@rockpie:~/mraa/examples$ ls CMakeLists.txt c c++ python rock@rockpie:~/mraa/examples$ mkdir build rock@rockpie:~/mraa/examples$ cd build rock@rockpie:~/mraa/examples/build$ sudo apt-get install cmake rock@rockpie:~/mraa/examples/build$ sudo apt-get install g++ rock@rockpie:~/mraa/examples/build$ cmake .. rock@rockpie:~/mraa/examples/build$ cd c; make rock@rockpie:~/mraa/examples/build/c$ sudo su [sudo] password for rock: #password:rock root@rockpie:/home/rock/mraa/examples/build/c# ./gpio & [1] 1250 root@rockpie:/home/rock/mraa/examples/build/c# ./aio ADC A0 read 3FF - 1023 ADC A0 read float - 1.00000 ADC A0 read 3FF - 1023 ADC A0 read float - 1.00000 ... ADC A0 read 0 - 0 ADC A0 read float - 0.00000 ADC A0 read 0 - 0 ADC A0 read float - 0.00000
More examples
More examples (including examples written in python) can be found at:
/usr/local/share/mraa/examples/