Zero/dev/libmraa
Radxa Zero > Development Guide > Install Libmraa
Contents
Libmraa on Radxa Zero
This guide describes how to use libmraa on Radxa Zero.
Requirement
- Radxa Zero board
- The newest image in https://github.com/radxa/radxa-zero-images-released/releases
Install essential packages
Package libmraa is in the Radxa APT Focal and Buster repositories.
Uncomment file /etc/apt/sources.list.d/apt-radxa-com.list like this and save it.
For Focal
root@zero:~# cat /etc/apt/sources.list.d/apt-radxa-com.list deb http://apt.radxa.com/focal-stable/ focal main deb http://apt.radxa.com/focal-testing/ focal main
For Buster
root@zero:~# cat /etc/apt/sources.list.d/apt-radxa-com.list deb http://apt.radxa.com/buster-stable/ buster main deb http://apt.radxa.com/buster-testing/ buster main
Install essential packages:
rock@zero:~$ sudo apt-get update rock@zero:~$ sudo apt-get install -y libmraa
Install compiler:
rock@zero:~$ sudo apt install -y build-essential
Enable interface
See Radxa Zero GPIO pintout. Radxa Zero has a 40-pin colorful expansion header. Each pin is distinguished by color. mraa define is shown below: 23 GPIO:
PIN03 GPIOA_14 PIN05 GPIOA_15 PIN07 GPIOAO_3 PIN08 GPIOAO_0 PIN10 GPIOAO_1 PIN11 GPIOAO_2 PIN12 GPIOX_9 PIN13 GPIOX_11 PIN16 GPIOX_10 PIN18 GPIOX_8 PIN19 GPIOH_4 PIN21 GPIOH_5 PIN22 GPIOC_7 //Not supported gpio funtion now PIN23 GPIOH_7 PIN24 GPIOH_6 PIN27 GPIOAO_3 PIN28 GPIOAO_2 PIN32 GPIOAO_4 PIN35 GPIOAO_8 PIN36 GPIOH_8 PIN37 GPIOAO_9 PIN38 GPIOAO_10 PIN40 GPIOAO_11
3 I2C:
PIN23 I2C1_SCL PIN24 I2C1_SDA PIN13 I2C1_SCL PIN16 I2C1_SDA //these are two i2c-1, only one can be opened when using PIN3 I2C3_SDA PIN5 I2C3_SCL PIN7 I2C4_SDA PIN11 I2C4_SCL PIN27 I2C4_SDA PIN28 I2C4_SCL ///these are two i2c-4, only one can be opened when using
2 SPI: pwm_c
PIN12 SPI0RX //must disable i2c1 uart1 pwm_c PIN13 SPI0CLK PIN16 SPI0CSN PIN18 SPI0TX PIN19 SPI1TX //must disable i2c1 uart4 PIN21 SPI1RX PIN23 SPI1CLK PIN24 SPI1CSN
3 UART:
PIN8 UART0_TX PIN10 UART0_RX PIN7 UART1_RX //must disable i2c4 PIN11 UART1_TX PIN27 UART1_RX PIN28 UART1_TX PIN23 UART4_TX //must disable i2c1 spi1 PIN24 UART4_RX
2 PWM:
PIN18 PWM18 PIN40 PWM40
For those Radxa Zero system images released, the configuration file is /boot/uEnv.txt. For more details, follow this guide, Device tree overlays.
Test
Package libmraa provides some examples for testing spi, uart, i2c, gpio, etc. We way use the c files in /usr/local/share/mraa/examples/c.
And we copy them to home directory.
rock@zero:~$ cp -av /usr/local/share/mraa/examples/c /home/rock/mraa-examples
You should pay more attention to the Black Bold words when modifying configuration file /boot/uEnv.txt.
About all the overlay list is in [here].
GPIO test
Use mraa-gpio tool to test
root@rockpis:~# mraa-gpio list 01 3V3: 02 5V: 03 I2C_EE_M3_S: GPIO I2C 04 5V: 05 I2C_EE_M3_S: GPIO I2C 06 GND: 07 I2C_AO_M0_S: GPIO I2C UART 08 UART_AO_A_T: GPIO UART 09 GND: 10 UART_AO_A_R: GPIO UART 11 I2C_AO_M0_S: GPIO I2C UART 12 SPI_A_MISO: GPIO SPI 13 I2C_EE_M1_S: GPIO I2C SPI 14 GND: 15 SARADC_CH1: 16 I2C_EE_M1_S: GPIO I2C SPI 17 3V3: 18 SPI_A_MOSI,: GPIO SPI PWM 19 SPI_B_MOSI: GPIO SPI 20 GND: 21 SPI_B_MISO: GPIO SPI 22 GPIOC_7: GPIO 23 I2C_EE_M1_S: GPIO I2C SPI UART 24 UART_EE_C_R: GPIO I2C SPI UART 25 GND: 26 SARADC_CH2: 27 I2C_AO_M0_S: GPIO I2C UART 28 I2C_AO_M0_S: GPIO I2C UART 29 NC: 30 GND: 31 NC: 32 GPIOAO_4: GPIO 33 NC: 34 GND: 35 UART_AO_B_T: GPIO UART 36 GPIOH_8: GPIO 37 UART_AO_B_R: GPIO UART 38 GPIOAO_10: GPIO 39 GND: 40 PWMAO_A: GPIO PWM
root@rockpis:~# mraa-gpio set 40 1 #pin40 pull high root@rockpis:~# mraa-gpio set 40 0 #pin40 pull low
PWM test
Radxa Zero provides 2 PWM, PWM_C and PWMAO_A. It is necessary to enable then at the same time if you need PWM function.
Firstly, modify the /boot/uEnv.txt file to add the following.
rock@zero:~$ cat /boot/uEnv.txt verbosity=7 console=ttyAML0,115200 overlay_prefix=meson rootfstype=ext4 fdtfile=amlogic/meson-g12a-radxa-zero.dtb overlays=meson-g12a-uart-ao-a-on-gpioao-0-gpioao-1 meson-g12a-pwm-c-on-gpiox-8 meson-g12a-pwmao-a-on-gpioao-11 rootuuid=bbe0631f-bbed-4033-8f75-fa5930deceed initrdsize=0xf1ee3e kernelversion=5.10.69-5-amlogic-gfeede6ac474e initrdimg=initrd.img-5.10.69-5-amlogic-gfeede6ac474e kernelimg=vmlinuz-5.10.69-5-amlogic-gfeede6ac474e
Modify the macro PWM in /home/rock/mraa-examples/pwm.c as follows to test PWM_C. To test PWMAO_A, change #define PWM 18 to #define PWM 40.
/* PWM declaration */ #define PWM 18
Save and compile pwm.c
rock@zero:~/mraa-examples$ gcc -o pwm pwm.c -lmraa rock@zero:~/mraa-examples$ sudo ./pwm PWM value is 0.010015 PWM value is 0.019985 PWM value is 0.030000 PWM value is 0.040014 PWM value is 0.049984 PWM value is 0.059999
I2C test
Radxa Zero provides 3 I2C,There are I2C1 ,I2C3, I2C4. If you need the I2C function, you can turn on one or more of them.
Firstly, modify the /boot/uEnv.txt file to add the following
rock@zero:~$ cat /boot/uEnv.txt verbosity=7 console=ttyAML0,115200 overlay_prefix=meson rootfstype=ext4 fdtfile=amlogic/meson-g12a-radxa-zero.dtb overlays=meson-g12a-uart-ao-a-on-gpioao-0-gpioao-1 meson-g12a-i2c-ee-m1-gpioh-6-gpioh-7 rootuuid=bbe0631f-bbed-4033-8f75-fa5930deceed initrdsize=0xf1ee3e kernelversion=5.10.69-5-amlogic-gfeede6ac474e initrdimg=initrd.img-5.10.69-5-amlogic-gfeede6ac474e kernelimg=vmlinuz-5.10.69-5-amlogic-gfeede6ac474e
We use MPU6050 test i2c. Modify the macro MPU6050 in /home/rock/mraa-examples/i2c_mpu6050.c ,as follows to test I2C1.
/* mraa header */
#include "mraa/i2c.h"
#define I2C_BUS 0
rock@zero:~/mraa-examples$ gcc -o i2c_mpu6050 i2c_mpu6050.c -lmraa
rock@zero:~/mraa-examples$ sudo ./i2c_mpu6050
accel: x:0 y:0 z:0
gyro: x:-10 y:1 z:7
accel: x:0 y:0 z:0
gyro: x:107 y:-12 z:69
accel: x:0 y:0 z:0
gyro: x:6 y:136 z:-50
accel: x:0 y:0 z:0
gyro: x:-5 y:48 z:-103
accel: x:0 y:0 z:0
gyro: x:3 y:3 z:5
UART test
Radxa Zero provides 3 UART,There are uart0 ,uart1, uart4. If you need the uart function, you can turn on one or more of them.
Firstly, Disable console and enable uart0 for uart test.modify the /boot/uEnv.txt file to add the following
rock@zero:~$ cat /boot/uEnv.txt verbosity=7 console=ttyAML0,115200 overlay_prefix=meson rootfstype=ext4 fdtfile=amlogic/meson-g12a-radxa-zero.dtb overlays=meson-g12a-uart-ao-a-on-gpioao-0-gpioao-1 meson-g12a-uart-ao-b-on-gpioao-2-gpioao-3 console= rootuuid=bbe0631f-bbed-4033-8f75-fa5930deceed initrdsize=0xf1ee3e kernelversion=5.10.69-5-amlogic-gfeede6ac474e initrdimg=initrd.img-5.10.69-5-amlogic-gfeede6ac474e kernelimg=vmlinuz-5.10.69-5-amlogic-gfeede6ac474e
Here set console to NULL value. then reboot . use ssh connect to zero,we must have 2 windows,one is for send data,anothor is receiver by serial com.
send command follow:
rock@zero:~$ sudo mraa-uart dev 0 baud 1500000 send radxa
Another window sets the baud 1500000 and receives the data
radxa
receive command follow:
rock@zero:~$ sudo mraa-uart dev 0 baud 1500000 recv 1000 radxa
SPI test
Firstly, modify the /boot/uEnv.txt file.
rock@zero:~$ cat /boot/uEnv.txt verbosity=7 console=ttyAML0,115200 overlay_prefix=meson rootfstype=ext4 fdtfile=amlogic/meson-g12a-radxa-zero.dtb overlays=meson-g12a-uart-ao-a-on-gpioao-0-gpioao-1 meson-g12a-spi-spidev param_spidev_spi_bus=0 param_spidev_max_freq=10000000 rootuuid=bbe0631f-bbed-4033-8f75-fa5930deceed initrdsize=0xf1ee3e kernelversion=5.10.69-5-amlogic-gfeede6ac474e initrdimg=initrd.img-5.10.69-5-amlogic-gfeede6ac474e kernelimg=vmlinuz-5.10.69-5-amlogic-gfeede6ac474e
then execute command, sync, followed by reboot.
Create file test-spi.c and add the following contents.
rock@zero:~/mraa-examples$ cat test-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 10000000
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;
}
j = 10;
while(j) {
j--;
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;
}
rock@zero:~/mraa-examples$ gcc -o test-spi test-spi.c -lmraa
Then short pin12 and pin18 and run test-spi
rock@zero:~/mraa-examples$ sudo ./test-spi 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa MRAA: SUCCESS
Development
More introduction of libmraa can look at libmraa official website.
Troubleshooting
- Refer Troubleshooting page
- Post your issue on the forum: https://forum.radxa.com/c/zero