RockpiS/dev/libmraa
ROCK Pi S > Development > Install Libmraa
Contents
Libmraa on ROCK Pi S
This guide describes how to use libmraa on ROCK Pi S.
Install essential packages
Package libmraa is in the Radxa APT bionic-testing and buster-testing repositories.
Execute the following commands to add Radxa APT
rock@rockpis:~$ export DISTRO=bionic-testing # for Bionic
or
rock@rockpis:~$ export DISTRO=buster-testing # for Buster rock@rockpis:~$ echo "deb http://apt.radxa.com/$DISTRO/ ${DISTRO%-*} main" | sudo tee -a /etc/apt/sources.list.d/apt-radxa-com.list
Get the pub key
rock@rockpis:~$ wget -O - apt.radxa.com/buster-testing/public.key | sudo apt-key add -
Install essential packages:
rock@rockpis:~$ sudo apt-get update rock@rockpis:~$ sudo apt-get install -y rockchip-overlay rockpis-dtbo libmraa # libmraa version: >=0.4 rock@rockpis:~$ sudo apt-get install -y linux-4.4-rockpis-latest # ROCK Pi S kernel version: >= 4.4.143-47
Enable interface
See ROCK Pi S GPIO pintout. ROCK Pi S has a 26-pin colorful expansion header. Each pin is distinguished by color. mraa define is shown below:
Hardware V12
16 GPIO:
PIN03 GPIO2_A2 PIN05 GPIO2_B0 PIN07 GPIO2_B3 PIN09 GPIO4_C4 PIN11 GPIO4_C2 PIN12 GPIO4_A3 PIN13 GPIO4_C6 PIN15 GPIO4_C5 PIN16 GPIO4_D2 PIN18 GPIO4_D4 PIN19 GPIO1_B0 PIN21 GPIO1_A7 PIN22 GPIO4_D5 PIN23 GPIO1_B1 PIN24 GPIO1_B2 PIN26 GPIO1_B2
3 I2C:
PIN23 I2C0_SDA PIN24 I2C0_SCL PIN3 I2C1_SCL PIN5 I2C1_SDA PIN13 I2C3_SDA PIN15 I2C3_SCL
1 SPI:
PIN19 SPI2TX //must disable i2c0 PIN21 SPI2RX //must disable i2c0 PIN23 SPI2CLK PIN24 SPI2CSN
3 UART:
PIN8 UART0_TX PIN10 UART0_RX PIN23 UART1_TX PIN24 UART1_RX PIN19 UART2_RX PIN21 UART2_TX
2 PWM:
PIN11 PWM2 PIN13 PWM3
1 ADC:
PIN26 ADC_IN0 //the measure voltage must lower than 1.8v
For those ROCK Pi S system images released after March 1st, 2020, to enable pwm2,pwm3,uart1,uart2,i2c0,i2c1,i2c3 and so overlays=, need to follow Device tree overlays.
For those ROCK Pi S system images released before March 1st, 2020, modify /boot/uEnv.txt to enable pwm2,pwm3,uart1,uart2,i2c0,i2c1,i2c3 for test.
rock@rockpis:~$ cat /boot/uEnv.txt verbosity=7 overlay_prefix=rockchip rootfstype=ext4 fdtfile=rockchip/rk3308-rock-pi-s.dtb overlays=rk3308-console-on-uart0 rk3308-i2c0 rk3308-i2c1 rk3308-i2c3 rootuuid=37055840-4ec4-444f-979b-9e47ee4bd848 initrdsize=0x64d1d4 kernelversion=4.4.143-47-rockchip-g495ff574976c initrdimg=initrd.img-4.4.143-47-rockchip-g495ff574976c kernelimg=vmlinuz-4.4.143-47-rockchip-g495ff574976c
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@rockpis:~/mraa-examples$ 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.
test gpio
Use mraa-gpio tool to test
root@rockpis:~# mraa-gpio list 01 3V3: 02 5V: 03 I2C_SDA: GPIO I2C 04 5V: 05 I2C_SCL: GPIO I2C 06 GND: 07 I2S0_8CH_MC: GPIO 08 UART0_TX: GPIO UART 09 GND: 10 UART0_RX: GPIO UART 11 PWM2,I2C3_S: GPIO I2C PWM 12 I2S0_8CH_SC: GPIO 13 PWM3,I2C3_S: GPIO I2C PWM 14 GND: 15 SPDIF_TX: GPIO 16 I2S0_8CH_SD: GPIO 17 3V3: 18 I2S0_8CH_SD: GPIO 19 UART1_RTSN,: GPIO SPI UART 20 GND: 21 UART1_CTSN,: GPIO SPI UART 22 I2S0_8CH_LR: GPIO 23 UART1_RX,I2: GPIO I2C SPI UART 24 UART1_TX,I2: GPIO I2C SPI UART 25 GND: 26 ADC_IN0: AIO root@rockpis:~# mraa-gpio set 15 1 #pin15 pull high root@rockpis:~# mraa-gpio set 15 0 #pin15 pull high
PWM test
ROCK Pi S V1.2 provides 2 PWM, PWM2 and PWM3. It is necessary to enable PWM1, PWM2 and PWM3 at the same time if you need PWM function.
Firstly, modify the /boot/uEnv.txt file to add the following
root@rockpis:~# cat /boot/uEnv.txt verbosity=7 overlay_prefix=rockchip rootfstype=ext4 fdtfile=rockchip/rk3308-rock-pi-s.dtb overlays=rk3308-console-on-uart0 rk3308-pwm1 rk3308-pwm2 rk3308-pwm3 rootuuid=37055840-4ec4-444f-979b-9e47ee4bd848 initrdsize=0x64d1d4 kernelversion=4.4.143-47-rockchip-g495ff574976c initrdimg=initrd.img-4.4.143-47-rockchip-g495ff574976c kernelimg=vmlinuz-4.4.143-47-rockchip-g495ff574976c
Modify the macro PWM in /home/rock/mraa-examples/pwm.c as follows to test PWM2. To test PWM3, change #define PWM 11 to #define PWM 13.
/* PWM declaration */ #define PWM 11
Save and compile pwm.c
rock@rockpis:~/mraa-examples$ gcc -o pwm pwm.c -lmraa rock@rockpis:~/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
ROCK Pi S V1.2 provides 3 I2C,There are I2C0 ,I2C1, I2C3. 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
root@rockpis:~# cat /boot/uEnv.txt verbosity=7 overlay_prefix=rockchip rootfstype=ext4 fdtfile=rockchip/rk3308-rock-pi-s.dtb overlays=rk3308-console-on-uart0 rk3308-i2c0 rk3308-i2c1 rk3308-i2c3 rootuuid=37055840-4ec4-444f-979b-9e47ee4bd848 initrdsize=0x64d1d4 kernelversion=4.4.143-47-rockchip-g495ff574976c initrdimg=initrd.img-4.4.143-47-rockchip-g495ff574976c kernelimg=vmlinuz-4.4.143-47-rockchip-g495ff574976c
We use MPU6050 tets i2c. Modify the macro MPU6050 in /home/rock/mraa-examples/i2c_mpu6050.c ,as follows to test I2C0. To test I2C1 and I2C3, change #define I2C_BUS 0 to #define I2C_BUS 1 or#define I2C_BUS 3 .
/* mraa header */ #include "mraa/i2c.h" #define I2C_BUS 0
Save and compile pwm.c
rock@rockpis:~/mraa-examples$ gcc -o i2c_mpu6050 i2c_mpu6050.c -lmraa
rock@rockpis:~/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
ROCK Pi S V1.2 provides 3 UART,There are uart0 ,uart1, uart2. If you need the uatr 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
root@rockpis:~# cat /boot/uEnv.txt verbosity=7 overlay_prefix=rockchip rootfstype=ext4 fdtfile=rockchip/rk3308-rock-pi-s.dtb overlays=rk3308-uart0 rk3308-uart1 rk3308-uart2 console= rootuuid=c3800af9-fa58-4fb3-bb56-e52fd04837ba initrdsize=0x5c96c3 kernelversion=4.4.143-47-rockchip-g495ff574976c initrdimg=initrd.img-4.4.143-47-rockchip-g495ff574976c kernelimg=vmlinuz-4.4.143-47-rockchip-g495ff574976c
then reboot . use ssh connect to rockpis,we must have 2 windows,one is for send data,anothor is for receive.
send command follow:
rock@rockpis:~$ sudo mraa-uart dev 0 baud 1500000 send radxa
Another window sets the baud 1500000 and receives the data
radxa
receive command follow:
rock@rockpis:~$ sudo mraa-uart dev 0 baud 1500000 recv 1000 radxa
SPI test
Firstly, modify the /boot/uEnv.txt file.
root@rockpis:~# cat /boot/uEnv.txt verbosity=7 overlay_prefix=rockchip rootfstype=ext4 fdtfile=rockchip/rk3308-rock-pi-s.dtb overlays=rk3308-console-on-uart0 rk3308-spi-spidev param_spidev_spi_bus=2 rootuuid=37055840-4ec4-444f-979b-9e47ee4bd848 initrdsize=0x64d1d4 kernelversion=4.4.143-47-rockchip-g495ff574976c initrdimg=initrd.img-4.4.143-47-rockchip-g495ff574976c kernelimg=vmlinuz-4.4.143-47-rockchip-g495ff574976c
then execute command, sync, followed by reboot.
Create file test-spi.c and add the following contents.
rock@rockpis:~/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 2
/* 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@rockpis:~/mraa-examples$ gcc -o test-spi test-spi.c -lmraa
Then short pin19 and pin21 and run test-spi
rock@rockpis:~/mraa-examples$ sudo ./test-spi 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa MRAA: SUCCESS
ADC test
connect signal you want to measure, and then compile mraa example c file, aio.c, to test.
rock@rockpis:~/mraa-examples$ gcc aio aio.c -lmraa rock@rockpis:~/mraa-examples$ sudo ./aio ADC A0 read 1A5 - 421 ADC A0 read float - 0.41153 ADC A0 read 1A5 - 421 ADC A0 read float - 0.41153 ADC A0 read 1A5 - 421 ADC A0 read float - 0.41153 ADC A0 read 1A5 - 421 ADC A0 read float - 0.41153
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/rockpiS