接口定义
整机接口定义
LKD3566提供了丰富的接口，具体如下图：
MIC 使用
使用以下命令可以录制音频文件，支持wav、mp3等格式。
录制双声道的16位小端格式的音频，采样率为48000Hz，然后保存为001.wav文件。
- Cmd
- C
- Python
arecord -Dhw:0,0 -r48000 -f S16_LE -c2 > 001.wav
• -Dhw:0,0 指定了录音设备，0,0 是card 0 device 0，也就是第一个声卡的第一个设备。
• -r48000 指定了采样率，单位是Hz，48000表示每秒采样48000次。
• -f S16_LE 指定了采样格式，S16_LE表示有符号的16位小端格式，也就是每个采样点占用2个字节，低位在前，高位在后。
• -c2 指定了声道数，2表示双声道，也就是立体声。
• > 001.wav 指定了输出文件，>表示重定向标准输出到文件，001.wav表示文件名，wav表示文件格式。
create audio_record.c
#include <stdio.h>
#include <stdlib.h>
#include <alsa/asoundlib.h>
#define SAMPLE_RATE 44100 // Replace SAMPLE_RATE with a local variable
#define CHANNELS 2 // Replace CHANNELS with a local variable
int main(int argc, char *argv[]) {
const char *device = "hw:0,0"; // Set the audio device
snd_pcm_t *pcm_handle;
snd_pcm_hw_params_t *params;
unsigned int sample_rate = SAMPLE_RATE; // Use a modifiable local variable
int channels = CHANNELS; // Use a modifiable local variable
int pcm, dir;
snd_pcm_uframes_t frames = 32;
FILE *file = fopen("001.wav", "wb");
if (!file) {
perror("Unable to create audio file");
return 1;
}
// Open PCM device
if ((pcm = snd_pcm_open(&pcm_handle, device, SND_PCM_STREAM_CAPTURE, 0)) < 0) {
fprintf(stderr, "Unable to open PCM device %s: %s\n", device, snd_strerror(pcm));
fclose(file);
return 1;
}
// Set hardware parameters
snd_pcm_hw_params_alloca(¶ms);
snd_pcm_hw_params_any(pcm_handle, params);
snd_pcm_hw_params_set_access(pcm_handle, params, SND_PCM_ACCESS_RW_INTERLEAVED);
snd_pcm_hw_params_set_format(pcm_handle, params, SND_PCM_FORMAT_S16_LE);
snd_pcm_hw_params_set_channels(pcm_handle, params, channels); // Use the variable channels
snd_pcm_hw_params_set_rate_near(pcm_handle, params, &sample_rate, &dir); // Use the variable sample_rate
// Apply parameters
if ((pcm = snd_pcm_hw_params(pcm_handle, params)) < 0) {
fprintf(stderr, "Unable to set hardware parameters: %s\n", snd_strerror(pcm));
snd_pcm_close(pcm_handle);
fclose(file);
return 1;
}
// Get buffer size
snd_pcm_hw_params_get_period_size(params, &frames, &dir);
int buffer_size = frames * channels * 2; // 2 bytes per channel
char *buffer = (char *)malloc(buffer_size);
// Write WAV file header
fwrite("RIFF", 1, 4, file);
fwrite("----", 1, 4, file); // Placeholder
fwrite("WAVE", 1, 4, file);
fwrite("fmt ", 1, 4, file);
int subchunk1_size = 16;
short audio_format = 1;
fwrite(&subchunk1_size, 4, 1, file);
fwrite(&audio_format, 2, 1, file);
fwrite(&channels, 2, 1, file); // Use the variable channels
fwrite(&sample_rate, 4, 1, file); // Use the variable sample_rate
int byte_rate = sample_rate * channels * 2;
fwrite(&byte_rate, 4, 1, file);
short block_align = channels * 2;
fwrite(&block_align, 2, 1, file);
short bits_per_sample = 16;
fwrite(&bits_per_sample, 2, 1, file);
// Write WAV data header
fwrite("data", 1, 4, file);
fwrite("----", 1, 4, file); // Placeholder
printf("Starting recording...\n");
// Start recording
int total_data_size = 0;
while (1) {
pcm = snd_pcm_readi(pcm_handle, buffer, frames);
if (pcm == -EPIPE) {
snd_pcm_prepare(pcm_handle);
} else if (pcm < 0) {
fprintf(stderr, "Recording failed: %s\n", snd_strerror(pcm));
break;
}
fwrite(buffer, 1, buffer_size, file);
total_data_size += buffer_size;
}
// Update WAV file size
fseek(file, 4, SEEK_SET);
int file_size = total_data_size + 36;
fwrite(&file_size, 4, 1, file);
fseek(file, 40, SEEK_SET);
fwrite(&total_data_size, 4, 1, file);
// Clean up resources
free(buffer);
snd_pcm_drain(pcm_handle);
snd_pcm_close(pcm_handle);
fclose(file);
printf("Recording complete\n");
return 0;
}
gcc audio_record.c -o audio_record -lasound
./audio_record
Install the PyAudio library:
sudo apt update
sudo apt install python3-pip
sudo apt install portaudio19-dev
pip3 install pyaudio
create audio_record.py
import wave
import pyaudio
# Audio format parameters
FORMAT = pyaudio.paInt16 # 16-bit PCM
CHANNELS = 2
RATE = 48000 # Sample rate
CHUNK = 4096 # Buffer size
# Create a PyAudio object
p = pyaudio.PyAudio()
# Open an audio stream
stream = p.open(format=FORMAT,
channels=CHANNELS,
rate=RATE,
input=True,
frames_per_buffer=CHUNK)
# Open a WAV file for writing
wf = wave.open('001.wav', 'wb')
wf.setnchannels(CHANNELS)
wf.setsampwidth(p.get_sample_size(FORMAT))
wf.setframerate(RATE)
print("Recording...")
# Record audio data
try:
while True:
data = stream.read(CHUNK)
wf.writeframes(data)
except KeyboardInterrupt:
print("Recording stopped.")
# Clean up
print("Recording complete. Saved as 001.wav")
stream.stop_stream()
stream.close()
p.terminate()
wf.close()
python audio_record.py
LINE 使用
使用第一个声卡的第一个设备播放001.wav文件。
- Cmd
- C
- Python
aplay -D hw:0,0 001.wav
• -D hw:0,0 指定了播放设备，hw:0,0 是card 0 device 0，也就是第一个声卡的第一个设备。
• 001.wav 指定了音频文件，wav表示文件格式，001表示文件名。
Install the ALSA library and its development headers:
sudo apt update
sudo apt install libasound2-dev
create audio_play.c
#include <stdio.h>
#include <stdlib.h>
#include <alsa/asoundlib.h>
int main(int argc, char *argv[]) {
const char *device = "hw:0,0"; // Set audio device
const char *filename = "001.wav"; // Audio file path
snd_pcm_t *pcm_handle;
snd_pcm_hw_params_t *params;
unsigned int sample_rate = 44100; // Sample rate
int pcm, dir;
snd_pcm_uframes_t frames;
FILE *file;
char *buffer;
int buffer_size;
// Open audio file
file = fopen(filename, "rb");
if (!file) {
perror("Unable to open audio file");
return 1;
}
// Open PCM device
if ((pcm = snd_pcm_open(&pcm_handle, device, SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
fprintf(stderr, "Unable to open PCM device %s: %s\n", device, snd_strerror(pcm));
fclose(file);
return 1;
}
// Set hardware parameters
snd_pcm_hw_params_alloca(¶ms);
snd_pcm_hw_params_any(pcm_handle, params);
snd_pcm_hw_params_set_access(pcm_handle, params, SND_PCM_ACCESS_RW_INTERLEAVED);
snd_pcm_hw_params_set_format(pcm_handle, params, SND_PCM_FORMAT_S16_LE);
snd_pcm_hw_params_set_channels(pcm_handle, params, 2);
snd_pcm_hw_params_set_rate_near(pcm_handle, params, &sample_rate, &dir);
// Apply parameters
if ((pcm = snd_pcm_hw_params(pcm_handle, params)) < 0) {
fprintf(stderr, "Unable to set hardware parameters: %s\n", snd_strerror(pcm));
snd_pcm_close(pcm_handle);
fclose(file);
return 1;
}
// Get frame size and buffer size
snd_pcm_hw_params_get_period_size(params, &frames, &dir);
buffer_size = frames * 4; // 2 channels, each sample is 2 bytes
buffer = (char *) malloc(buffer_size);
// Play audio
while (fread(buffer, 1, buffer_size, file) > 0) {
if ((pcm = snd_pcm_writei(pcm_handle, buffer, frames)) == -EPIPE) {
snd_pcm_prepare(pcm_handle);
} else if (pcm < 0) {
fprintf(stderr, "Playback failed: %s\n", snd_strerror(pcm));
}
}
// Cleanup
free(buffer);
snd_pcm_drain(pcm_handle);
snd_pcm_close(pcm_handle);
fclose(file);
printf("Playback completed\n");
return 0;
}
gcc audio_play.c -o audio_play -lasound
./audio_play
Install the PyAudio and wave libraries:
sudo apt update
sudo apt install python3-pyaudio
create audio_play.py
import pyaudio
import wave
def play_audio(filename):
# Open WAV audio file
with wave.open(filename, 'rb') as wf:
# Initialize PyAudio
p = pyaudio.PyAudio()
# Configure audio stream
stream = p.open(format=p.get_format_from_width(wf.getsampwidth()),
channels=wf.getnchannels(),
rate=wf.getframerate(),
output=True)
# Read and play audio data
data = wf.readframes(1024)
while data:
stream.write(data)
data = wf.readframes(1024)
# Stop and close audio stream
stream.stop_stream()
stream.close()
# Terminate PyAudio
p.terminate()
print("Playback completed")
# Play file
play_audio('001.wav')
python3 audio_play.py
HDMI/DP 说明
xrandx命令可以查看当前HDMI连接：
neardi@3588:~$ xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
HDMI-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
1920x1080 60.00*+ 60.00 50.00 30.00 24.00
4096x2160 24.00
3840x2160 30.00 25.00 24.00
1920x1080i 60.00 50.00
1280x720 60.00 60.00 50.00 50.00 30.00 24.00
720x576 50.00 50.00
720x480 59.94 59.94 59.94
HDMI-2 disconnected (normal left inverted right x axis y axis)
DSI-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
1920x1080 60.00*+
DP-1 disconnected (normal left inverted right x axis y axis)
完整节点
HDMI1：/sys/devices/platform/display-subsystem/drm/card0/card0-HDMI-A-1/
ETH 说明
可以通过调试串口、ssh或者adb来查看IP地址，例如：
neardi@3588:~$ ifconfig -a
enP2p33s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.65 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::7df7:e74d:497e:345d prefixlen 64 scopeid 0x20<link>
ether 62:ea:fb:ca:95:e7 txqueuelen 1000 (Ethernet)
RX packets 2548 bytes 210938 (210.9 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 338 bytes 46899 (46.8 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 140 base 0xd000
Wi-Fi 说明
通过如下命令查看当前Wi-Fi型号：
cat /sys/bus/sdio/devices/mmc2\:0001\:1/vendor
cat /sys/bus/sdio/devices/mmc2\:0001\:1/device
0x02d0:0xaae8:AP6275S.0x024c:0xb852:RTL8852.0x024c:0xd723:RTL8723DS.0x024c:0xc821:RTL8821CS.0x1ffe:0x6316:FD7352S。
Connect Wi-Fi:
-
Cmd
-
C
-
Search Wi-Fi:
sudo nmcli device wifi rescan
- Show all Wi-Fi:
nmcli dev wifi list
- Connect Wi-Fi:
sudo nmcli device wifi connect neardi_5G password neardi_pwd
• neardi_5G 是WiFi 网络(SSID) 的名称。
• neardi_pwd 是连接到该WiFi 网络所需的密码。
• sudo 用于确保nmcli 具有管理网络连接所需的权限，因为在某些系统上连接到WiFi 网络可能需要管理权限。
create connect_wifi.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
void connect_to_wifi(const char *ssid, const char *password) {
char command[256];
// Create the WPA configuration file without the -e option
snprintf(command, sizeof(command), "echo 'network={\\n ssid=\"%s\"\\n psk=\"%s\"\\n}' | sudo tee /etc/wpa_supplicant/wpa_supplicant.conf", ssid, password);
if (system(command) != 0) {
perror("Failed to create wpa_supplicant.conf");
return;
}
// Run wpa_supplicant
if (system("sudo wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf") != 0) {
perror("Failed to start wpa_supplicant");
return;
}
// Obtain an IP address
if (system("sudo dhclient wlan0") != 0) {
perror("Failed to obtain an IP address");
}
}
int main() {
const char *ssid = "neardi_5G";
const char *password = "neardi_pwd";
connect_to_wifi(ssid, password);
return 0;
}
gcc connect_wifi.c -o connect_wifi
sudo ./connect_wifi
SSD的使用
- 插入Sata硬盘，打开终端，输入
sudo fdisk -l命令查找USB驱动器的设备名称，一般为/dev/sda1或/dev/sdb1等。 - 使用
sudo mkdir /backup命令创建一个新目录。 - 输入
sudo mount /dev/sda1 /backup命令（假设挂载点为/backup）挂载Sata硬盘分区。
TF卡使用
1.查看已连接设备
lsblk 命令可以列出系统中的所有块设备，包括硬盘、SSD、USB 驱动器、TF 卡等。
输出示例：
neardi@LPA3588:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
mmcblk0 179:0 0 115.2G 0 disk
├─mmcblk0p1 179:1 0 1M 0 part
├─mmcblk0p2 179:2 0 4M 0 part
├─mmcblk0p3 179:3 0 4M 0 part
├─mmcblk0p4 179:4 0 64M 0 part
├─mmcblk0p5 179:5 0 128M 0 part
├─mmcblk0p6 179:6 0 32M 0 part
└─mmcblk0p7 179:7 0 115G 0 part /
mmcblk0boot0 179:32 0 4M 1 disk
mmcblk0boot1 179:64 0 4M 1 disk
mmcblk1 179:96 0 58.6G 0 disk
├─mmcblk1p1 179:97 0 4M 0 part
├─mmcblk1p2 179:98 0 4M 0 part
├─mmcblk1p3 179:99 0 64M 0 part
├─mmcblk1p4 179:100 0 128M 0 part
├─mmcblk1p5 179:101 0 32M 0 part
└─mmcblk1p6 179:102 0 58.4G 0 part /media/neardi/47a3b5be-53bd-4d96-b3d0-e095c4879f34
默认挂载在/media/neardi/，如果你想挂载在其他地方，请按照以下说明操作：
//umount
sudo umount /media/neardi
//mount
sudo mount /dev/mmcblk0p1 /mnt/tfcard
如果权限不足，执行 sudo chown -R neardi:neardi /media/neardi.
RTC时钟
LKD3566使用HYM8563作为RTC时钟。
如何修改RTC时钟为'2025-11-11 12:00:00'
- Cmd
- C
#关闭网络时间协议（NTP）的服务，使得RTC时钟不受网络时间的影响
timedatectl set-ntp false
#设置RTC时钟的时间为2025年11月11日12时00分00秒
timedatectl set-time '2025-11-11 12:00:00'
#将RTC时钟的时间同步到系统时钟，使得系统时钟和RTC时钟保持一致，可加在/etc/init.d/rockchip.sh中
hwclock --hctosys
create time_setter.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
void exec_command(const char *cmd) {
int ret = system(cmd);
if (ret != 0) {
fprintf(stderr, "Command failed: %s\n", cmd);
exit(1);
}
}
// Set system time
void set_system_time(const char *time_str) {
char cmd[128];
snprintf(cmd, sizeof(cmd), "timedatectl set-time '%s'", time_str);
exec_command(cmd);
}
// Disable NTP
void disable_ntp() {
exec_command("timedatectl set-ntp false");
}
// Synchronize hardware clock to system clock
void sync_hwclock_to_system() {
exec_command("hwclock --hctosys");
}
// Print help information
void print_usage() {
printf("Usage: time_setter -t <time>\n");
printf(" -t <time> Set system time (format: 'YYYY-MM-DD HH:MM:SS')\n");
printf(" -h Show help\n");
}
int main(int argc, char *argv[]) {
if (argc != 3) {
print_usage();
return 1;
}
const char *time_str = NULL;
int opt;
while ((opt = getopt(argc, argv, "t:h")) != -1) {
switch (opt) {
case 't':
time_str = optarg;
break;
case 'h':
default:
print_usage();
return 0;
}
}
if (time_str == NULL) {
fprintf(stderr, "Error: Time argument is required\n");
print_usage();
return 1;
}
// 1. Disable NTP
disable_ntp();
// 2. Set system time
set_system_time(time_str);
// 3. Synchronize hardware clock to system clock
sync_hwclock_to_system();
printf("Time has been set to: %s\n", time_str);
return 0;
}
gcc -o time_setter time_setter.c
./time_setter -t "2025-11-11 12:00:00"