【赛昉科技昉·星光RISC-V单板计算机试用体验】Ubuntu Server 22.04 UART读取ZE08-CH2O 甲醛数据

一、安装ubuntu22.04 server系统

1. 下载镜像ubuntu-server-22.04-riscv64-visionfive-29042022

2. 在linux下使用etcher将镜像写入到SD卡；

   

3. 将SD卡插入到板卡SD卡卡槽中；

4. ssh 账号: user 密码:star5

二、修改dtb文件，并使能uart1

1. 获取linux源代码，并编译源代码linux源代码

   sudo apt update
   sudo apt upgrade
   
   sudo apt install gcc-riscv64-linux-gnu
   
   git clone https://github.com/starfive-tech/linux.git
   
   cd linux
   
   make CROSS_COMPILE=riscv64-linux-gnu- ARCH=riscv visionfive_defconfig
   
   make CROSS_COMPILE=riscv64-linux-gnu- ARCH=riscv
   
   

2. 修改/linux/arch/riscv/boot/dts/starfive/jh7100-common.dtsi中与uart有关的接口

   

   

   

   sudo cp linux/arch/riscv/boot/dts/starfive/jh7100-starfive-visionfive-v1.dtb /boot/dtb-5.17.5-visionfive-foobar-29042022
   sudo sudo update-grub
   
   

   UART和DEV映射

   

三、硬件连接

四、软件代码

1. 串口类python代码

import serial
import serial.tools.list_ports

class MySerial(object):

def init(self):

self.ser = None
def get_port_list(self):
    port_list = list(serial.tools.list_ports.comports())
    return port_list

def open_serial_port(self, port, baud):
    try:
        self.ser = serial.Serial(port, baud, timeout=0.3, interCharTimeout=0.05)
    except Exception as e:
        self.ser = None
        raise Exception(e)

def close_serial_port(self):
    if self.ser == None:
        raise Exception("no selected serial")
    try:
        self.ser.close()
        self.ser = None
    except Exception as e:
        raise Exception(e

2. 工具类代码

   class MyTools(object):
   def init(self):
   
   pass
   def bytes_to_strs(self, bytes_value):
   
   arry = ''.join(['%02x '% b for b in bytes_value])
   
   return (arry.upper())
   
   

3. 甲醛类代码：

   class ze08_ch20(object):
   def init(self) -> None:
   
   self.tools = MyTools()
   
   self.serial = MySerial()
   
   self.serial.open_serial_port('/dev/ttyS2', 9600)
   
   '''
   
   self.recv_thread_ = threading.Thread(target=self.recv_thread)
   
   self.recv_thread_.start()
   
   '''
   
   self.recv_thread()
   def calc_checksum(self, bytes_value):
   
   checksum = 0
   
   for byte_ in bytes_value:
   
   checksum += byte_
   
   checksum = checksum % (0xff + 1)
   
   if checksum == 0xff:
   
   return True
   
   return False
   def recv_thread(self):
   
   recv_buffer = bytes()
   
   #print("hello world")
   
   while True:
   
   try:
   
   recv_buffer += self.serial.read()
   
   except Exception as e:
   
   print(str(e))
   
   if len(recv_buffer) < 9:
   
   time.sleep(0.01)
   
   #print(len(recv_buffer))
   
   continue
   
   else:
   
   if recv_buffer[0] != 0xff:
   
   recv_buffer = recv_buffer[1:]
   
   else:
   
   if len(recv_buffer) >= 9:
   
   #print(len(recv_buffer))
   
   phase_buffer = recv_buffer[:9]
   
   recv_buffer = recv_buffer[9:]
   
   print(self.tools.bytes_to_strs(phase_buffer))
   
   if self.calc_checksum(phase_buffer) == True:
   
   int_formaldehyde = int.from_bytes(phase_buffer[4:6], byteorder='big')
   
   #print(int_formaldehyde)
   
   float_formaldehyde = int_formaldehyde /1000.0 *1.25
   
   print(float_formaldehyde)
   
   time.sleep(0.001)
   
   

4. main代码

   if __name__=="__main__":
   my_statistics = ze08_ch20()
   
   

   五、执行代码获取甲醛值