1.硬件图

在这里插入图片描述

2.读取spi设备的寄存器值（方法1）

main.py

# coding=utf-8
# This is a sample Python script.
#0x9f是一个寄存器的地址
#bytearray(b'\xef@\x16'),是读取到的值,有需要的话 可以看一下ASCII，即0xef,0x40,0x16,一共三个字节
from driver import SPI
from driver import GPIO
print("-------------------spi test--------------------")
spi = SPI()
cs = GPIO()
spi.open("SPI0")
cs.open('cs')
readBuf = bytearray(3)
writeBuf = bytearray([0x9f])
print(writeBuf)
print(readBuf)
cs.write(0)
value1 = spi.write(writeBuf,1)
value2=spi.read(readBuf,3)
print(value1)
print(value2)
cs.write(1)
print(writeBuf)
print(readBuf)
cs.close()
spi.close()
print("-------------------spi test--------------------")

board.json

{
  "version": "1.0.0",
  "io": {
    "ADS1115": {
      "type": "I2C",
      "port": 1,
      "addrWidth": 7,
      "freq": 400000,
      "mode": "master",
      "devAddr": 72
    },
    "cs":{
      "type":"GPIO",
      "port": 15,
      "dir": "output",
      "pull":"pullup"
    },
    "mosi":{
      "type":"GPIO",
      "port": 16,
      "dir": "output",
      "pull":"pullup"
    },
    "miso":{
      "type":"GPIO",
      "port": 17,
      "dir": "output",
      "pull":"pullup"
    },
    "clk":{
      "type":"GPIO",
      "port": 18,
      "dir": "output",
      "pull":"pullup"
    },
    "SPI0": {
      "type": "SPI",
      "port": 0,
      "mode": "master",
      "freq": 2000000
      }

    },
    "debugLevel": "ERROR"
}

日志输出

-------------------spi test--------------------
bytearray(b'\x9f')
bytearray(b'\x00\x00\x00')
1
3
bytearray(b'\x9f')
bytearray(b'\xef@\x16')
-------------------spi test--------------------

3.读取spi设备的寄存器值（方法2）

main.py

# coding=utf-8
# This is a sample Python script.
from driver import SPI
from driver import GPIO
print("-------------------spi test--------------------")
spi = SPI()
cs = GPIO()
spi.open("SPI0")
cs.open('cs')
readBuf = bytearray(4)
writeBuf = bytearray([0x9f,0x00,0x00,0x00])
temp=bytearray(4)
print(writeBuf)
print(readBuf)
cs.write(0)
value=spi.writeRead(writeBuf,readBuf)
temp[0]=readBuf[0]
temp[1]=readBuf[1]
temp[2]=readBuf[2]
temp[3]=readBuf[3]
cs.write(1)
print(value)
print(temp)
print(temp[1:])
cs.close()
spi.close()
print("-------------------spi test--------------------")

board.json

{
  "version": "1.0.0",
  "io": {
    "ADS1115": {
      "type": "I2C",
      "port": 1,
      "addrWidth": 7,
      "freq": 400000,
      "mode": "master",
      "devAddr": 72
    },
    "cs":{
      "type":"GPIO",
      "port": 15,
      "dir": "output",
      "pull":"pullup"
    },
    "mosi":{
      "type":"GPIO",
      "port": 16,
      "dir": "output",
      "pull":"pullup"
    },
    "miso":{
      "type":"GPIO",
      "port": 17,
      "dir": "output",
      "pull":"pullup"
    },
    "clk":{
      "type":"GPIO",
      "port": 18,
      "dir": "output",
      "pull":"pullup"
    },
    "SPI0": {
      "type": "SPI",
      "port": 0,
      "mode": "master",
      "freq": 2000000
      }

    },
    "debugLevel": "DEBUG"
}

日志输出

-------------------spi test--------------------
bytearray(b'\x9f\x00\x00\x00')
bytearray(b'\x00\x00\x00\x00')
4
bytearray(b'\xff\xef@\x16')
bytearray(b'\xef@\x16')
-------------------spi test--------------------

4.Class-SPI

SPI open 打开spi write spi写操作,往指定寄存器内写数据 read spi读操作，从指定寄存器中读取数据 writeRead spi写和读操作，往寄存器写数据、从寄存器中取数据 close 关闭spi

SPI
- 实例化
  - spi=SPI()
- spi.open(params)
  - 作用：打开spi
  - 参数：params是一个字符串，需要预先在board.json中定义
  - 返回：0成功
- spi.write(writeBuf, len)
  - 作用：spi写操作,往指定寄存器内写数据
  - 参数：spi写操作需要传入一个writeBuf字节数组，数组中包含寄存器的地址和待写入的数据；还需传入writeBuf数组的长度len
  - 返回：写入的数据长度，即len
- spi.read()
  - 作用：spi读操作，从指定寄存器中读取数据
  - 参数：spi读操作需要传入一个readBuf字节数组，数组中包含指定寄存器的地址，即从哪个寄存器取数据，完成读操作后，所取得的寄存器中的数据被存放在ReadBuf中；还需传入readBuf数组的长度len
  - 返回：读取的数据长度，即len
- spi.writeRead(writeBuf, readBuf)
  - 作用：spi写和读操作，往寄存器写数据、从寄存器中取数据
  - 参数：writeBuf字节数组，数组中包含寄存器的地址；readBuf字节数组，数组中包含指定寄存器的地址，即从哪个寄存器取数据
  - 返回：读取到的数据长度
- spi.close()
  - 作用：关闭spi
  - 返回：0成功