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我有以下代码不起作用并给我一条错误消息。我不太确定，但在错误消息中显示 i2c 地址 77。但 i2c-detect 显示 76。数字 48 是同一总线上的 ADC，它工作正常。

有谁知道可能导致问题的原因？我认为默认的 i2c 地址可能是 77。我的设备之一是 76。是否可以在 adafruit lib 中以某种方式更改它？

代码：

import board
import busio
import adafruit_bme280

# Create library object using our Bus I2C port
i2c = busio.I2C(board.SCL, board.SDA)
bme280 = adafruit_bme280.Adafruit_BME280_I2C(i2c)

# OR create library object using our Bus SPI port
# spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
# bme_cs = digitalio.DigitalInOut(board.D10)
# bme280 = adafruit_bme280.Adafruit_BME280_SPI(spi, bme_cs)

# change this to match the location's pressure (hPa) at sea level
bme280.sea_level_pressure = 1013.25

while True:
    print("\nTemperature: %0.1f C" % bme280.temperature)
    print("Humidity: %0.1f %%" % bme280.humidity)
    print("Pressure: %0.1f hPa" % bme280.pressure)
    print("Altitude = %0.2f meters" % bme280.altitude)
    time.sleep(2)

错误：

$ python3 i2ctest.py
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/dist-packages/adafruit_bus_device/i2c_device.py", line 184, in __probe_for_device
    self.i2c.writeto(self.device_address, b"")
  File "/home/pi/.local/lib/python3.7/site-packages/busio.py", line 101, in writeto
    return self._i2c.writeto(address, buffer, stop=stop)
  File "/home/pi/.local/lib/python3.7/site-packages/adafruit_blinka/microcontroller/generic_linux/i2c.py", line 46, in writeto
    self._i2c_bus.write_bytes(address, buffer[start:end])
  File "/home/pi/.local/lib/python3.7/site-packages/Adafruit_PureIO/smbus.py", line 308, in write_bytes
    self._device.write(buf)
OSError: [Errno 121] Remote I/O error

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.7/dist-packages/adafruit_bus_device/i2c_device.py", line 190, in __probe_for_device
    self.i2c.readfrom_into(self.device_address, result)
  File "/home/pi/.local/lib/python3.7/site-packages/busio.py", line 89, in readfrom_into
    return self._i2c.readfrom_into(address, buffer, stop=stop)
  File "/home/pi/.local/lib/python3.7/site-packages/adafruit_blinka/microcontroller/generic_linux/i2c.py", line 53, in readfrom_into
    readin = self._i2c_bus.read_bytes(address, end - start)
  File "/home/pi/.local/lib/python3.7/site-packages/Adafruit_PureIO/smbus.py", line 179, in read_bytes
    return self._device.read(number)
OSError: [Errno 121] Remote I/O error

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "i2ctest.py", line 9, in <module>
    bme280 = adafruit_bme280.Adafruit_BME280_I2C(i2c)
  File "/usr/local/lib/python3.7/dist-packages/adafruit_bme280.py", line 482, in __init__
    self._i2c = i2c_device.I2CDevice(i2c, address)
  File "/usr/local/lib/python3.7/dist-packages/adafruit_bus_device/i2c_device.py", line 69, in __init__
    self.__probe_for_device()
  File "/usr/local/lib/python3.7/dist-packages/adafruit_bus_device/i2c_device.py", line 192, in __probe_for_device
    raise ValueError("No I2C device at address: %x" % self.device_address)
ValueError: No I2C device at address: 77

I2C 检测：

i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- 48 -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- 76 --
4

2 回答 2

2

添加您的特定 I2C 地址，如文档中所述：

class adafruit_bme280.Adafruit_BME280_I2C(i2c, address=<sphinx.ext.autodoc.importer._MockObject object>)

它应该看起来像：

bme280 = adafruit_bme280.Adafruit_BME280_I2C(i2c, address=0x76)
于 2020-08-19T17:51:06.673 回答
0

我自己发现的。

问题确实是地址。lib 中的默认地址是 0x77。我的传感器板有 0x76。

但如果你仔细检查，你可以看到三个焊盘。左边和中间是由一条路线连接起来的。如果你切断这条路线（用针或其他东西）并连接中间和右边，地址更改为 0x77 并且库工作正常:)

这就是我的传感器的样子。

于 2020-06-03T13:33:36.643 回答