darethehair Posted June 14, 2019 Posted June 14, 2019 Armbianmonitor: http://ix.io/1LLY Hello Folks! Already successfully running an RTL-SDR device (for Flight Tracking) and U-Blox NEO-6M GPS (for GPS/NTP) on my Orange Pi PC Plus, and now wanted to try a BME280 weather chip, but ran into problems talking to it. The 'i2cdetect' seems to be working fine: darren@frodo10:~$ sudo i2cdetect -y 0 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- -- -- -- 76 -- However, after many Googles with both C and Python code, I can't seem to successfully talk to this device In my last attempt (using bme280_sample.py and modifying the reference to 0x76, installing 'smbus2', etc.): darren@frodo10:~/Downloads$ sudo python bme280_sample.py Traceback (most recent call last): File "bme280_sample.py", line 138, in <module> setup() File "bme280_sample.py", line 133, in setup writeReg(0xF2,ctrl_hum_reg) File "bme280_sample.py", line 19, in writeReg bus.write_byte_data(i2c_address,reg_address,data) File "/usr/local/lib/python2.7/dist-packages/smbus2/smbus2.py", line 391, in write_byte_data ioctl(self.fd, I2C_SMBUS, msg) IOError: [Errno 6] No such device or address Does the 'ic2detect' output mean that I have everything wired up properly? Am I close to success?
martinayotte Posted June 14, 2019 Posted June 14, 2019 50 minutes ago, darethehair said: In my last attempt (using bme280_sample.py and modifying the reference to 0x76, installing 'smbus2', etc.): Did you tried modifying "bus_number = 1" to "bus_number = 0" ? You can also try using this python library instead of "smbus2" : https://github.com/duxingkei33/orangepi_PC_gpio_pyH3
darethehair Posted June 14, 2019 Author Posted June 14, 2019 7 hours ago, martinayotte said: Did you tried modifying "bus_number = 1" to "bus_number = 0" ? You can also try using this python library instead of "smbus2" : https://github.com/duxingkei33/orangepi_PC_gpio_pyH3 Hello! Thanks for your suggestions. Changing the 'bus_number' had no effect. I implemented the python library you suggested, but I have not found app code specifically to test the BME280. All of the code I have tested so far results in some sort of failure. The latest one (from blackmagicboxes) results in the following: darren@frodo10:~/Downloads/bmp280_p$ ./bme280_p Failed to open the bus. With successful 'i2cdetect', can I be confident my device is working and wired correctly i.e. that my problems are just a 'software' issue?
martinayotte Posted June 15, 2019 Posted June 15, 2019 12 hours ago, darethehair said: With successful 'i2cdetect', can I be confident my device is working and wired correctly i.e. that my problems are just a 'software' issue? I think so ... 12 hours ago, darethehair said: I implemented the python library you suggested You need to take your existing script and translate all the smbus calls to the new library.
darethehair Posted June 18, 2019 Author Posted June 18, 2019 Update: Success! Some articles that I read, including the one here, suggest using PA19/PA18 instead of PA12/PA11, so I swapped my wires around. I also followed the suggestion to wire SDO to GND as that article mentions. After doing this, and rebooting, the code I was trying started to work. Why? I have no idea, but I am happy. Next (small) hurdle -- deal with the expected distorted values being encountered while the BME280 sensor is in the same coffee can as the Orange Pi Thanks Martinayotte!
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