There must be something I don't understand.
I can not figure out how to use the multiplexer.
I am using an adafruit PCA9548
https://www.adafruit.com/product/5626
adafruit states
"In case you're wondering why this uses the PCA9548A not the TCA9548A, the PCA9548 is the 'fraternal twin sister' of the TCA9548 but is easier to get during the great chip shortage of 2022. It works exactly the same, just can't go down to 1.8V power which is OK because QT boards are 3V or 5V only anyways. You can still use any example code or library for the TCA9548"
For testing I am using a BME688.
With the BME688 at address 0x77 connected directly to the PI everything works.
Inserting the multiplexer in between the Pi and the BME688 and scanning the bus I get 0x70., the address for the multiplexer as expected.
I add the BME688 at address 0x70 because that is the only thing I can choose. I pick channel 0 because that is where the BME688 is plugged in.
Everything works.
But the address of the BME688 is now shown as 0x70
Now I want to add a INA219 to channel 0 at address 0x40.
I can't figure out how to do that since a scan of the bus only shows address 0x70.
I can add the ADS1115 on a different channel.
Is this the intended functionality?
I was hoping the attached could be accomplished.
I2C Conceptual.pdf (Size: 523.08 KB / Downloads: 111)
I can not figure out how to use the multiplexer.
I am using an adafruit PCA9548
https://www.adafruit.com/product/5626
adafruit states
"In case you're wondering why this uses the PCA9548A not the TCA9548A, the PCA9548 is the 'fraternal twin sister' of the TCA9548 but is easier to get during the great chip shortage of 2022. It works exactly the same, just can't go down to 1.8V power which is OK because QT boards are 3V or 5V only anyways. You can still use any example code or library for the TCA9548"
For testing I am using a BME688.
With the BME688 at address 0x77 connected directly to the PI everything works.
Inserting the multiplexer in between the Pi and the BME688 and scanning the bus I get 0x70., the address for the multiplexer as expected.
I add the BME688 at address 0x70 because that is the only thing I can choose. I pick channel 0 because that is where the BME688 is plugged in.
Everything works.
But the address of the BME688 is now shown as 0x70
Now I want to add a INA219 to channel 0 at address 0x40.
I can't figure out how to do that since a scan of the bus only shows address 0x70.
I can add the ADS1115 on a different channel.
Is this the intended functionality?
I was hoping the attached could be accomplished.
I2C Conceptual.pdf (Size: 523.08 KB / Downloads: 111)
(2022-10-21, 02:16 AM)RichFind Wrote: I am having trouble getting an INA219.
I believe I have connected it correctly. (see attached) The top portion shows my connections. The bottom half is from the chip supplier's spec sheet.
These are the settings:
This is the result:
Why am I getting null values?
(2022-10-19, 09:52 AM)nebosa Wrote:(2022-10-18, 11:22 PM)RichFind Wrote: Also
Working on installing a multiplexor.
Will let you know how things go.
Will be able to test with BPE688, INA218 and ADS115 (when available).
TIA
I expect a nice step by step guide if you were successful
Working on setting up the wiring for the individual sensors before going for multiplexing.
Just posted an issue I am having.
