Trying to determine the source of sensor/transmitter noise, and I am wondering if I am overloading the multiplexer. I have 8 I2C devices connected to 1 BOB-16784 multiplexer, each drawing 46mA at 5.3Vcc. I am not an EE so am not exactly sure what to look for on the TI datasheet. Is the max Icc = 100mA (pg. 4) the number I should be considering? Thus meaning I need 4 MUX boards?
Where are you getting your 5 volt supply from? The mux and your 8 devices need about 400mA, if you’re overloading the 5 volt supply, that could generate noise.
I’m using a Meanwell DDR-15G-5 (3A max) connected to a 24VDC power supply.
Is the noise in the power circuit or i2c bus? If i2c, have you disabled any i2c pull-up resistors? You should only leave the mux’s set intact and disable the other 8 if enabled
The “noise” (actually more like a few second step function) is in the read data I’m getting from the transmitter. There is no pullup resistor on the transmitters (Atlas Scientific EZO pH), but the electrical isolation board uses hardwired 10Kohm. Datasheet pg. 5
So the I2C bus
Share a couple photos of the wiring/connections