hi all,
have here Arduino nano with I2C-Expander PCA 9548 A,
which distributes I2C-Adresses for Display (0x27), mcp23017 (0x75),
SX1509 (0x3F) found by wellknown I2C-scanner.
So far all works ok.
But connecting the PWM-Expander PCA 9685 (unmodified adress) with the
I2C-Expander, the scanner must find 0x40, but does not find any additional I2C-adress.
have checked all connections..no error to see..
Did you select the correct channel on the PCA9548A?
Since all the devices you mentioned have distinct I2C addresses, what is the function of the PCA9548A I2C expander in your circuit?
What are the display, MCP23017, SX1509 and PCA9685 hooked up to?
The Arduino's I2C bus?
One of the I2C expander's busses?
Several of the I2C busses?
I'm assuming they're hooked up to the Arduino's I2C since you say they're being detected by the I2C scanner and haven't mentioned modifying it to permit the other I2C devices to be detected on one or more of the I2C expander's busses.
A proper schematic would answer many questions.
Try reversing SCL and SDA to the PCA9548, If that does not work post an annotated schematic showing how you wired it, include all components, modules, etc.
Why would you use an I3C expander for three modules, it is unnecessarily complicating your system. !2C will support about 112 devices.
If you want to use the expander post an annotated schematic showing exactly how it is connected and all items including components, power sources, grounds, etc.
Which one?
There is one here specifically for the pca9548/tca9548: Arduino Wiring & Test | Adafruit TCA9548A 1-to-8 I2C Multiplexer Breakout | Adafruit Learning System which scans all devices on all channels.
i'm sorry, that i can't serve here in the moment..
my girlfriend had an car-accident
and i'm serving here at hospital as far as needed
i'm glad to see that my girlfriend is on good way after accident..so i
can proceed with this theme time by time..
here the first version i tried with i2c-bus-expander..not working well
at pwm-expander and mcp23017 for touch-pad-input..
have tested input with mc23017 : seems not to work over the bus expander
have tested pwm-output with pwm-expander as written before (and with oand without pullup-resistors : seems not to work over the bus expander
so my idea to avoid these problems is like schematic no 2
PWM-driving with A.nano : works fine separately
Touch-Pad-input over mc23017 at I2C : works fine separately
is to test next soon in orchestral..all components together
at least..this does Not work..no result on scanner..
wether external pullup resitors bultin or not..
think i'll return to Arduino Mega..only to use a A.mega-shield
for easily plug in/out for sketch-upload with my pc (win7 or win 10,
on Win11 at Notebook depending on Version-Updates Not working)..
but avoiding expander-special-problems..
