I2C adapter address changing

[Skwerl77]

Hi Rob,

Thought I'd start a new thread here so the 3rd Gen Hardware thread doesn't get off track..

I used the Address Scanner you mentioned here (for background):

"06-16-2018, 05:41 PM
...
In the meantime you can still use those but you'll need to change the address in the controller sketch which is easy to do but first we need to know the address they are set to as default.

Here's a link to a sketch you can download which will scan the I2C devices and give the addresses for each of them, if you load this on the controller and open the serial monitor in the Arduino IDE you'll get the info. If you post them I'll pick out the proper address and let you know where to change it in the controller sketch.

https://playground.arduino.cc/Main/I2cScanner  "


The serial monitor gave me an address of 0X38. Does that sound right? I tried to move the address jumpers around on the adapter to get the next address, but apparently while doing so I shorted the power wires for too long and toasted my UNO board. 

Which one and where do I need to modify the sketch?

Thanks!

[Rob F]

Sorry to hear about your UNO, hope you have another board for your testing.

That address does sound right, the other addresses that show up are for the PCA9685, RTC and eeprom. You need to change that in the controller sketch, if you find line 89 and 90 you'll see powerbar1 and 2 with an address in brackets, change it there and it should work.

[Skwerl77]

Just double checking, the enable pin on the buffer isn't connected, right? Finally got the new one, putting it on now and noticed that SJ1 isn't populated (not that I'll need it for my application).

Thanks!

(Also got my new UNO, I'll verify the second address tonight and update the sketch; I did find lines 89 and 90, so should be all set with that)

[Rob F]

That's correct, the buffer has an internal pullup resistor so the enable pin doesn't need connection also SJ1 doesn't require anything.