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WIO Display Multiplex


On most Display break-out boards the I2C address cannot be changed.
Up to 8 displays on the same address can be multiplexed with a TCA9548A chip on I2C address 0x72.
If beside 0x72 also 0x73 is available as multiplexer, up to 16 displays will be supported.


TCA9548A I2C address

I2C address 0x70 is default for the TCA9548A, but is also in use by 7-Segment displays.
The address pins should be connected as follows:

Multiplexer I2C Address A0 A1 A2 Rocrail displays
1 0x72 open VIN(+) open 1…8
2 0x73 VIN(+) VIN(+) open 9…16

The 16 displays should be all the of the same type,


If I2C address 0x72 is available at start up, the WIO will switch to multiplexing 8 or 16 SSD1306 on the I2C addresses 0x3C.
In this mode address 0x3D, for the second display, will be ignored.


The Bus is used for the WIO ID, and the Display number for selecting between 1…16. (16 * 0x3C)
Fast clock and scrolling is not supported in multiplex mode.

wio/wio-displaymultiplex-en.txt · Last modified: 2023/12/09 17:35 by rjversluis