Table of Contents
WIO Display Multiplex
- WIO Setup | WIO Control | User Bitmaps | WIO Firmware | WIO Mobile | Cable | LEDScript | IOScript | WIOpi
Introduction
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.
Setup
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,
WIO
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.
Rocrail
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.