Difference between revisions of "STM32 I²C LCD"
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The [[I²C]] extender is connected in the following way: | The [[I²C]] extender is connected in the following way: | ||
| − | [[File:I2c Module to LCD.png| | + | [[File:I2c Module to LCD.png|1000px]] |
| + | |||
| + | In other words, the 8 bits of the GPIO extender is mapped as follows: | ||
| + | |||
| + | {| class=wikitable | ||
| + | |- | ||
| + | ! Name | ||
| + | ! Function | ||
| + | |- | ||
| + | | P7 | ||
| + | | | ||
| + | |- | ||
| + | | P6 | ||
| + | | | ||
| + | |- | ||
| + | | P5 | ||
| + | | | ||
| + | |- | ||
| + | | P4 | ||
| + | | | ||
| + | |- | ||
| + | | P3 | ||
| + | | | ||
| + | |- | ||
| + | | P2 | ||
| + | | | ||
| + | |- | ||
| + | | P1 | ||
| + | | | ||
| + | |- | ||
| + | | P0 | ||
| + | | | ||
| + | |} | ||
== Miscellaneous Links == | == Miscellaneous Links == | ||
Revision as of 05:16, 2 June 2022
LCD Display modules are readily available and they are dirt cheap (< $2 typically). They come in different "resolutions" typically expressed as number of characters and number of lines. Common ones are 1602 (16 characters in 2 lines) and 2004 (20 characters in 4 lines).
The modules are interfaces by an 8 bit parallel data bus (can be operated in 4 bit mode) and some control signals:
These can of course be "driven" by an STM32 by interfacing these pins directly, but at a minimum that would tie up 8 GPIO pins for one display.
To cut down on the number of pins needed a GPIO extender can be used and because this approach is quite a lot easier a lot of the LCD modules come with an I²C GPIO extender already attached.
The I²C extender is connected in the following way:
In other words, the 8 bits of the GPIO extender is mapped as follows:
| Name | Function |
|---|---|
| P7 | |
| P6 | |
| P5 | |
| P4 | |
| P3 | |
| P2 | |
| P1 | |
| P0 |