25 lines
1.1 KiB
Markdown
25 lines
1.1 KiB
Markdown
LiquidCrystal_PCF8574 hd44780 examples
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These examples require that the LiquidCrystal_PCF8574 library be installed.
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LiquidCrystal_PCF8574 library can be installed using the IDE library manager.
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It controls the LCD using an PCF8574 i/o expander backpack.
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The library assumes a paticular wiring between the PCF8574 and the LCD pins and a particular backlight circuit.
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```
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P0 - RS
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P1 - R/W
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P2 - E
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P3 - Backlight control (Active High)
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P4 - DB4
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P5 - DB5
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P6 - DB6
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P7 - DB7
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```
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Not all backpacks are wired up this way.
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If the actual wiring or backlight circuit does not match what the library expects, the examples will not work.
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Also, the examples must be modified to set the i2c address to match the i2c address of the PCF8574 chip.<br>
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**If the address in the sketch does not match the actual address of the chip, the example will not work**.
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The advantage of using hd44780 library and the hd44780_I2Cexp i/o class is that unlinke the LiquidCrystal_PCF8574 library the hd44780 library will automatically determine the i2c address, pin wiring, and backlight control configuration.
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