mirror of https://github.com/periph/devices
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
51 lines
1.5 KiB
Go
51 lines
1.5 KiB
Go
// Copyright 2025 The Periph Authors. All rights reserved.
|
|
// Use of this source code is governed under the Apache License, Version 2.0
|
|
// that can be found in the LICENSE file.
|
|
|
|
package hd44780
|
|
|
|
import (
|
|
"periph.io/x/conn/v3/gpio"
|
|
"periph.io/x/conn/v3/i2c"
|
|
"periph.io/x/devices/v3/pcf857x"
|
|
)
|
|
|
|
const (
|
|
// Name is the LCD pin name, and the integer value is the GPIO
|
|
// number (not physical) of the PCF8574 I2C GPIO Expander.
|
|
pcf_d4 = 4
|
|
pcf_d5 = 5
|
|
pcf_d6 = 6
|
|
pcf_d7 = 7
|
|
pcf_rsPin = 0
|
|
pcf_enablePin = 2
|
|
pcf_backlightPin = 3
|
|
pcf_rwPin = 1
|
|
)
|
|
|
|
// This function returns a display configured to use the pcf8574 i2c backpacks.
|
|
//
|
|
// # Product Information
|
|
//
|
|
// https://www.handsontec.com/dataspecs/I2C_2004_LCD.pdf
|
|
//
|
|
// This function creates a PCF8574 backpack device with the required pin
|
|
// configuration. To use this, get an I2C bus, and call this function with the
|
|
// bus, i2c address, number of rows, and columns.
|
|
func NewPCF857xBackpack(bus i2c.Bus, address uint16, rows, cols int) (*HD44780, error) {
|
|
pcf, err := pcf857x.New(bus, address, pcf857x.PCF8574)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// R/W is connected on this backpack. Set it to low.
|
|
_ = pcf.Pins[pcf_rwPin].Out(gpio.Low)
|
|
|
|
// Create our gpio.Group
|
|
gr, _ := pcf.Group(pcf_d4, pcf_d5, pcf_d6, pcf_d7, pcf_rsPin, pcf_enablePin, pcf_backlightPin)
|
|
grPins := gr.Pins()
|
|
reset := grPins[4].(gpio.PinOut)
|
|
enable := grPins[5].(gpio.PinOut)
|
|
bl := grPins[6].(gpio.PinOut)
|
|
return NewHD44780(gr, &reset, &enable, &bl, rows, cols)
|
|
}
|