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Code Issues Releases Wiki Activity

Add backlight handling for lcd_pcf8574 (#573)

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* Add backlight handling for lcd_pcf8574

Switch the backlight on or off by calling id(mydisplay).backlight()
or id(mydisplay).no_backlight() in lamda functions (assuming mydisplay
is the custom id for the LCD).

* Use abstract method


Co-authored-by: Attila Darazs <attila@darazs.com>
Co-authored-by: Otto Winter <otto@otto-winter.com>
This commit is contained in:
Attila Darazs
2019-06-03 19:36:00 +02:00
committed by Otto Winter
parent ebe64e24f1
commit 30a542e763
8 changed files with 45 additions and 16 deletions
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8
esphome/components/lcd_pcf8574/display.py
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@@ -1,7 +1,7 @@
import esphome.codegen as cg
import esphome.config_validation as cv
from esphome.components import lcd_base, i2c
from esphome.const import CONF_ID
from esphome.const import CONF_ID, CONF_LAMBDA
DEPENDENCIES = ['i2c']
AUTO_LOAD = ['lcd_base']
@@ -18,3 +18,9 @@ def to_code(config):
var = cg.new_Pvariable(config[CONF_ID])
yield lcd_base.setup_lcd_display(var, config)
yield i2c.register_i2c_device(var, config)
if CONF_LAMBDA in config:
lambda_ = yield cg.process_lambda(config[CONF_LAMBDA],
[(PCF8574LCDDisplay.operator('ref'), 'it')],
return_type=cg.void)
cg.add(var.set_writer(lambda_))

16
esphome/components/lcd_pcf8574/pcf8574_display.cpp
View File

@@ -6,9 +6,13 @@ namespace lcd_pcf8574 {
static const char *TAG = "lcd_pcf8574";
static const uint8_t LCD_DISPLAY_BACKLIGHT_ON = 0x08;
static const uint8_t LCD_DISPLAY_BACKLIGHT_OFF = 0x00;
void PCF8574LCDDisplay::setup() {
ESP_LOGCONFIG(TAG, "Setting up PCF8574 LCD Display...");
if (!this->write_bytes(0x08, nullptr, 0)) {
this->backlight_value_ = LCD_DISPLAY_BACKLIGHT_ON;
if (!this->write_bytes(this->backlight_value_, nullptr, 0)) {
this->mark_failed();
return;
}
@@ -29,7 +33,7 @@ void PCF8574LCDDisplay::write_n_bits(uint8_t value, uint8_t n) {
// Ugly fix: in the super setup() with n == 4 value needs to be shifted left
value <<= 4;
}
uint8_t data = value | 0x08; // Enable backlight
uint8_t data = value | this->backlight_value_; // Set backlight state
this->write_bytes(data, nullptr, 0);
// Pulse ENABLE
this->write_bytes(data | 0x04, nullptr, 0);
@@ -41,6 +45,14 @@ void PCF8574LCDDisplay::send(uint8_t value, bool rs) {
this->write_n_bits((value & 0xF0) | rs, 0);
this->write_n_bits(((value << 4) & 0xF0) | rs, 0);
}
void PCF8574LCDDisplay::backlight() {
this->backlight_value_ = LCD_DISPLAY_BACKLIGHT_ON;
this->write_bytes(this->backlight_value_, nullptr, 0);
}
void PCF8574LCDDisplay::no_backlight() {
this->backlight_value_ = LCD_DISPLAY_BACKLIGHT_OFF;
this->write_bytes(this->backlight_value_, nullptr, 0);
}
} // namespace lcd_pcf8574
} // namespace esphome

9
esphome/components/lcd_pcf8574/pcf8574_display.h
View File

@@ -9,13 +9,22 @@ namespace lcd_pcf8574 {
class PCF8574LCDDisplay : public lcd_base::LCDDisplay, public i2c::I2CDevice {
public:
void set_writer(std::function<void(PCF8574LCDDisplay &)> &&writer) { this->writer_ = std::move(writer); }
void setup() override;
void dump_config() override;
void backlight();
void no_backlight();
protected:
bool is_four_bit_mode() override { return true; }
void write_n_bits(uint8_t value, uint8_t n) override;
void send(uint8_t value, bool rs) override;
void call_writer() override { this->writer_(*this); }
// Stores the current state of the backlight.
uint8_t backlight_value_;
std::function<void(PCF8574LCDDisplay &)> writer_;
};
} // namespace lcd_pcf8574