Drives a text LCD screen with a PCF8574 or PCA8574 I²C expander module. Usually have a value in range 0x20-0x27 or 0x38-0x3F. Consult LCD/expander documentation to know the exact value.
Possible errors:
— Invalid I2C address
text-lcd-16x2-i2c
@/text-lcd-16x2-i2c
Deprecated: Use `xod-dev/text-lcd/text-lcd-i2c-16x2` instead.
Drives a text LCD screen with a PCF8574 or PCA8574 I²C expander module. Usually have a value in range 0x20-0x27 or 0x38-0x3F. Consult LCD/expander documentation to know the exact value.
Possible errors:
— Invalid I2C address
ADDRbyte
I²C address of the expander chip.
BLboolean
Backlight enable/disable
L1string
Text for the first line
L2string
Text for the second line
UPDpulse
Triggers new write
DONEpulse
Fires when write is done
C++ implementation
#pragma XOD evaluate_on_pin disable
#pragma XOD evaluate_on_pin enable input_UPD
#pragma XOD error_raise enable
{{#global}}
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
{{/global}}
struct State {
LiquidCrystal_I2C* lcd;
};
{{ GENERATED_CODE }}
void printLine(LiquidCrystal_I2C* lcd, uint8_t lineIndex, XString str) {
lcd->setCursor(0, lineIndex);
uint8_t whitespace = 16;
for (auto it = str.iterate(); it; ++it, --whitespace)
lcd->write(*it);
// Clear the rest of the line
while (whitespace--)
lcd->write(' ');
}
void evaluate(Context ctx) {
if (!isInputDirty<input_UPD>(ctx))
return;
State* state = getState(ctx);
auto lcd = state->lcd;
if (!state->lcd) {
uint8_t addr = getValue<input_ADDR>(ctx);
if (addr > 127) {
raiseError(ctx);
return;
}
state->lcd = lcd = new LiquidCrystal_I2C(addr, 16, 2);
lcd->begin();
}
printLine(lcd, 0, getValue<input_L1>(ctx));
printLine(lcd, 1, getValue<input_L2>(ctx));
lcd->setBacklight(getValue<input_BL>(ctx));
emitValue<output_DONE>(ctx, 1);
}