16×2 LCD (I2C)
A4=SDA · A5=SCL · addr 0x27
Circuit readouts
Vin (A6)
0.00V
3-bit Binary
000
Level
0 / 7
Reference step = 5V ÷ 8 =
0.625V
per level
LDR voltage (drag to simulate light intensity)
0V (Dark)
2.5V (Mid)
5V (Full sun)
LM339 Comparator outputs (thermometer code → 74HC148 input)