Digital and analog signals in SerialCraft

Minecraft redstone has 16 levels, from 0 to 15. SerialCraft's hardware protocol uses 0–255 in both directions. These ranges apply to 0.5.0-beta on Minecraft 26.2.

Understanding the conversion helps you write compatible firmware and diagnose signals that appear stuck, dim or noisy.

Digital: off or on

A module set to Minecraft → Hardware and DIGITAL sends zero when off and 255 when on. For a channel named led_verde, the messages are:

led_verde:255
led_verde:0

Each message ends with a newline. In the other direction, any positive received value becomes full-strength redstone in DIGITAL mode. This is useful for buttons, switches and alarms.

Analog: keep intermediate levels

ANALOG keeps intermediate numeric values. USB and TCP still carry digital text; Minecraft does not send an analog voltage through the cable.

hardware value = redstone × 17
redstone ≈ hardware value / 17, rounded to the nearest level

Redstone	Hardware value
0	0
1	17
3	51
7	119
10	170
15	255

For example, an incoming value of 128 becomes redstone level 8 in ANALOG mode.

PWM is not necessarily a continuous analog voltage

On an Arduino Uno R3, analogWrite(9, 128) normally produces PWM: rapid on/off pulses with approximately half the time spent on. This can control the apparent brightness of an LED, but it is not the same as a DAC output.

A potentiometer read with analogRead(A0) normally produces 0–1023 on an Uno R3. Map it to 0–255 before sending:

int adc = analogRead(A0);
int wireValue = map(adc, 0, 1023, 0, 255);
Serial.print("pot_val:");
Serial.println(wireValue);

Compare both modes

1. Configure an I/O Module as Hardware → Minecraft, channel pot_val.
2. Use the potentiometer example.
3. Observe gradual redstone changes in ANALOG mode.
4. Change only the signal type to DIGITAL.
5. Compare the gradual reading with off/on output.

A lever has only two states; changing its module to ANALOG cannot create intermediate input levels.

Common mistakes

• A very dim LED: old firmware may treat 1 as on; the current protocol sends 255 for digital on.
• Readings jump between levels: the sensor has more resolution than redstone and may also have electrical noise. Filter or add a small deadband in the firmware.
• Direction and terminals are mixed up: data direction and the green/red redstone connector roles are separate settings. See the I/O Module guide.

Continue with the protocol reference or connection troubleshooting.