Lesson 4 of 7

A real analog output: the DAC

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// A ramp on the DAC: A0 climbs from 0 to 5 V, again and again const int STEPS = 64; void setup() { Serial.begin(115200); analogWriteResolution(12); // 12 bits: levels 0-4095 } void loop() { for (int i = 0; i < STEPS; i++) { int level = (long)i * 4095 / (STEPS - 1); analogWrite(DAC, level); // DAC is another name for A0 delay(10); if (i % (STEPS / 4) == 0) { Serial.print("DAC "); Serial.print(level); Serial.print(" = "); Serial.print(level * 5.0 / 4095, 2); Serial.println(" V"); } } }

Stopped · Your code isn't running yet. Until you press Run, the board runs the program already on it.

Nothing printed yet. Press Run.

The R4 has what the R3 never had: a 12-bit DAC on A0 that puts out a true voltage, not PWM pulses. Step it from 0 to 5 V as a ramp and print the levels on the way.

A true voltage on A0
Stairs or a smooth ramp: pick the steps
The DAC gives a voltage, not power: a speaker needs an amplifier

Pin	Connects to	What it does
`A0`	A jumper to the breadboard, where a meter or a scope can probe it	DAC output: 0 to about 5 V.

Wire it in

Sensors and actuators this board drives, with the real connections.

All 6 parts on the Arduino UNO R4 page

A real analog output: the DAC

Try it yourself

Serial monitor

Checks

Break it

Parameters

Wire it in

A real analog output: the DAC

Try it yourself

Serial monitor

Checks

Break it

Parameters

Wire it in