IOCAN

# Analog Output

## Overview

An **Analog Output** drives a real analog **voltage** on a hardware pin

(digital-to-analog conversion). Use it to feed the analog input of another ECU,

or to drive an analog gauge or meter, by turning a control value into a voltage.

You set an **output voltage range/reference** and a scaling that maps your input

(engineering) value onto a voltage within that range.

## Prerequisites & hardware

- Wire the output pin to the analog input it should drive, with a **common

  ground** between the controller and the receiving device.

- Pick a **range** the receiving input can accept (e.g. 0–5 V or 0–12 V); do not

  exceed its input rating.

- Have a source value (a map, driver or input) ready to command the output.

## Add it in the app

1. Add a new output and choose **Analog Output** as the type.

2. Select the **pin** and give it an **alias** (e.g. `Boost Gauge Drive`).

3. Choose the output **range**, then set the **in** and **out** scaling points.

4. Drive the output from a map/driver that supplies the input value.

## Settings reference

> Schema: `config/DacConfiguration.proto`.

| Setting | Meaning | Unit | Range / values | Notes |

|---|---|---|---|---|

| **Range** | Output voltage scale / reference | — | `5V`, `Internal 5 V`, `12V`, `Raw` | Sets the full-scale voltage the **Out** values refer to. `Internal 5 V` uses the controller's own 5 V reference; `Raw` outputs the unscaled DAC value. |

| **Enable interpolation** | Scale the input through the in/out points | — | on / off | On = interpolate input to output voltage; off = pass the value straight through. |

| **In min / In max** | Input (engineering) range to scale **from** | source unit | sint32 | The source low/high points. |

| **Out min / Out max** | Output voltage range to scale **to** | mV | sint32 | The voltage produced at In min / In max, within the selected range. |

**Scaling:** the input value is mapped from `In min…In max` to `Out min…Out max`

using [two-point interpolation](Scaling_and_Maps#two-point-interpolation).

## Common settings

Analog Output also uses the shared settings — alias and pin. See [Common IO Settings](Common_IO_Settings).

## Example — 0–5 V boost gauge drive

1. Type **Analog Output**, alias `Boost Gauge Drive`, on the gauge's pin.

2. **Range = 5V**, **Enable interpolation on**.

3. **In min/max** `0`/`300` (kPa) → **Out min/max** `0`/`5000` (mV).

4. Command it from the boost-pressure channel; 0 kPa gives 0 V, 300 kPa gives 5 V.

## Troubleshooting

- **Output voltage too high/low for the device:** pick a smaller **Range** or lower

  the **Out max** value.

- **Voltage doesn't change with the command:** check **Enable interpolation** is on

  and that the **In min/In max** span matches the source's real range.

- **Reads as a fixed offset on the receiver:** confirm a shared **ground** and that

  the receiver's range matches the selected **Range**.

## Related

- [PWM Output](PWM_Output) — for a switched/PWM signal instead of a voltage.

- [Tacho Output](Tacho_Output) — generated tacho/frequency signal.