> For the complete documentation index, see [llms.txt](https://lcav.gitbook.io/dsp-labs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://lcav.gitbook.io/dsp-labs/passthrough.md).

# 2. AUDIO PASSTHROUGH

A "passthrough" can be viewed as the audio equivalent of "hello world". In this chapter, we will build a passthrough with the hardware and software components previously introduced. Moreover, we will point out some key specifications from the microphone and the DAC (Digital-to-Analog Converter) components so that our STM32 board can successfully interface with them. This will be done in [Section 2.1](/dsp-labs/passthrough/audio-io.md).

Using the CubeMX software, we will update the configuration of the microcontroller in [Section 2.2](/dsp-labs/passthrough/updating_stm32_peripherals.md). We will guide you through the wiring in [Section 2.3](/dsp-labs/passthrough/wiring.md). Finally, we will program our passthrough in [Section 2.4](/dsp-labs/passthrough/coding.md) using the SW4STM32 software.

Highlighted boxes, as shown below, specify a task for ***you*** to determine the appropriate solution and implementation.

{% hint style="info" %}
TASK: This is a task for you!
{% endhint %}

A passthrough is a great *sanity check* when first beginning with an audio DSP system. Moreover, it serves as a useful starting point for new projects as we will see in the following chapters when we develop more complicated programs!

![](/files/-LRgWYmuzA21Blw6Nzws)

*Figure: Final wiring.*


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://lcav.gitbook.io/dsp-labs/passthrough.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.