# Chapter 12: Hardware Deep Dive — PWM and ADC

## Sample code

- Directory: `docs/os-on-arduino/code/12_hardware`

```bash
uv run pio run -d 12_hardware -t upload
uv run pio device monitor -b 115200
```

## Source code

The sketch for this chapter. Click a file name to expand. The code is mirrored automatically from the manuscript repository, so what you see here is always current.

:::{dropdown} `src/main.cpp` — 122 lines
:icon: code

[Open on GitHub](https://github.com/iory/learning-os-from-arduino/blob/main/docs/os-on-arduino/code/12_hardware/src/main.cpp)

```{literalinclude} ../../../../code/12_hardware/src/main.cpp
:language: cpp
:linenos:
```

:::

:::{dropdown} `include/hardware_pwm.h` — 159 lines
:icon: code

[Open on GitHub](https://github.com/iory/learning-os-from-arduino/blob/main/docs/os-on-arduino/code/12_hardware/include/hardware_pwm.h)

```{literalinclude} ../../../../code/12_hardware/include/hardware_pwm.h
:language: cpp
:linenos:
```

:::

:::{dropdown} `include/os_fault.h` — 46 lines
:icon: code

[Open on GitHub](https://github.com/iory/learning-os-from-arduino/blob/main/docs/os-on-arduino/code/12_hardware/include/os_fault.h)

```{literalinclude} ../../../../code/12_hardware/include/os_fault.h
:language: cpp
:linenos:
```

:::

:::{dropdown} `include/os_kernel.h` — 74 lines
:icon: code

[Open on GitHub](https://github.com/iory/learning-os-from-arduino/blob/main/docs/os-on-arduino/code/12_hardware/include/os_kernel.h)

```{literalinclude} ../../../../code/12_hardware/include/os_kernel.h
:language: cpp
:linenos:
```

:::

:::{dropdown} `include/raw_adc.h` — 75 lines
:icon: code

[Open on GitHub](https://github.com/iory/learning-os-from-arduino/blob/main/docs/os-on-arduino/code/12_hardware/include/raw_adc.h)

```{literalinclude} ../../../../code/12_hardware/include/raw_adc.h
:language: cpp
:linenos:
```

:::

:::{dropdown} `include/shell.h` — 23 lines
:icon: code

[Open on GitHub](https://github.com/iory/learning-os-from-arduino/blob/main/docs/os-on-arduino/code/12_hardware/include/shell.h)

```{literalinclude} ../../../../code/12_hardware/include/shell.h
:language: cpp
:linenos:
```

:::

:::{dropdown} `src/os_fault.cpp` — 170 lines
:icon: code

[Open on GitHub](https://github.com/iory/learning-os-from-arduino/blob/main/docs/os-on-arduino/code/12_hardware/src/os_fault.cpp)

```{literalinclude} ../../../../code/12_hardware/src/os_fault.cpp
:language: cpp
:linenos:
```

:::

:::{dropdown} `src/os_kernel.cpp` — 231 lines
:icon: code

[Open on GitHub](https://github.com/iory/learning-os-from-arduino/blob/main/docs/os-on-arduino/code/12_hardware/src/os_kernel.cpp)

```{literalinclude} ../../../../code/12_hardware/src/os_kernel.cpp
:language: cpp
:linenos:
```

:::

:::{dropdown} `src/shell.cpp` — 190 lines
:icon: code

[Open on GitHub](https://github.com/iory/learning-os-from-arduino/blob/main/docs/os-on-arduino/code/12_hardware/src/shell.cpp)

```{literalinclude} ../../../../code/12_hardware/src/shell.cpp
:language: cpp
:linenos:
```

:::


## Pitfalls

(Collected from reader questions — ask via
[GitHub Issues](https://github.com/iory/build-your-own-arduino-rtos/issues).)