https://github.com/zachzion762/teensy41-intercom

Teensy 4.1–based intercom system with MQTT + Home Assistant integration. Hardware, firmware, and wiring diagrams for a modular smart-home panel
https://github.com/zachzion762/teensy41-intercom

3d-printing arduino automation electronics embedded-systems hardware-designs home-assistant iot mqtt smart-home smarthome stl-files teensy41

Last synced: 30 days ago
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Teensy 4.1–based intercom system with MQTT + Home Assistant integration. Hardware, firmware, and wiring diagrams for a modular smart-home panel

• Host: GitHub
• URL: https://github.com/zachzion762/teensy41-intercom
• Owner: zachzion762
• License: mit
• Created: 2025-08-25T19:43:11.000Z (about 1 month ago)
• Default Branch: main
• Last Pushed: 2025-08-25T20:25:39.000Z (about 1 month ago)
• Last Synced: 2025-08-25T21:32:48.556Z (about 1 month ago)
• Topics: 3d-printing, arduino, automation, electronics, embedded-systems, hardware-designs, home-assistant, iot, mqtt, smart-home, smarthome, stl-files, teensy41
• Language: C++
• Homepage: https://www.youtube.com/watch?v=SxNvHAskOwU
• Size: 37.1 MB
• Stars: 1
• Watchers: 0
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

Awesome Lists containing this project

README

          
# Teensy 4.1 Intercom – MQTT Button Panel

## Demo Video

[![Watch the demo](https://img.youtube.com/vi/SxNvHAskOwU/0.jpg)](https://www.youtube.com/watch?v=SxNvHAskOwU)

Turns a Teensy 4.1 + Ethernet kit into a **12-button MQTT panel** with Home Assistant discovery.  

Each button is exposed as a binary sensor in Home Assistant, with \ON\/\OFF\ state, plus an availability topic.

---

## ✨ Features

- 12 inputs (using \INPUT_PULLUP\, press = LOW)

- Native Ethernet with **QNEthernet**

- MQTT via **PubSubClient**

- Home Assistant auto-discovery

- Availability + periodic re-announce

- 3D printed bracket for mounting

---

## 🖼️ System Overview

![System Overview](hardware/system_overview_diagram.jpg)

This diagram shows how the Teensy fits into the network:  

buttons → Teensy 4.1 → Ethernet → MQTT broker → Home Assistant.

---

## 🔌 Wiring Diagram

![Wiring](hardware/wiring_diagram.jpg)

Each button is wired from a Teensy pin to **GND**. Pins used are:

\\\

BTN1..BTN12 → 1, 3, 5, 7, 9, 10, 12, 24, 26, 28, 30, 32

\\\

All pins use \INPUT_PULLUP\, so pressing pulls the pin LOW.  

**Other side of every button = GND (shared).**

---

## 📸 Hardware Photos

| Printing Brackets | Empty Enclosure | Wiring | Final Mount |

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

| ![Brackets](hardware/photos/3d_print_brackets1.jpg) | ![Empty1](hardware/photos/empty1.jpg) | ![Wiring1](hardware/photos/wiring1.jpg) | ![WoodBlock](hardware/photos/3d_print_brackets5.jpg) |

> More photos in [hardware/photos](hardware/photos).  

> If your exact filenames differ, update the links above (they were sanitized to remove spaces/parentheses).

---

## 🎥 3D Print Timelapse

[▶ 3D print timelapse video](hardware/photos/3D_print_timelapse.mp4)

---

## 🛠️ 3D Printed Parts

- [\Teensy_4.1_Ethernet_Mount.stl\](hardware/Teensy_4.1_Ethernet_Mount.stl)  

  Bracket to hold the Teensy with the PJRC Ethernet kit.

---

## 📡 MQTT

See [docs/mqtt-topics.md](docs/mqtt-topics.md).

---

## 🏠 Home Assistant Integration

Entities appear automatically under **MQTT → Binary Sensors** (discovery).  

![HA Discovery](docs/screenshots/ha_discovery.png)  

![HA Entities](docs/screenshots/ha_entities.png)

---

## ⚙️ Build Instructions (Arduino IDE 2.3.6)

1. **Boards Manager**: install “Teensy by PJRC” → select **Teensy 4.1**  

2. **Library Manager**: install  

   - **QNEthernet** (Shawn Silverman)  

   - **PubSubClient** (Nick O’Leary)  

3. Copy \firmware/TeensyIntercom/secrets_example.h\ → \secrets.h\ and edit with your broker details.  

   (\secrets.h\ is ignored by Git — safe to commit the project without it.)  

4. Open \firmware/TeensyIntercom/TeensyIntercom.ino\  

5. **Verify** → **Upload**

After upload, check MQTT:

\\\

intercom/availability = online

intercom/button/N = ON/OFF

\\\

---

## 📜 License

MIT — see [LICENSE](LICENSE).

---

## 🙏 Credits

- **QNEthernet** by Shawn Silverman  

- **PubSubClient** by Nick O’Leary  

- Built with Arduino IDE 2.3.6

## Bill of Materials

See [hardware/BOM.md](hardware/BOM.md) for the full parts list.