Intercom Net Notifier

Home intercom notifier via Internet messenger DIY with ESP32

Header

Usage

Test key

Press to dispatch messaging manually as a test.

LED indication

Onboard LED

Slow blink (1sec period)
- Could not detect Wi-Fi device
Turn OFF
- Wi-Fi not connected
Turn ON
- Wi-Fi connected
Quick blink (200msec period)
- Signal detected and messaging process dispatched

Deployment

Circuit wiring

Circuit schematic

Set MCU communication secrets

Copy include/comm_secrets_template.h to include/comm_secrets.h, then fill out these values.

WIFI_SSID
WIFI_PASS
DISCORD_WEBHOOK_URL
LINE_CHANNEL_ACCESS_TOKEN

MCU program uploading

Connect MCU (ESP32) and PC with USB cable.

Open repository root directory by VSCode with PlatformIO extension. Then upload.

VSCode PlatformIO upload

Or you’d like to use CLI:

wget -O get-platformio.py https://raw.githubusercontent.com/platformio/platformio-core-installer/master/get-platformio.py
python3 get-platformio.py
rm get-platformio.py

pio run -t upload

Install to intercom system

Wire circuit input and home intercom system signal output.

Wiring 1

Wiring 2

Modification guide

Circuit

MCU board

You can migrate to other MCU board of MCU32 Dev Module. Migration requirements are:

It includes or connectable Arduino compatible Wi-Fi module
It has compatible development environment of Arduino

Isolation circuit

Resistors value and photo-coupler type have to be adapted to intercom system signal output specification. If you say the intercom signal output is clean and same voltage level as MCU IO, may be you can connect it directly (but keep isolated them is safe for the MCU).

Test key circuit

It’s optional. You can omit when it’s unnecessary.

If you omit it, comment main.c:13 line:

#define TEST_KEY_ENABLE

MCU program

PlatformIO config (when MCU board migrated)

platform and board selection in platformio.ini need to be modified with MCU board selection.

GPIO pin number

If you wish to use LED indication and the onboard (or external) LED pin is changed, main.c:18 have to be changed with connected pin number.

static const uint8_t  ONBOARD_LED     = 2;  // At ESP32 Dev Module

When you changed GPIO pin number with circuit wiring, main.c:19~21 have to be changed with connected pin number.

static const uint8_t  INTERCOM_SIG    = 4;

Messaging process

To add target messenger services, add posting function code via API to lib/messenger_post_simple/messenger_post_simple.cpp/.h. Then call it from main.c:61~62:

discord_webhook_post(DISCORD_WEBHOOK_URL, "Doorbell rang");
line_broadcast_post(LINE_CHANNEL_ACCESS_TOKEN, "Doorbell rang");

I recommend separate secrets data (e.g. access token) to include/comm_secrets.h.

This program posts to Discord and LINE. If it unnecessary, delete or comment the/these line(s).

License

CC0 1.0