> ## Documentation Index
> Fetch the complete documentation index at: https://support.customtypeone.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Reference: DIY USB Examples
You can create your own external triggers using Arduino, ESP32, Raspberry Pi, or other similar DIY hardware. The setup needs to be made per the below details:
Your DIY hardware must either:
1. Have its own power source separate from Sidekick so that it is powered on and running all the time to monitor the incoming power.
1. The Sidekick USB A port must be connected to your hardware to be monitored for 5V power.
2. When your DIY board detects power coming from the USB A port, you can perform any function of your choosing.
3. When your DIY board detects that power from the USB A port has stopped (alert snoozed/stopped), you can perform another function.
2. Run on USB A, 5V, 1 Amp or less and automatically perform your dedicated functions when powered on.
1. Plug your external hardware into Sidekick's USB A port.
2. If your hardware connects to WiFi, bluetooth, or has other delayed startup functions, you should only use the first DIY option above to ensure the alert function you have programmed runs immediately.
### What you need:
* ESP32 board (like a DevKitC or NodeMCU-ESP32)
* USB-A cable with exposed 5V (red) and GND (black) wires
* Two resistors for voltage divider (e.g., 10kΩ + 20kΩ → drops 5V to \~3.3V)
* Breadboard and jumper wires
### Wiring
USB Wire | Connect to
Red (5V) | Voltage divider → ESP32 GPIO (e.g., GPIO 18)
Black (GND) | ESP32 GND
### Voltage divider setup:
```
USB 5V → [20kΩ] → GPIO 18
↓
[10kΩ] → GND
```
This drops 5V down to \~3.3V safely.
### Example Code (ESP32, digital read)
```
const int usbPowerPin = 18; // GPIO18 gets the divided signal
bool lastState = LOW;
void setup() {
pinMode(usbPowerPin, INPUT);
Serial.begin(115200);
}
void loop() {
bool currentState = digitalRead(usbPowerPin);
if (currentState != lastState) {
if (currentState == HIGH) {
Serial.println("USB Power ON");
// YOUR ALERT START CODE GOES HERE
} else {
Serial.println("USB Power OFF");
// YOUR ALERT STOP CODE GOES HERE
}
lastState = currentState;
}
delay(100); // debounce / polling delay
}
```
**Important**:
* **Do NOT** connect 5V directly to ESP32 pins — always drop it to ≤3.3V.
* ESP32 pins are usually labeled **GPIO** on your board — you can pick most, but avoid strapping pins (like GPIO0, GPIO2, GPIO15).
* Use `Serial.begin(115200)` — ESP32 typically uses higher serial baud rates than Arduino Uno.
### What you need:
* Arduino Uno (or similar)
* USB-A cable with the 5V (red) and GND (black) wires exposed
* Connect the 5V wire to an Arduino digital pin (or analog for voltage measurement)
* Optionally use a resistor divider if needed
### Simple Example Code
This version monitors the 5V USB line connected to digital pin 2:
```
const int usbPowerPin = 2; // USB 5V line connected here
bool lastState = LOW;
void setup() {
pinMode(usbPowerPin, INPUT);
Serial.begin(9600);
}
void loop() {
bool currentState = digitalRead(usbPowerPin);
if (currentState != lastState) {
if (currentState == HIGH) {
Serial.println("USB Power ON");
// YOUR ALERT START CODE GOES HERE
} else {
Serial.println("USB Power OFF");
// YOUR ALERT STOP CODE GOES HERE
}
lastState = currentState;
}
delay(100); // debounce / polling delay
}
```
### Wiring
* **USB 5V (usually red)** → **Pin 2**
* **USB GND (usually black)** → **GND on Arduino**
**Important**: Ensure the USB power doesn't exceed 5V. If you're unsure, use a voltage divider (e.g., 10kΩ and 10kΩ) to cut voltage in half and measure with an analog pin.
## Example DIY Integrations
This is a list of examples found online for integrating various devices with Arduino, ESP32, etc. We have not tested any of these examples.
Native HomeKit on ESP32 or ESP8266
Bridge to Google Home with IFTTT, Firebase, or MQTT
Connect via MQTT, HTTP, or ESPHome
Trigger high-voltage devices like lamps, fans, or appliances
DC, servo, and stepper motors for robotics and automation
Electromagnetic lock or push/pull mechanisms
Trigger a web request, IFTTT, or cloud automation
Lockboxes, robotic arms, door locks
Control TV, lights, or other RF/IR devices
Show text or graphics
Trigger a siren for alerts or security systems
Trigger capture or stream images
Send SMS alerts with ESP32 and Twilio
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