Building a Simple Raspberry Pi + Keypad IoT PoC with Zoho Flow

Building a Simple Raspberry Pi + Keypad IoT PoC with Zoho Flow

I want to share a simple IoT PoC I recently built that connects a Raspberry Pi to Zoho Flow and Zoho Creator. The goal was to send PIN input data from a hardware keypad to Zoho and trigger a servo and buzzer for visual/audible feedback. This can serve as a reference for others experimenting with IoT + Zoho integrations.

Hardware Used

  • Raspberry Pi 5

  • 4x4 Keypad

  • Small Servo Motor (SG90 or similar)

  • Active Buzzer

  • Powered by Raspberry Pi 5V (for PoC; external 5V recommended for multiple/stronger servos)


Software & Setup

  • Python 3 with gpiozero and RPi.GPIO

  • Zoho Flow Webhook to capture PIN input

  • Zoho Creator app to store data

How It Works

  1. User enters a 4-digit PIN on the keypad.

  2. Raspberry Pi sends the PIN, along with device ID and timestamp, to Zoho Flow.

  3. Zoho Flow forwards the data to a Creator app record.

  4. If the PIN is correct:

    • Servo rotates to “unlock” position for a short time.

  5. If the PIN is incorrect:

    • Buzzer beeps as a warning.

Key PoC Notes

  • Servo Stability: Using servo.detach() stops unnecessary PWM signals and prevents jitter.

  • Power: Small servo works with Pi’s 5V for PoC, but external 5V is recommended for long-term or multiple servo operation.

  • Time Stamps: Python datetime formatted to match Creator’s DateTime field.

Example Code Snippet

  1. from gpiozero import Servo
  2. import time

  4. servo = Servo(12)
  5. servo.value = 0     # Initialize
  6. time.sleep(0.5)
  7. servo.detach()      # Prevent jitter

  9. def unlock_servo():
  10.     servo.value = 0.6   # Move to unlock position
  11.     time.sleep(0.8)
  12.     servo.detach()      # Stop signal

Summary


This PoC shows that even with basic hardware and Python knowledge, you can integrate IoT devices with Zoho Flow and Creator. It’s a great starting point for experimenting with IoT + Zoho before moving to more complex setups or SaaS deployments.