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/ IoT · Hardware · MQTT · Headless

IoT Commerce: Selling via Smart Fridges

The future is headless hardware. How to integrate Shopify with MQTT, Embedded C, and Smart Mirrors.

AB
Alex B.
IoT Commerce: Selling via Smart Fridges

“Hey Fridge, order milk.” This is not sci-fi. It is 2025. IoT (Internet of Things) Commerce is the ultimate expression of Headless. The “Head” is not a website. It is a screen on a Samsung Fridge, or a Dash Button, or a Connected Car. The backend is still Shopify.

The Protocol: MQTT vs HTTP

Browsers speak HTTP. Sensors speak MQTT. HTTP is request/response (heavy). MQTT is pub/sub (lightweight). A sensor on a coffee machine publishes specific data: “Beans Level: 10%”. We need a Broker (AWS IoT Core / Mosquitto) to translate this.

Architecture

  1. Device: ESP32 microcontroller in the Coffee Machine.
  2. State: Detects bean low. Publishes to topic device/123/beans.
  3. Cloud Function: Subscribes to topic. Triggers logic.
  4. Shopify: Adds Product ID COFFEE_BEANS to User’s Cart (or auto-orders).

Auto-Replenishment Logic

The holy grail of Recurring Revenue (subscription). You don’t need to “Sell” the customer every month. The machine sells for you. Use Case: Printer Ink. HP Printers know when cyan is low. They order cyan. Risk: User Consent. You cannot just charge a credit card. Flow:

  1. Device sends “Low Ink” signal.
  2. System sends Push Notification: “Ink low. Order now? [Yes/No]” (See Push Notifications).
  3. User clicks “Yes”.
  4. Order created via Shopify Admin API.

Embedded Code (C++)

On the hardware side, you are writing C++ or MicroPython.

// Arduino / ESP32 Code
#include <PubSubClient.h>

void loop() {
  int sensorValue = analogRead(A0);
  if (sensorValue < 100) { // Tank empty
    char payload[50];
    sprintf(payload, "{\"deviceId\": \"123\", \"level\": %d}", sensorValue);
    client.publish("maison/coffee/refill", payload);
    delay(3600000); // Wait 1 hour to avoid spam
  }
}

Smart Mirrors (Retail)

In the flagship store, the mirror is a screen. It uses RFID to detect the shirt you brought into the fitting room. It displays: “We also have this in Blue. Tap to request.” Technically, this is a web app running on a Raspberry Pi kiosk mode. It uses WebSockets for real-time inventory checks.

Security Implications

If I hack your Fridge, can I buy 500 gallons of milk? Yes. IoT Security is notoriously weak. Defense:

  1. Mutual TLS (mTLS): Device must have a private certificate.
  2. Rate Limiting: Max 1 order per day per device.
  3. Human Loop: Orders > $50 require App confirmation.

7. NFC and QR Codes: The “Dumb” IoT

You don’t always need a CPU. Sometimes a sticker is enough. NFC (Near Field Communication) tags cost $0.10. Stick one on the washing machine. User taps phone -> Opens App Clip (Instant) -> “Reorder Detergent” Pre-filled. This is “Physical Cookies”. We use Mainson Code Dynamic Links to track which exact sticker was tapped, attributing the sale to the specific physical location (e.g., “Gym Locker Room”).

8. Voice Commerce (Alexa/Siri)

“Alexa, reorder my vitamins.” This requires:

  1. Account Linking: OAuth2 flow connecting Alexa ID to Shopify Customer ID.
  2. Voice Skill: AWS Lambda function handling the intent.
  3. Payment Token: Using Amazon Pay or Apple Pay on file. The challenge is “Discovery” (hard to browse products). The opportunity is “Replenishment” (easy to repeat order).

10. The 5G Impact

IoT was limited by WiFi (Consumer) or 2G (Industrial). 5G enables Massive Machine Type Communication (mMTC). 1 million devices per square km. Smart Vending Machines in the middle of a park (no WiFi). Connected Cars ordering coffee at 60mph. Low latency allows real-time bidding for “Energy Pricing” or “Toll Roads” via the embedded wallet.

11. Wearable Commerce

The Apple Watch is an IoT device. “Tap to Pay” is boring. “Biometric Ordering” is the future. “Your heart rate is high during this workout. Buy Electrolytes?” This is arguably dystopian, but it is technically possible via HealthKit APIs integrated with Shopify. We build these integrations for fitness brands (Privacy-First, of course).

13. The 5G Revolution: Massive MQTT

4G was for phones. 5G is for Things. mMTC (Massive Machine Type Communication) allows 1 million sensors per square km. This means we can tag individual products, not just pallets. A luxury handbag can have an embedded eSIM/NFC chip. It communicates its location, temperature, and humidity (important for leather) back to the cloud. If the bag is stolen, it can be bricked (Digital Twin Concept). This opens up “Product as a Service” models where you lease the bag and pay per use.

Why Maison Code Discusses This

At Maison Code, we bridge the gap between Bits and Atoms. Most web agencies are scared of C++ or Soldering irons. We are not. We prototype hardware + software solutions. We understand that the future of commerce is “Ambient”. It’s not about a screen; it’s about the environment serving the user. We build the secure, scalable MQTT backends that power these invisible experiences.

15. Conclusion

IoT Commerce sounds futuristic, but it’s just “Headless” taken to its logical conclusion. The API is the store. The Device is just the display. Whether it’s a fridge, a car, or a watch, the transaction is the same. The brands that embed themselves into the user’s physical life will win the loyalty war.

Building connected hardware?

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