How Do Shared Bikes Communicate? Inside the IoT Tech Behind Smart Locks

Smart Lock

The core hardware of a shared bike is the smart lock, which provides control and positioning functions. Inside the lock are an embedded chip (communication module), a GPS module, and an IoT SIM card.

Manufacturers embed a SIM card with a unique number, enabling 2G/3G/4G communication with the cloud. The lock reports its GPS location and lock status to the cloud in real time.

Chip Power Supply

The communication module needs power, which is generated by a coil that spins when the rider pedals, charging the battery through electromagnetic induction.

QR‑Code Unlocking

Each bike has a unique QR code. Users scan it with a mobile app, which connects to the bike via Bluetooth, sends the QR data to the cloud, and receives an unlock command that activates the electromechanical lock.

Payment System

The cloud platform calculates usage time from lock/unlock events, determines the fee, and interfaces with WeChat or Alipay to complete payment.

Bluetooth Fallback

In areas with poor cellular coverage, the lock cannot receive cloud commands. The system then uses Bluetooth: the cloud sends an unlock key to the user's phone, which pairs with the lock to open it, offering faster and more reliable unlocking than network‑based methods.

GPS Positioning

Two major bike‑sharing apps handle positioning differently: one shows the phone’s location on a map, while the other obtains the bike’s GPS data directly. GPS accuracy can be affected by urban canyons, leading to mismatches between reported and actual positions.

IoT Technologies

Shared bikes employ three main IoT communication methods: 2G/3G/4G modules, Bluetooth, and NB‑IoT. NB‑IoT is favored for its wide coverage, massive device support, and low power consumption, making it a mainstream choice for bike‑sharing deployments.