How to Update IoT devices with OTA

  • June 26, 2024

Introduction

When developing connected devices, one of the biggest challenges is updating the device firmware after it has been deployed. Firmware updates are crucial for the device lifespan, especially if the devices are in remote or hard-to-reach locations, or if manual updates would be too expensive.

Firmware updates might be needed to fix bugs, add new features, or change the device settings. It is essential to ensure that these updates are secure, so only authorized firmware is installed and malicious updates are blocked. The firmware can also be encrypted to prevent attacks.

What do you do when you have 1000s of smart devices active on the field and you need to update all of them without taking back to R&D center? this is what OTA can help you to achieve with wireless updates.

How OTA firmware process works?

  • After a software reset, the device starts with the secondary bootloader. This bootloader checks which software version is currently running. The bootloader and the main code use a shared register to store this information and to signal if there has been a firmware upgrade.
  • If no software is running, the device will either stay idle or check if an update is needed.
  • If there’s no upgrade flag, the current software will run. The bootloader then checks the code’s checksum to make sure it is correct.
  • If the checksums match, the code is valid. If they do not, there are errors in the code.
  • If the checksum does not match, the device will run the current software. If it matches, the device updates to the new software and starts running it.
  • This process allows the device to upgrade its firmware over-the-air.

How many ways to implement OTA firmware updates?

There are main 3 ways to update firmware by OTA methodology:

  • Direct to Cloud (Edge-to-Cloud)
  • Peer-to-Peer (Edge-to-Gateway-to-Cloud)
  • Gateway Mediator (Gateway-to-Cloud)

1. Direct to Cloud (Edge-to-Cloud)

What is Edge to Cloud OTA?

  • In the Direct to Cloud architecture, also referred to as Edge-to-Cloud (E2C), IoT devices connect directly to a cloud server to receive updates. This method is straightforward and allows each device to download updates independently.

Advantages of Edge to Cloud OTA:

  • Easy to implement if devices have good internet connectivity.
  • Each device is updated individually, reducing the risk of widespread failures.

Disadvantages of Edge to Cloud OTA:

  • Requires a reliable internet connection for all devices.
  • Can be inefficient if many devices need updates simultaneously.

How to implement Edge to Cloud OTA?

Step 1: Prepare the Update

  • Create the new software or firmware.
  • Package it securely (e.g., as a compressed file).

Step 2: Upload to Cloud

  • Use a cloud service (like AWS or Azure) to upload the update package.

Step 3: Notify Devices

  • Send a message from the cloud to each device informing them of the update.

Step 4: Download Update

  • Each device connects to the cloud and downloads the update.

Step 5: Install Update

  • Devices validate and install the update, ensuring it works correctly.

If you are still confused about OTA , you can discuss with our OTA expert to know the best way out.

2. Peer-to-Peer (Edge-to-Gateway-to-Cloud)

What is Edge to Gateway to Cloud OTA?

  • The Peer-to-Peer architecture, or Edge-to-Gateway-to-Cloud (E2G2C), involves a local gateway that manages multiple connected devices. The gateway downloads updates from the cloud and distributes them to the edge devices.

Advantages of Edge to Gateway to Cloud OTA:

  • Reduces internet bandwidth usage by downloading updates once for multiple devices.
  • Allows for local management of devices, which is useful in areas with poor connectivity.

Disadvantages of Edge to Gateway to Cloud OTA:

  • If the gateway fails, all connected devices may miss updates.
  • More complex troubleshooting since multiple devices are involved.

How to implement Edge to Gateway to Cloud OTA?

Step 1: Set Up Gateway

  • Install a local gateway that can communicate with both cloud and edge devices.

Step 2: Prepare Update

  • Create and package the new software or firmware as before.

Step 3: Upload to Cloud

  • Upload the update package to the cloud server.

Step 4: Gateway Downloads Update

  • The gateway checks for updates and downloads them from the cloud.

Step 5: Distribute Updates to Devices

  • The gateway sends the update package to each connected device.

Step 6: Install Update on Devices

  • Each device installs the update after validating it.

3. Gateway Mediator (Gateway-to-Cloud)

What is Gateway-to-Cloud?

  • This method involves a central gateway that receives updates from the cloud but does not directly update connected devices. Instead, it manages communications and data transmission.

Advantages of Gateway to Cloud:

  • Improves security by isolating devices from direct cloud access.
  • Reduces processing load on individual devices since they do not handle complex updates directly.

Disadvantages of Gateway to Cloud:

  • Only the gateway is updated; individual device updates must be managed separately.
  • Relies heavily on the performance of the gateway for successful updates.

How to implement Gateway to cloud?

Step 1: Set Up the Gateway

  • Install a central gateway that will manage communications between devices and the cloud.

Step 2: Prepare the Update

  • Create and package the new firmware as before.

Step 3: Upload to the Cloud

  • Upload the update package to a secure cloud server.

Step 4: Gateway Receives Updates

  • The gateway checks for new updates from the cloud and downloads them.

Step 5: Manage Device Updates

  • The gateway communicates with connected devices about when they need to update.

Step 6: Install the Update on Devices

  • Devices receive instructions from the gateway on how to download and install their specific updates.

What are advantages of OTA update?

Remote Management:

  • Updates can be delivered to devices without physical access, ideal for remote or hard-to-reach locations.

Cost-Effective:

  • Reduces the need for manual labor and travel expenses associated with updating devices.

Time Saving:

  • Allows for quick deployment of updates across all devices simultaneously.

Improved Security:

  • Ensures devices have the latest security patches and bug fixes promptly.

Scalability:

  • Facilitates the management of many devices efficiently.

Enhanced Features:

  • Enables the addition of new functionalities and improvements to devices without interrupting service.

User Convenience:

  • Minimizes disruption for users as updates are done seamlessly in the background.

Error Reduction:

  • Decreases the risk of human error associated with manual updates.

Real-Time Updates:

  • Allows for immediate deployment of critical updates in response to emerging threats or issues.

Extended Device Lifespan:

  • Keeps devices up-to-date and functional over a longer period, maximizing their usefulness.

Conclusion

In conclusion, OTA (Over-the-Air) updates have become an essential component in the management and evolution of connected devices. They enable seamless deployment of software patches, performance improvements, and new features without requiring physical intervention, ensuring that IoT devices, smartphones, and other embedded systems stay secure and up-to-date. By leveraging OTA updates, businesses can enhance user experience, reduce maintenance costs, and respond swiftly to emerging threats or technological advancements.

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