Updating Firmware (Individual Devices)

Firmware upgrades do not necessarily need to be done via the cloud. If you are within NFC range of your OSS device, you can perform an on-site firmware upgrade, which is much faster, and also allows custom firmware to be loaded.

Firmware Over-the-Air

The OSS FOTA (Firmware Over-the-Air) process enables secure, cloud-managed firmware upgrades without disrupting device functions. Throughout the download phase, sensor sampling proceeds normally. The process can be broken down into three main parts:

• Triggering the FOTA
• Downloading the firmware
• Flashing the firmware

Firmware Downloading

During remote firmware upgrades, OSS downloads the firmware in chunks, retrieving each chunk over a secure HTTPS connection. This approach accommodates connectivity issues and sleep cycles, resuming as needed and displaying progress in Azure.

Firmware Flashing

After the download completes, the device will be flashed with the new firmware.

To prevent any unexpected firmware issues during the flashing process, please ensure the OSS device remains powered (battery power is sufficient). Loss of power during the flashing process may result in firmware corruption, which would require an on-site upgrade to restore the device.

Time Required

The time required for a remote firmware upgrade depends on the OSS device's operation mode and settings. Devices in "Low-Power" mode typically take longer to upgrade compared to those in "Always-on" mode. However, the settings for "Sensor Sampling Time" and "No. of Samples to Aggregate" also influence the upgrade duration.

Always-On Mode

In "Always-on" mode, only the "Sensor Sampling Time" setting is considered. For example, if the "Sensor Sampling Time" is set to 15 minutes, the device will take a sensor sample every 15 minutes and immediately sync it with the cloud. During each sync, a firmware chunk is downloaded. If there are 8 chunks, the process will take around 120 minutes.

Low-Power Mode

In "Low-Power" mode, the device still downloads a firmware chunk whenever it connects to the cloud. However, the frequency of these connections depends on both the "Sensor Sampling Time" and "No. of Samples to Aggregate" settings. The "Sensor Sampling Time" determines how often the device takes a sample, while the "No. of Samples to Aggregate" specifies how many samples must be collected before syncing with the cloud. For instance, if the "Sensor Sampling Time" is set to 15 minutes and the "No. of Samples to Aggregate" is set to 4, the device will take a sample every 15 minutes but will wait until 4 samples are collected before connecting to the cloud. In this case, the device connects approximately once every hour to sync data and download a firmware chunk. If there are 8 chunks to download, the process will take around 8 hours to complete.