- External reference: https://docs.infinitime.io/en/latest/user-documentation/index.html
firmware is software running on the embedded hardware of a device.
InfiniTime has three distinct firmwares:
InfiniTime is the operating system. The bootloader is responsible for safely applying firmware updates and runs before booting into InfiniTime. The recovery firmware is a special application firmware than can be loaded by the bootloader on user request. This firmware can be useful in case of serious issue, when the main application firmware cannot perform an OTA update correctly.
OTA (Over The Air) refers to updating of the firmware over BLE (Bluetooth Low Energy).
update the firmware on their device wirelessly.
DFU (Device Firmware Update) is the file format and protocol used to send the update of the firmware to the watch over-the-air. InfiniTime implements the (legacy) DFU protocol from Nordic Semiconductor (NRF).
The bootloader is run right before booting into InfiniTime
2 functionalities using the push button:
Push the button until the pine cone is drawn in blue to force the rollback of the previous version of the firmware, even if you’ve already validated the updated one Push the button until the pine cone is drawn in red to load the recovery firmware. This recovery firmware only provides BLE connectivity and OTA functionality.
Open NRFConnect. Swipe down in the Scanner tab and wait for your device to appear: (add pic) Tap on the Connect button on the right of your device. NRFConnect will connect to your PineTime and discover its characteristics. Tap on the DFU button on the top right: (add pic) Select Distribution packet (ZIP): (add pic) Find the DFU file (pinetime-mcuboot-app-dfu-x.x.x.zip) you downloaded previously, the DFU transfer will start automatically. When the transfer is finished, your PineTime will reset and restart on the new version of InfiniTime! Don’t forget to validate your firmware. In the InfiniTime go to the settings (swipe right, select gear icon) and Firmware option and click validate. Otherwise after reboot the previous firmware will be used
Firmware updates must be manually validated. If the firmware isn’t validated and the watch resets, the watch will revert to the previous firmware. This is a safety feature to prevent bricking your device with faulty firmware.