Updating Module Firmware
This article describes several procedures to update firmware to a LL-RLP-20 or LL-RXR-27 module.
At the time of manufacturing, the Renesas microcontroller (Renesas R5F5116ADNE) on the LL-RLP-20/RXR-27 is programmed with the most recent firmware release. During this process, each module is assigned a unique MAC address and encryption keys. A bootloader is also loaded onto each MCU, to facilitate future firmware updates.
The preferred method to re-program a module is to flash firmware to the module via USB from a computer. To implement this method, the module's carrier board must include a USB-to-UART bridge. This allows the PC to interface with the module's UART bus. For example, the LL-RLP-20/RXR-27 evaluation board offered by Link Labs includes a Silicon Labs CP2104 USB-to-UART bridge.
Bootload the module while attached to a computer
This method assumes the module can interface to a computer via a USB-to-UART bridge. For example, the LL-RLP-20/RXR-27 evaluation board includes a Silicon Labs CP2104 USB-to-UART bridge. The firmware update can be achieved using (Method 1) the bootloader_upload_firmware.py script provided by Link Labs or (Method 2) using a terminal like Tera Term.
Method 1: Using Python with bootloader_upload_firmware.py
Place the desired encrypted firmware file, for example rlp_multi_mac.bin.encrypted, in the appropriate file path. The latest release of rlp_multi_mac.bin.encrypted can be found here.
Method 2: Using Tera Term
The bootloader on the LL-RLP-20/RXR-27 has a human-readable interface. You can view this interface by connecting a terminal to the module's UART.
Connect the module to your computer via USB and open a terminal. In this example, we're using Tera Term.
Boot the module in bootloader mode. This can be achieved using host interface commands, or by holding the BOOT pin low while rebooting the module. (This article describes how to place an LL-RLP-20/RXR-27 evaluation board in bootloader mode manually.) The Tera Term window will update with the following:
Link Labs Module Bootloader (RX111) Release v0.10 Firmware is...OK Enter a command: h - help u - upload encrypted firmware v - verify current firmware r - reset
Send the u character by typing 'u' while the Tera Term window is active. This will begin the bootloading process. Then immediately perform the following steps.
From Tera Term, select File > Transfer > XMODEM > Send. A file tree will appear; navigate to the appropriate encrypted binary file and click Send. (You can download the most recent release here.)Tera Term will send the new firmware to the module.
After successful completion, the Tera Term window will update with:
Any other response indicates an error in verifying the firmware image. Once the modules sends this response, the firmware has been validated and loaded, and you should send the r character to reboot the module into the new firmware.