Below is a link to the current firmware update file for the Digital Camera Hop Series products - DCHR receiver and DCHT transmitter. This is a zip file, after downloading extract it into a temporary folder. Use the Wireless Designer™ program to update firmware, instructions are found here.
Note: This is a link to the Wireless Designer firmware update file, which bundles the latest firmware for multiple products. Wireless Designer will automatically choose the right firmware images from the file. To update firmware in the DCHR receiver, Wireless Designer version 2.0.27 (Windows) or 2.0.22 (macOS) or higher is required.
DCHT versions 1.10 and higher work with M2R receivers using either 2.x or 3.x firmware, while DCHT versions 1.05 and lower work only with M2R receivers using 2.x firmware. All DCHT firmware versions work with the DCHR receiver.