The DPU-550 is an advanced upgrade daughterboard for the DRO-350 that plugs into the PIC microntroller socket.  It replaces the 8-bit PIC microcontroller with a far more powerful 32-bit ARM7 processor (see comparison table) with more program space for advanced features.  The PIC processor on the DRO-350 has served its task well, but it is getting antiquated compared to today's technology and more importantly, the program space is entirely used up by the DRO-350 software so there is no way to add more freatues without removing existing ones.

The DPU-550 not only includes an advanced processor, but it also adds a number of other commonly asked-for hardware features including:

What's even more exicting is that the DPU-550 software is completely open and available via the OpenDRO project.  This will allow anyone with an interest to contribute features or fixes.  Even if you don't feel comfortable contributing, you can look at the software for more insight on how it works.  The OpenDRO software is constantly evolving with new features so check the OpenDRO product page for a complete list.

The installation of the DPU-550 is designed to be as easy as possible.  It's installation is far easier than building a DRO-350.  The main part of the installation is to remove the existing PIC and solder in a pin header in its place.  Also, depending on which DPU-550 product you purchased, you might have to do some assembly of connectors or other portions of the PCB.  All of this is shown in more detail on the contruction page.