After major issues with a lack of space in the V3 frame forcing everything to be removed if a single battery needed to be removed I decided to redesign the frame to be slightly larger but with a focus on ease of dissasemly. The plan is to have a box frame made from 20mm square aluminium and have removable aluminium plates on the sides.
New major additions will be two ethernet connected cameras for stereoscopic vision and a cheap 360 deg laser scanner.
The electronics are also being reworked to move away from a monolithic PCB to multiple smaller PCBs. This will make PCB design and construction a less risky business. To facilitate this I compared many connectors and finally settled on Modular connectors of sizes 4,6 and 8. They are cheap, easy to assemble and secured to each other.
Every major component is supposed to be connected through a small ethernet switch. This way my processing board and the Parallella have a high speed interconnect that is also addressable from over the wifi for easy debugging of each component. Minor components will be connected with the modular connectors.
The processing board is similar to Zircon 4, the major differences is 16MB external RAM, 100Mbit Ethernet and much less connectors for potential-maybe-features. Instead it will feature multiple modular 4 and 6 connectors for connecting extra boards that themselves will handle any potential future interfacing needs. An example is the previous LCD required 16 wires but with the new system a single modular 6 connector would carry serial data to a tiny STM32F030 microcontroller at the LCD that handles the interfacing and cpu offloading.
A separate Power board is being designed with the goals of measuring currents and voltages with more accuracy than before (16-bit ADCs instead of 12-bit, no switching regulator) and also have on-board 100W charging circuitry. There will only be a single 5V 9A power rail for all the boards which will then each locally step-down to 3.65V and then linearly regulate to a stable 3.3V.
Code and documentation at svn://exuvo.se/kartobot/trunk.