This is a deep redesign of MVFD 16S8D Panel Rev.1.0 project which fixes minor and major issues and finally solves the fundamental problem of some parts becoming obsolete. Let’s reiterate the reasons which were the main driving forces of the project to come into existence:
– Single power source (+5V) which makes it possible to drive the panel from a USB port or batteries, high and filament voltages are generated internally;
– No need in transformer which is usually a non-off-the-shelf part resulting in cheaper, lightweight and compact solution;
– Pulse filament drive is used, an equivalent of AC (as opposed to DC) eliminating brightness gradient across the length of the VFD glass;
– Popular, inexpensive and widely available chips are used to generate filament and high voltages, very low risk of them becoming obsolete;
– Feedback in high voltage generator circuitry helps to achieve constant brightness regardless of number segments and digits lit up;
– Adjustable high voltage to get highest brightness without reducing VFD lifetime;
– Adjustable DC offset for filament voltage to maximise VFD brightness and cut off ghosting effect;
– An inexpensive and popular VFD driver is used which is produced by several silicone manufactures under different names but in the same package with pin-to-pin compatibility also reducing the risk of the part becoming obsolete;
– Low power mode;
– An infra red (IR) receiver;
– A buzzer;
– An RGB LED;
– A photocell (light sensor);
– A dedicated VFD driver is controlled by SPI-like two wire iterface taking care of display refresh and offloading main CPU (even Arduino Uno can cope with the job);
– Most parts are through hole making it very easy to assemble even by DIY enthusiasts with average soldering skills;
The top and bottom component layout is given below. No dramatic changes in comparison with Rev.1.0, same PCB dimensions, same mounting hole locations, same locations for parts on the top side to maintain compatibility with the previous design. On the bottom side the bulky parts representing the PSU are grouped together allowing to free up space for mating with MVFD Serial Backpack.
The PCB layout is given below. It utilises 2 layers to take advantage of good PCB manufacturer deals like Itead Studio. The design is also tailored to a specific Itead prototyping offer which is 100x50mm and comes at $25 for 10 color boards without shipment (or even $14.90 for green boards!)
The 3D model of the whole assembly is available at 3D Warehouse so it becomes really easy to design additional peripheral to mate with the panel, to get a good understanding how the panel looks like or even make use of the 3D models of the parts for some other projects.
Once again, no facelifting on the top side, it looks pretty much the same way as Rev.1.0 looked:
The bottom side looks significantly different now mostly due to totally new design of PSU. Note, that in order to minimise dimensions, the inductor is placed horizontally but nothing prevents it from mounting vertically, it is just a matter of personal taste and size restrictions.
The video below shows how the panel integrates with previously designed MVFD Serial Backpack: