[quote author="cmdrk33n"]Avoiding the traces under D+ and D- will be a challenge.[/quote] The trace going to Q1's base could either be routed via under the uC avoiding the USB pins or relocating the pin to much more convenient pin near Q1.
As addition to what markus_b mentioned, group components by their function and place that group to their nearest connection.
Your board seems not finished. Anyway, I have few advice that I think you need to implement on this board. First, please do not run traces under Y1(Crystal) signal, these are your main clock signal and we don't want any interference into or from the clock traces and maybe keep the crystal circuit (including the 2 capacitors on the crystal) just a bit spaced from other components except on your uC. Avoid traces too under USB's D+ and D- traces. Keep those decoupling capacitors(0.1uF) near the uC's power pins as you can.
v2 and v2a are the same in terms of PCB and electrical connections, v2a only has additional text and labels for the contributors and design source of this card.
-Move to a bigger PCB 100mm x 60mm with mounting holes. -Testing area has more room now and with additional labels -Trimmer is now on the bottom. The first design was facing backwards :( -Add header for external probes. Female header for direct part testing and Male header for external probes connection. -Drill diameter for the LCD holes are now much bigger (2.8mm) -version is now (v1a)
[quote author="AndThen"]Your video challenge is, should you choose to accept it, not 1 but 3 "Old men" in age inapproriate t-shirts (Hello kitty?)[/quote]
I want to share what I have been trying to build, yes another programmable power supply. Hopefully this project will be my standard bench supply for most small projects and would like to build it step by step starting from displaying character on LCD, ADC read, DAC interfacing, keypad reading and working with the op-amps just for learning and fun. This will be a work in progress since this will be touched every time I have some spare time :) This link is the basis why I'm tempted to build the project.
Since this will be built part by part, I want it to be modular so I could work on each, then work on another one and later I could combine them all.
These are the modules in mind. -LCD and display driver -main microcontroller -DAC and op-amps -power supply section
Some of the components are scavenge from old printers and old boards. I just want to build this with minimal orders from online vendors.
Main components PIC18F458, I like to use this one first just for learning and maybe jump to a USB capable PICs soon. LCD from Nokia 3310, for settings display and menus 4 7-segments for a much clearer view on the actual voltage DAC716, this is a 16bit resolution DAC, I got this one from TI as samples. 4x3 Keyboard Step-down Transformers for logic voltage, DAC and op-amp's +/-12V and for the 12V main supply.
Initial output and specs 0~12V DC 1 Amp max. with current limiting voltage can be adjusted through the keypad target voltage and current limit will be viewed on the LCD actual voltage on the 7-segments
-move components (TX, RX, RX2) inward as to not fall within the 1.7 keepout distance. TX (7, 11), RX(5.5, 8.5), RX2 (3.5, 26) -Made the VCC trace from USB much fatter, and also the traces to TX -Aligned ICSP, UART and Expansion headers (Sorry I thought you dont like it to be on the same header)
