Shared Projects by SyncChannelBlog

What to do when you have a partial reel of 74AHCT08 chips burning a hole in your pocket? Design a 20 Input AND gate of course.

Yes, this actually works. There are 10k pulldowns on all inputs so that they won’t pick up on noise. Apply logic high signals to all inputs to test it.

I made this board just for fun. Perhaps it would make for a good SMD soldering challenge… I gave one to a Digital Electronics professor who was retiring and he loved it.

BOM

• U1-U5: 74AHCT08 SOIC-14 (or similar logic family)
• U6: 74LVC2G17 SOT-23-6
• D1: B340A Schottky Diode SMA
• PWR LED: 0805 SMD (color of your choice)
• HIGH and LOW LEDs: 1206 SMD (colors of your choice)
• R1-R3: 330 ohm 0603
• Pulldown resistors (back side): 20x 10k ohm 0603
• C1-C6: 100 nF 0603
• C7: 10 uF 1206 SMD 10V (or substitute with ceramic cap)
• 2 Pin Headers: 1x2 0.1" standard header pins
• 40 pin Header: 2x20 0.1" standard header pins

Eagle Files

https://github.com/SyncChannel/20-Input-AND-Gate

Modified version of the “VGA Blinking Lights” PBC by Danjovic:

https://github.com/Danjovic/VGA_Blinken

https://hackaday.io/project/8537-vga-blinking-lights

This version of the PCB has SMD passives to save space, but adds an onboard DB-15 connector for easy connection to a monitor. The PIC microcontroller is still DIP and socketed to allow for external programming.

See the original project page for the parts values, firmware, etc. The passives on this version are 0603. The DB-15 footprint is for a standard through-hole, right angle connector (Amphenol FCI ICD15S13E6GV00LF or similar).

It’s no longer 1" square, but it’s a lot easier to hook up that monitor with the onboard connector!

Eagle files shared on Github:

https://github.com/SyncChannel/VGA_Blinken_Modified

Original version of the PCB on OSH Park:

https://oshpark.com/shared_projects/BGKXsEzu

All credit goes to Danjovic, the original creator. This is an awesome project.

Through-hole resistor breakout board. The large resistor footprint accepts up to a 1 Watt resistor. The 2-pin header accepts standard 0.1" breakaway header pins.

Much OSH Park, don’t you think?

Very inspiration: https://oshpark.com/shared_projects/YyIz7BEX

Many blogs: http://syncchannel.blogspot.com

http://syncchannel.blogspot.com/2016/07/atmel-retrokit-sam-d-edition.html

http://syncchannel.blogspot.com/2016/06/lorawan-featherwing-for-adafruit-feather.html