Repurposing an old laptop power supply (18vdc) and dozens (actually - hundreds...) of white LEDs from old solar powered Christmas lights, to build an illuminated 'Merry Christmas' sign (a la Big Clive's Arcade sign).
The LEDs are made into strings of 5, each with a current limiting resistor, and a switching transistor to control the string. The transistors are switched from the outputs of multip...
12V 50Ω solenoid driver. Can be chained to control more than eight solenoids.
The solenoid driver uses a shift register with a latch to control its outputs such that a singe microcontroller (e.g. Arduino) can control large amounts of solenoids whilst only requiring 3 output pins.
- Too big thermals reliefs on; U1-pin8, R12..R15, R24..R27 (they cool too quickly while solder...
Schematics for a robot control system that uses a Raspberry Pi Zero, an Arduino Pro Mini, some voltage regulators, some motor controllers, and a rat's nest of wire.
These shift registers connect to the Arduino and help control the motors.
Four Dot Matrix displays with Red/Green dots connected together. Data is sent for example from Commodore 64 (C64) and stored in shift registers which drive LEDs, meanwhile next line is loaded.
This design should be able to connect three boards together and fill at once with six data lines, and two clock lines. Therefore 8bit Commodore 64 is enough to handle it.
This is first version, REV 1.0, my f...