Electrical and embedded device designer Peter Hill has a business card that you'll probably want to keep handy.
The card is a plain circuit board without any components, making it flat enough to fit in a wallet or business card holder. The silkscreen and copper layers contain contact information about its creator.
The main part of the board consists of 0.1-inch through-holes arranged like a breadboard into which various components can be installed. On the top and bottom there are power rails again like on a breadboard and a place to mount a USB Type-C or USB Micro-B port for power. If desired, the board can be connected to an external power supply.
There are places to install decoupling capacitors, mounting holes and even places to install conventional integrated circuits (ICs): pads for an operational amplifier in SOIC-8 package, SOT-23 linear regulator and oscillator.
The main part of the board consists of 0.1-inch through-holes arranged like a breadboard into which various components can be installed. On the top and bottom there are power rails again like on a breadboard and a place to mount a USB Type-C or USB Micro-B port for power. If desired, the board can be connected to an external power supply.
There are places to install decoupling capacitors, mounting holes and even places to install conventional integrated circuits (ICs): pads for an operational amplifier in SOIC-8 package, SOT-23 linear regulator and oscillator.