Despite Retina and 4K screens, 7x5 dot matrix displays live!
7x10 R click carries a pair of standard 7x5 red LED matrices capable of displaying highly readable ASCII characters.
Despite Retinas, 4K TVs, and 300+ DPI smartphone screens, simple dot matrix displays persist. We read bus and railway departure times, vending machine menus, sometimes even news and advertisements from them. It’s an easy to implement, flexible and straightforward way to quickly relay important messages, without any clutter.
7x10 R click gives you a dual-character display, four if you double up on a board with two adjacent mikroBUS sockets, such as clicker 2 or Flip & click. It’s enough space to display an entire novel if required – simply implement horizontal scrolling.
What drives the display are four different chips. A pair of serial-in parallel-out shift registers take the input from an MCU through the mikroBUS™ SPI interface. A Darlington transistor array amplifies the current enough for lighting up the LEDs.
Turning all LEDs on at the same time would of course consume too much power, so there’s also a Johnson counter IC, which does the LED multiplexing, turning LEDs on and off rapidly, so the human eye doesn’t notice.
All the human notices is that he’s late for his train/bus.