Content for MAX7221


Serially Interfaced, 8-Digit, LED Display Drivers The MAX7219/MAX7221 are compact, serial input/output common-cathode display drivers that interface microprocessors (µPs) to 7-segment numeric LED displays of up to 8 digits, bar-graph displays, or 64 individual LEDs. Included on-chip are a BCD code-B decoder, multiplex scan circuitry, segment and digit drivers, and an 8x8 static RAM that stores each digit. Only one external resistor is required to set the segment current for all LEDs. The MAX7221 is compatible with SPI™, QSPI™, and MICROWIRE™, and has slew-rate-limited segment drivers to reduce EMI. A convenient 4-wire serial interface connects to all common µPs. Individual digits may be addressed and updated without rewriting the entire display. The MAX7219/MAX7221 also allow the user to select code-B decoding or no-decode for each digit.

A high current power supply built around a server voltage regulator

“Regular readers of this blog will have already seen the article that I published about 4 months ago where I attempted to reverse engineer a voltage regulator module originally designed to fit into a Dell server. The theory was that …

Interactive Arduino Powered Coffee Table

“One quick fore note: this is my first Instructable and my first large Arduino project, so if you see any stupid errors or have an idea of how things could be done better, then please let me know. Now that …

Prototype 14-segment-display shield

“There are many ways (*) to drive the 6-digit 14-segment common cathode display from Seeed Studio. This time I chose to multiplex two MAX7221, a method described here (but used for driving a bi-color 8x8 LED matrix).”