Questions tagged [max7219]

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

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LED Matrix creation using resistors & MAX7219

I've been attempting to create my own LED matrix, but now I've plugged it all together I'm getting some unexpected LED's lighting up, it seems some are getting power when they shouldn't (not very ...
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Max7219 segment drivers output voltage is lower than expected

I'm using a max 7219 to control 7 highside drivers (which provides power to two higher voltage common cathode displays). The components on my breadboard are connected according to this schematic: The ...
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How to interpret MAX7219 timing diagram?

I'm trying to connect this module to atmega32u4 (16 MHz): Everything seems mostly working, but I have a question: how much time is needed for the latch to take effect? I.e., is a delay needed between ...
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MAX7219, SPI capable/Timing question?

So I purchased a cheap Double-7-Segment display piece (specifically this one: https://www.amazon.com/dp/B01D0WSCJA) To do some tinkering with. I've messed around with it manually to make sure it ...
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7-Segment Drivers: How do they work/how to handle them?

So I know to drive a 7-segment display you need a TON of pins. However there are 7-segment display drivers (such as the MAX7219) that seem pretty popular. However I'm looking at the datasheet, and am ...
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Maximum MAX7219 wire length to LEDs?

I'm intending to make a multiplexed 128 LEDs 'ceiling light', which has LEDs randomly spread out over a 2 by 1 meter area. For this I need two MAX7219 ICs, so they can handle 64 LEDs each, where ...
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144 views

MAX7221 not always powering on

I have a MAX7221 SPI 7-seg. LED driver linked to an AVR168P microcontroller. Sometimes when powering on, everything works as expected. Other times the display blanks and remains blank. Other times ...