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Topic: Cheap and simple 7 segment led 4 characters (Read 2 times) previous topic - next topic


Good day!

I need to use 4 character 7 segment for my project. Even with dynamic indication it takes too much pins and too much code. Is there any option to get controllable over serial or I2C (or anything else) 7 segment?

Can it be cheaper than 16x2 character display (less than $9)?

Jeff K

Jeff K - JKDevices.com - home of the MegaMini


My website: http://www.harryrabbit.co.uk/electronics/home.html Up and running now! (Feel free to look round!) :D



MAX7221, very easy to write to with SPI

Can control from 3 to 8 seven segment displays.
1 resistor sets max current, 16 levels selectable via software.

Request a sample, or purchase for $4.
Easy to wire up to common cathode 7-segment displays.
All segments wired in parallel, unique common cathode to each device.

Writing to its registers:

 //  MAX7221: write shutdown register  
 digitalWrite(SS,LOW);  // take the SS pin low to select the chip:
 SPI.transfer(SHUTDOWN_ADDRESS);  // select the Address,
 SPI.transfer(0x00);      // select the data, 0x00 = Outputs turned off
 digitalWrite(SS,HIGH);   // take the SS pin high to de-select the chip:
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.



This ready-made module should satisfy your needs. Comes in 4 colors. It's not the cheapest way to solve it, but the easiest.

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