Count Me

This allows you to control 8 7-segment displays via shift registers with only 3 wires from your microcontroller of choice.


7 Segment LED Displays are great for any application needing alphanumeric feedback/information - but connecting to them, and getting them to work can lead to way too many wires going in way too many directions.



Kit Parts:
  • Tymkrs Count Me v1 board
  • 3x 74HC595 Shift Register (serial in, parallel out)
  • 2x 1x8pin female headers with labels for connections
  • 4x 1x2pin male headers for easy mounting on a breadboard
  • 2x Set of 4 7 segment led displays
  • R1-R3: 3x 1k ohm resistors
  • R4-R19: 16x 100 ohm resistors
  • Not pictured: 3 sockets for the 595′s!
Build Notes:
  • 74HC595 Shift Register (serial in parallel out): Remember to note where the notch is on the front so your pins are in the right direction!
  • 2x 1x8pin female headers with labels for connections: These are female headers and thus makes it easy to use breadboard wires to hook it to your system.
  • 2x Set of 4 7 segment led displays: The dots of the segments go towards the chips (bottom of the board).
  • R1-R3 (1k ohm resistors): These are pull-down resistors
  • R4-R19 (100 ohm resistors): These are current limiting resistors for the led segments
  • If you choose to chain, the top three segments allow for “pass through”
  • We have tested this successfully with 3.3v and 5v.
Example Set-up:



Demo Code: http://tymkrs.com/code/CountMe_Simple_74HC595_Demo.spin

Driver OBJ: http://obex.parallax.com/object/102

Assembly Video:



New to using 7 segment LED displays? Not sure how to use them?

http://tymkrs.tumblr.com/post/54105338290/tymkrs-count-me-7-segment-led-display-kit