7-Segment Number Display

Print Friendly, PDF & Email

4) Wire up the Circuit

  • Place the XBee adapter into the breadboard and wire up the power buses to each other. Next, connect the VCC terminal of the XBee adapter to the positive rail and the ground terminal to the negative rail.

  • We made it easier to attach the battery holder to the breadboard by soldering some male headers onto its positive and negative wiring leads.

  • Connect the battery pack directly to the ground and power rails.

  • Place the 7-segment display module across the trough in the breadboard as show, so that the two columns of pins go into separate breadboard rows. The display shown is a common-cathode model which means that all the LED segments share a command ground connecting. Attach one or both of the GND pins to the ground rail of the breadboard. For this module we use physical pin 12. You can either use a regular wire or a low-value resistor (~100 Ohm) to make the connection.

  • The remaining pins each run one segment of the numeric display.

  • Wire each one to a digital output on the XBee.
  • Here’s the connections for the 7-segment display that we used (great data sheet notes here). Yours may be different so check its data sheet and connect it accordingly!
XBee pin XBee physical Display pin Display physical
AD0 20 segment A 14
AD1 19 segment B 13
AD2 18 segment F 1
AD3 17 segment G 2
AD4 11 segment E 6
AD5 15 segment D 7
AD6 (RTS) 16 segment C 8
AD7 (CTS) 12 segment RDP 9
n/a [GND] common cathode 4
n/a [GND] common cathode 12

Note: The particular organization of the segments can be changed according to your taste.

  • And finally, insert the XBee into the breakout board and connect the battery pack. If there’s a switch on the battery pack be sure to switch it to the on position. All the segments should be off to start with. Now any pins brought high on the XBee, either remotely or from the Internet via XIG will turn on one of the segments. For example, to show the decimal number 5, turn on segments A, F, G, C and D! See  Setting or Getting Remote XBee AT Settings on the XIG for more information on remotely setting pins via iDigi.

  • Above is a breadboard layout and a diagram of the circuit for your reference.

Comments are closed.