This 8 digit seven segment display module (HCMODU0082) is based upon the Maxim MAX7219 LED display driver. The module uses two standard 4 digit seven segment displays to display a total of 8 digits in RED with decimal point. A convenient input and output header allows additional modules to be daisy-chained and controlled with just just 3 digital IO pins. To panel mounting the module has 4 mounting holes and 4 brass pillars with screws are supplied.
The Maxim MAX7219 driver allows for each segment of up to 8 digits (with decimal point) to be controlled individually from a serial interface. An 8x8 static ram area stores each digit and multiplexing the display is handled automatically.
If you plan to use this module with an Arduino board we have written an exclusive library (HCMAX7219) than allows you to effortlessly display and scroll alphanumeric characters across one or more modules. This can be downloaded from the software section of our support forum here:
http://forum.hobbycomponents.com/viewforum.php?f=58
HOBBY COMPONENTS NOTES:
PLEASE NOTE WHEN CONNECTING MULTIPLE MODULES: The modules are fitted with a reverse polarity protection diode in series with the 5V (VCC) supply. This has the effect of reducing the voltage on the VCC output pin relative to the voltage applied to its VCC input pin. Therefore when daisy-chaining multiple modules you should either supply 5V to each module's VCC input pin separately, or short out the diode (D1) on each additional module.
Model number: HCMODU0082
Driver: Maxim MAX7921
Voltage: 4.0 - 5.5V
Max current: 180mA (all LEDs on)
Min current: <0.5mA (shutdown mode)
Length: 82.3mm
Width: 15.5mm
Height: 18mm (approx)
Display length: 60.5mm
Display width: 14.2mm
Code: Select all
/* FILE: HCMODU0082_Serial_7_Segment_Module_Example2
DATE: 19/03/15
VERSION: 0.2
REVISIONS:
12/03/15 Created version 0.1
19/03/15 Updated to work with V0.2 of the HCMAX7219 library
This is an example of how to use the Hobby Components serial 8 digit seven 7
segment display module (HCMODU0082). To use this example sketch you will
need to download and install the HCMAX7921 library available from the software
section of our support forum (forum.hobbycomponents.com) or on github:
(https://github.com/HobbyComponents)
The library assumes you are using one module. If you have more than one module
connected together then you will need to change the following line in the
libraries HCMAX7219.h header file to the number of drivers you have connected:
#define NUMBEROFDRIVERS 1 <- Change this number
PINOUT:
MODULE.....UNO/NANO.....MEGA
VCC........+5V..........+5V
GND........GND..........GND
DIN........11...........51
CS (LOAD)..10...........10
CLK........13...........52
You may copy, alter and reuse this code in any way you like, but please leave
reference to HobbyComponents.com in your comments if you redistribute this code.
This software may not be used directly for the purpose of promoting products that
directly compete with Hobby Components Ltd's own range of products.
THIS SOFTWARE IS PROVIDED "AS IS". HOBBY COMPONENTS MAKES NO WARRANTIES,
WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ACCURACY OR
LACK OF NEGLIGENCE. HOBBY COMPONENTS SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE
FOR ANY DAMAGES INCLUDING, BUT NOT LIMITED TO, SPECIAL, INCIDENTAL OR
CONSEQUENTIAL DAMAGES FOR ANY REASON WHATSOEVER. */
/* Include the HCMAX7219 and SPI library */
#include <HCMAX7219.h>
#include "SPI.h"
/* Set the LOAD (CS) digital pin number*/
#define LOAD 10
/* Create an instance of the library */
HCMAX7219 HCMAX7219(LOAD);
void setup()
{
HCMAX7219.Init();
}
/* Main program */
void loop()
{
byte Loopcounter;
byte Position;
/* SCROLL SOME TEXT 5 TIMES BEFORE MOVING ON */
for (Loopcounter = 0; Loopcounter <= 5; Loopcounter++)
{
/* We are scrolling 30 characters of text across the entire display */
for (Position = 0; Position <= DISPLAYBUFFERSIZE + 30; Position++)
{
/* Write the test to the output buffer at the position we require */
HCMAX7219.print7Seg("HCMAX7219 SCROLLING TEXT DEMO ",Position);
/* Send the output buffer to the display */
HCMAX7219.Refresh();
delay(200);
}
}
/* WE CAN ALSO DISPLAY INTEGER NUMBERS */
/* Clear the output buffer */
HCMAX7219.Clear();
/* Write some text and output it*/
HCMAX7219.print7Seg("INT NUM.",8);
HCMAX7219.Refresh();
delay(2000);
/* display an example of a negative integer number */
HCMAX7219.Clear();
HCMAX7219.print7Seg(-1234567,8);
HCMAX7219.Refresh();
delay(2000);
/* Clear the output buffer */
HCMAX7219.Clear();
/* Write some text and output it*/
HCMAX7219.print7Seg("WITH DP.",8);
HCMAX7219.Refresh();
delay(2000);
/* Show the DP in different places. Notice when the DP is at the
beginning the number is padded with a zero */
HCMAX7219.Clear();
for (Position = 1; Position <= 7; Position++)
{
HCMAX7219.print7Seg(-1234567,Position,8);
HCMAX7219.Refresh();
delay(1000);
}
}
HCMAX7921 Arduino library for above sketch is available for download from the software section of our support forum here:
http://forum.hobbycomponents.com/viewto ... =58&t=1794
Or from github here:
https://github.com/HobbyComponents/HCMAX7219
MAX7921 Datasheet: