max6955 connection how to?

[jayanth.devarayanadurga]

Can somebody explain what is the connection scheme looking at the table attached. I need to use 8 X 16-Segment displays to display a string like "230.2635 V". The connection scheme is confusing.

 

[tpetar]

Quick-Start: Driving 16-Segment Displays with the MAX6954
http://www.maximintegrated.com/app-notes/index.mvp/id/3212

Quick-Start: Driving 14-Segment Displays with the MAX6954
http://www.maximintegrated.com/app-notes/index.mvp/id/3211



MAX6954/MAX6955 Connection Scheme Tool
http://www.maximintegrated.com/design/tools/calculators/product-design/an1131.cfm


MAX6955 datasheet
http://datasheets.maximintegrated.com/en/ds/MAX6955.pdf
http://www.maximintegrated.com/datasheet/index.mvp/id/3540/t/al



Typical connections:
http://www.dz863.com/circuits-36-813660063-MAX6955_Typical-Operating-Circuits-Application-Circuit/

 

[jayanth.devarayanadurga]

How to use the table tpetar. It shows Digit 0 to 7 in the table. What does it mean? For Digit 0 it shows some connection where O1 is not used. What does Digit 0 and Digit7 etc mean in the table. I need to use 8 X 16-Segments to display 230.1426 V. See image. See the Connection schemes. It shows Digit 0 and 1. What does it mean? I don't understand that. It shows two connection schemes for my settings.

Edit: Now I came to know how to use the connection Scheme using table below. I did a connection for Digit 0 but it is not working. See images below.

 

[jayanth.devarayanadurga]

See Table 4 and 5 here https://www.maximintegrated.com/app-notes/index.mvp/id/3212

What am I doing wrong in the code. I am trying to display "MAXIM-IC". It is not working. I am attching Project + Proteus files.

CCS C v4.140 C Code

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#include <main.h>
 
#define MAX6955BaseAddress 0b11000000 
  
#define reg_noOp 0x00 
#define reg_decodeMode 0x01 
#define reg_globalIntensity 0x02 
#define reg_scanLimit 0x03 
#define reg_configuration 0x04 
#define reg_displayTest 0x07 
#define reg_digitType 0x0C 
  
#define reg_intensity10 0x10 
#define reg_intensity32 0x11 
#define reg_intensity54 0x12 
#define reg_intensity76 0x13 
#define reg_intensity10a 0x14 
#define reg_intensity32a 0x15 
#define reg_intensity54a 0x16 
#define reg_intensity76a 0x17 
  
#define USE_GLOBAL 0x00 
#define USE_DISCRETE 0x40 
#define RUN 0x01 
#define SHUTDOWN 0x00 
  
#define reg_digit0 0x60 
#define reg_digit1 0x61 
#define reg_digit2 0x62 
#define reg_digit3 0x63 
#define reg_digit4 0x64 
#define reg_digit5 0x65 
#define reg_digit6 0x66 
#define reg_digit7 0x67 
#define reg_digit0a 0x68 
#define reg_digit1a 0x69 
#define reg_digit2a 0x6A 
#define reg_digit3a 0x6B 
#define reg_digit4a 0x6C 
#define reg_digit5a 0x6D 
#define reg_digit6a 0x6E 
#define reg_digit7a 0x6F 
  
void writeMAX6955(int8, int8, int8); 
void initMAX6955(int8); 
  
void writeMAX6955(int8 driver, int8 command, int8 data) 
{ 
   i2c_start(); 
   i2c_write(MAX6955BaseAddress + (driver<<1)); 
   i2c_write(command); 
   i2c_write(data); 
   i2c_stop(); 
} 
  
void initMAX6955(int8 driver) 
{ 
   writeMAX6955(driver, reg_decodeMode, 0x00); 
   writeMAX6955(driver, reg_scanLimit, 0x07); 
   writeMAX6955(driver, reg_configuration, (RUN|USE_DISCRETE)); 
   writeMAX6955(driver, reg_globalIntensity, 0x0F); 
   writeMAX6955(driver, reg_digitType, 0x00); 
   writeMAX6955(driver, reg_displayTest, 0x01); 
   delay_ms(1000); 
   writeMAX6955(driver, reg_displayTest, 0x00);
   writeMAX6955(driver, 0x04, 0x01);
} 
 
void main(){
 
   initMAX6955(0);
      
   while(1){
         writeMAX6955(0, 0x20, 0x4D);
         writeMAX6955(0, 0x21, 0x41);
         writeMAX6955(0, 0x22, 0x58);
         writeMAX6955(0, 0x23, 0x49);
         writeMAX6955(0, 0x24, 0x4D);
         writeMAX6955(0, 0x25, 0x2D);
         writeMAX6955(0, 0x26, 0x49);
         writeMAX6955(0, 0x27, 0x43);
        
   }
}

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main.h

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#include <16F877A.h>
#device *=16
#device adc=16
 
#FUSES NOWDT                    //No Watch Dog Timer
#FUSES HS                       //High speed Osc (> 4mhz for PCM/PCH) (>10mhz for PCD)
#FUSES NOBROWNOUT               //No brownout reset
 
#use delay(clock=8000000)
 
#use STANDARD_IO( A,B,C,D,E )
#use i2c(Master,Fast,sda=PIN_C4,scl=PIN_C3,force_hw)

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Edit: I got it working...

 

[jayanth.devarayanadurga]

Video of Simulation