Simple Linux C Driver/Header for CFA-635
Hello,
I didn't like the bloated C++ example included with my 635 USB LCD so i hacked it apart for useable stuff and wrote a simple C header file you can include in projects that contains useful functions. Hope this is useful to someone.
Header File:
Sample program using said header:
Hello,
I didn't like the bloated C++ example included with my 635 USB LCD so i hacked it apart for useable stuff and wrote a simple C header file you can include in projects that contains useful functions. Hope this is useful to someone.
Header File:
Code:
/***********************************************************************************************
*** A bunch of handy functions for using Crystalfontz 635 serial LCD
*** Adapted by Adam Yergovich (ayergovich@yahoo.com) from code supplied by Crystalfontz
*** April 10th, 2008
***********************************************************************************************/
//Some defines for commands to use. I only included some i found useful.
#define COM_SET_CURSOR_POS 0x0B
#define COM_SET_CURSOR_STY 0x0C
#define COM_SET_CONTRAST 0x0D
#define COM_SET_BACKLIT 0x0E
#define COM_SEND_DATA 0x1F
#define COM_SET_GPIO 0x022
#define COM_STORE_STATE 0x04
#define COM_CLEAR 0x06
int handle = 0; //Handle for Serial Port
unsigned int rt_key = 0; //Key press counts
unsigned int lt_key = 0; //Only presses (not releases) used
unsigned int up_key = 0;
unsigned int dn_key = 0;
unsigned int ck_key = 0;
unsigned int xx_key = 0;
/*************************************************************************
*** Functions that may be handy for you
*************************************************************************/
/************************************************************************
*** This funtion is used by the packet handling functions to get the CRC
*** You probably don't need to use it externally but if so, pass it a
*** pointer to the array containing the command and the length. Seed
*** should be 0xFFFF if you're using it for the LCD.
*** Returns an unsigned long with the CRC, so you'll likely need to bit
*** shift the value to get it into a packet to send.
************************************************************************/
unsigned long get_crc(unsigned char *bufptr, unsigned long len, unsigned long seed);
//------------------------------------------------------------------------------
/************************************************************************
*** Used to initialize the serial port @115200 with the proper settings.
*** Pass it a pointer to the string containing the device name.
*** Returns zero on success.
************************************************************************/
int Serial_Init(char * devname);
//------------------------------------------------------------------------------
/************************************************************************
*** Sends a byte to the open serial port. Prints error message if fscked
************************************************************************/
void SendByte(unsigned char datum);
//------------------------------------------------------------------------------
/************************************************************************
*** Intelligent command sending. Issue command # from defines above
*** and data pointer as well as data length. This funtion will then call
*** receive packet to check for proper acknowlegement.
*** Returns -1 if failure, 0 on success.
*** Note that this function WILL update any button presses.
************************************************************************/
int send_command(unsigned char command, unsigned char *datum, int len);
//------------------------------------------------------------------------------
/************************************************************************
*** Checks buffer for packets intelligently. Reads data length from
*** stream and checks the CRC. Updates button presses if it is a
*** report packet. Stores the returned value in the char array
*** destination.
*** Returns -1 if packet is bad, 1 if received good report (button press)
*** and 0 if otherwise successful.
************************************************************************/
int receive_packet(unsigned char *destination);
//-----------------------------------------------------------------------------
//------------------------------------------------------------------------------
unsigned long get_crc(unsigned char *bufptr,unsigned long len,unsigned long seed)
{
//CRC lookup table to avoid bit-shifting loops.
static const unsigned long crcLookupTable[256] =
{0x00000,0x01189,0x02312,0x0329B,0x04624,0x057AD,0x06536,0x074BF,
0x08C48,0x09DC1,0x0AF5A,0x0BED3,0x0CA6C,0x0DBE5,0x0E97E,0x0F8F7,
0x01081,0x00108,0x03393,0x0221A,0x056A5,0x0472C,0x075B7,0x0643E,
0x09CC9,0x08D40,0x0BFDB,0x0AE52,0x0DAED,0x0CB64,0x0F9FF,0x0E876,
0x02102,0x0308B,0x00210,0x01399,0x06726,0x076AF,0x04434,0x055BD,
0x0AD4A,0x0BCC3,0x08E58,0x09FD1,0x0EB6E,0x0FAE7,0x0C87C,0x0D9F5,
0x03183,0x0200A,0x01291,0x00318,0x077A7,0x0662E,0x054B5,0x0453C,
0x0BDCB,0x0AC42,0x09ED9,0x08F50,0x0FBEF,0x0EA66,0x0D8FD,0x0C974,
0x04204,0x0538D,0x06116,0x0709F,0x00420,0x015A9,0x02732,0x036BB,
0x0CE4C,0x0DFC5,0x0ED5E,0x0FCD7,0x08868,0x099E1,0x0AB7A,0x0BAF3,
0x05285,0x0430C,0x07197,0x0601E,0x014A1,0x00528,0x037B3,0x0263A,
0x0DECD,0x0CF44,0x0FDDF,0x0EC56,0x098E9,0x08960,0x0BBFB,0x0AA72,
0x06306,0x0728F,0x04014,0x0519D,0x02522,0x034AB,0x00630,0x017B9,
0x0EF4E,0x0FEC7,0x0CC5C,0x0DDD5,0x0A96A,0x0B8E3,0x08A78,0x09BF1,
0x07387,0x0620E,0x05095,0x0411C,0x035A3,0x0242A,0x016B1,0x00738,
0x0FFCF,0x0EE46,0x0DCDD,0x0CD54,0x0B9EB,0x0A862,0x09AF9,0x08B70,
0x08408,0x09581,0x0A71A,0x0B693,0x0C22C,0x0D3A5,0x0E13E,0x0F0B7,
0x00840,0x019C9,0x02B52,0x03ADB,0x04E64,0x05FED,0x06D76,0x07CFF,
0x09489,0x08500,0x0B79B,0x0A612,0x0D2AD,0x0C324,0x0F1BF,0x0E036,
0x018C1,0x00948,0x03BD3,0x02A5A,0x05EE5,0x04F6C,0x07DF7,0x06C7E,
0x0A50A,0x0B483,0x08618,0x09791,0x0E32E,0x0F2A7,0x0C03C,0x0D1B5,
0x02942,0x038CB,0x00A50,0x01BD9,0x06F66,0x07EEF,0x04C74,0x05DFD,
0x0B58B,0x0A402,0x09699,0x08710,0x0F3AF,0x0E226,0x0D0BD,0x0C134,
0x039C3,0x0284A,0x01AD1,0x00B58,0x07FE7,0x06E6E,0x05CF5,0x04D7C,
0x0C60C,0x0D785,0x0E51E,0x0F497,0x08028,0x091A1,0x0A33A,0x0B2B3,
0x04A44,0x05BCD,0x06956,0x078DF,0x00C60,0x01DE9,0x02F72,0x03EFB,
0x0D68D,0x0C704,0x0F59F,0x0E416,0x090A9,0x08120,0x0B3BB,0x0A232,
0x05AC5,0x04B4C,0x079D7,0x0685E,0x01CE1,0x00D68,0x03FF3,0x02E7A,
0x0E70E,0x0F687,0x0C41C,0x0D595,0x0A12A,0x0B0A3,0x08238,0x093B1,
0x06B46,0x07ACF,0x04854,0x059DD,0x02D62,0x03CEB,0x00E70,0x01FF9,
0x0F78F,0x0E606,0x0D49D,0x0C514,0x0B1AB,0x0A022,0x092B9,0x08330,
0x07BC7,0x06A4E,0x058D5,0x0495C,0x03DE3,0x02C6A,0x01EF1,0x00F78};
//Initial CRC value is 0x0FFFF.
unsigned long newCrc;
newCrc=seed;
//This algorithim is based on the IrDA LAP example.
while(len--){
newCrc = (newCrc >> 8) ^ crcLookupTable[(newCrc ^ *bufptr++) & 0xff];
}
//Make this crc match the one's complement that is sent in the packet.
return(~newCrc);
}
int Serial_Init(char *devname)
{
int
brate = B115200;
struct
termios term;
unsigned char init[30];
//open device
handle = open(devname, O_RDWR | O_NOCTTY | O_NONBLOCK);
if(handle <= 0)
{
printf("Serial_Init:: Open() failed\n");
return(1);
}
//get device struct
if(tcgetattr(handle, &term) != 0)
{
printf("Serial_Init:: tcgetattr() failed\n");
return(3);
}
//input modes
term.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|INPCK|ISTRIP|INLCR|IGNCR|ICRNL
|IXON|IXOFF);
term.c_iflag |= IGNPAR;
//output modes
term.c_oflag &= ~(OPOST|ONLCR|OCRNL|ONOCR|ONLRET|OFILL
|OFDEL|NLDLY|CRDLY|TABDLY|BSDLY|VTDLY|FFDLY);
//control modes
term.c_cflag &= ~(CSIZE|PARENB|PARODD|HUPCL|CRTSCTS);
term.c_cflag |= CREAD|CS8|CSTOPB|CLOCAL;
//local modes
term.c_lflag &= ~(ISIG|ICANON|IEXTEN|ECHO);
term.c_lflag |= NOFLSH;
//set baud rate
cfsetospeed(&term, brate);
cfsetispeed(&term, brate);
//set new device settings
if(tcsetattr(handle, TCSANOW, &term) != 0)
{
printf("Serial_Init:: tcsetattr() failed\n");
return(4);
}
//ReceiveBufferHead=ReceiveBufferTail=0;
tcflush(handle, TCIOFLUSH);
printf("Serial_Init:: success\n");
return(0);
}
void SendByte(unsigned char datum)
{
unsigned int bytes_written;
bytes_written=0;
if(handle)
{
if((bytes_written=write(handle, &datum, 1)) != 1)
printf("SendByte(): system call \"write()\" return error.\n Asked for %d bytes to be written, but %d bytes reported as written.\n", 1, bytes_written);
}
else
printf("SendByte(): \"handle\" is null\n");
}
int send_command(unsigned char command, unsigned char *datum, int len){
unsigned char mes[30];
unsigned char res[30];
int i = 0;
unsigned long crc = 0;
mes[0] = command;
mes[1] = len;
for(i=0;i<len;i++){
mes[i+2] = *datum;
datum++;
}
crc = get_crc(mes,len+2,0xFFFF);
mes[len+2]=crc;
crc >>= 8;
mes[len+3]=crc;
SendByte(mes[0]);
SendByte(mes[1]);
for(i=0;i<len;i++){
SendByte(mes[i+2]);
}
SendByte(mes[len+2]);
SendByte(mes[len+3]);
usleep(250000); //time needed to check for packet
while(1){
i = receive_packet(res);
if(i == -1) return -1;
else if(i == 0) return 0;
}
}
int receive_packet(unsigned char * destination){
int i = 1;
int rerror = 0;
unsigned char len = 0;
unsigned long crc = 0;
unsigned char crc_low = 0;
unsigned char crc_hi = 0;
rerror = read(handle, destination, 1);
if(rerror == -1) return -1;
while(1){
if(read(handle,&destination[1],1) == 1) break;
rerror++;
if(rerror == -1) return -1;
}
rerror = 0;
for(len = 0;len < destination[1] + 2; len++)
while(1){
if(read(handle,&destination[len+2], 1) == 1) break;
rerror++;
if(rerror == -1) return -1;
}
rerror = 0;
crc = get_crc(destination, destination[1] + 2, 0xFFFF);
crc_low = crc;
crc >>= 8;
crc_hi = crc;
if((crc_hi != destination[destination[1]+3]) || (crc_low != destination[destination[1]+2])){
return -1;
}
if((destination[0] & 0xC0) == 0x80){ //Is this a report? If so update button presses if necessary
switch (destination[2]){
case 0x1:
up_key++;
break;
case 0x2:
dn_key++;
break;
case 0x3:
lt_key++;
break;
case 0x4:
rt_key++;
break;
case 0x5:
ck_key++;
break;
case 0x6:
xx_key++;
break;
}
return 1;
}
else if((destination[0] & 0xC0) == 0x40){ //Regular response
return 0;
}
else {
printf("packet has bad header\n");
return -1;
}
}
Code:
/***********************************************************************
*** Simple test program for the Crystalfonts 635 USB LCD
*** demonstrating the use of the LCD.h
*** Allows for control of the LEDs on front using button arrow keys.
*** Up/Down to switch LED and die color
*** Left/Right to add or delete to duty cycle
*** X key exits. Check does nothing.
*** Adam Yergovich (ayergovich@yahoo.com)
*** April 10, 2008
***********************************************************************/
#include <termios.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include "LCD.h"
int main(void){
unsigned char mes[30]; //Buffer for packets to send
int i = 0;
int die = 0; //Duty cycle for LEDs
int pos = 12; //Which LED we're on
Serial_Init("/dev/ttyUSB0");
memcpy(&mes[2], "Adam Test Program",17); //Fill data
mes[0] = 0; //First column
mes[1] = 1; //Second row
i = send_command(COM_CLEAR,0x00,0x00);
sleep(1);
i = send_command(COM_SEND_DATA,mes,19); //len = 17 + 2
sleep(1);
i = 0;
while(xx_key == 0){
mes[0] = pos;
mes[1] = die;
send_command(COM_SET_GPIO,mes,2);
if(up_key){
pos++;
if(pos == 13) pos =12;
send_command(COM_CLEAR,0x00,0x00);
mes[0] = 0;
mes[1] = ((((pos+1)/2) - 6) * -1); //Display in row next to LED
if(pos % 2 == 0){
memcpy(&mes[2],"RED DIE",7);
send_command(COM_SEND_DATA,mes,9);
}
else{
memcpy(&mes[2],"GRN DIE",7);
send_command(COM_SEND_DATA,mes,9);
}
up_key = 0;
}
if(dn_key){
pos--;
if(pos <= 5) pos =5;
send_command(COM_CLEAR,0x00,0x00);
mes[0] = 0;
mes[1] = ((((pos+1)/2) - 6) * -1);
if(pos % 2 == 0){
memcpy(&mes[2],"RED DIE",7);
send_command(COM_SEND_DATA,mes,9);
}
else{
memcpy(&mes[2],"GRN DIE",7);
send_command(COM_SEND_DATA,mes,9);
}
dn_key = 0;
}
if(rt_key){
die = die +10;
if(die >= 100) die = 100;
rt_key = 0;
}
if(lt_key){
die = die -10;
if(die <= 0) die = 0;
lt_key = 0;
}
}
return 0;
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