Erfarenheter av Phidget för Raspberry Pi.

Innehåll.

Tillbaka till Raspbery Pi
Inledning.
Inkoppling.
Installation.
Program.
Referenser.

Inledning.

Här beskrivs hur man kan använda Phidgets TextLCD.
En nackdel med TexLCD är att texten är mycket svag. Jag har inte lyckats komma på hur man ska få texten starkare eller bakgrundsbelyst.
Tydligen ska man använda kommandot:
CPhidgetTextLCD_setBrightness(txt_lcd, 1);
Värdet 1 kan vara mellan 0 och 100.
1 tänder bakgrundsbelysningen. 0 släcker bakgrundsbelysningen.

Till början.

Inkoppling.

Phidget TextLCD ansluts till Raspberry Pi via USB.

Installation.

Följande program behöver installeras:

libphidget-2.1.8.20151217.tar.gz
phidget21-c-examples-2.1.8.20151217.tar.gz
libusb-1.0-0-dev

Programmen kan hämtas här:
wget http://www.phidgets.com/downloads/examples/phidget21-c-examples_2.1.8.20151217.tar.gz
wget http://www.phidgets.com/downloads/libraries/libphidget.tar.gz

Packa upp programmen på följande sätt:
tar -zxvf libraries/libphidget.tar.gz
tar -zxvf phidget21-c-examples-2.1.8.20151217.tar.gz

Programpaketen kan laddas ner här:

libusb-1.0-0-dev får installeras från ordinarie paketförråd. För Raspberry Pi sker installationen med kommando:
sudo apt-get install libusb-1.0-0-dev

Efter nedladdning ska paketen installeras,

libpidget21 med kommandona:
./configure; make; make install

phidget21-c-examples med kommandona:
./configure; make


För att kunna skriva C-program med MySQL behövs förutom installation av paketen till MySQL även libmysqlclient-dev:
sudo apt-get install libmysqlclient-dev

Till början.

Program.

Detta program är en modifierad kopia av filen TextLCD-simple i Phidgets exampel.
Programmet, pi-textlcd.c, fungerar både på PC och Raspberry Pi.

/******************************************************************/ // This simple example set up a TextLCD(including the TextLCD Adapter), waits for one to be attached, and then simulates // the different functionalites available on the TextLCD // // Copyright 2012 Phidgets Inc. All rights reserved. // This work is licensed under the Creative Commons Attribution 2.5 Canada License. // view a copy of this license, visit http://creativecommons.org/licenses/by/2.5/ca/ // // Kompilera: gcc pi-textlcd.c -o pi-textlcd -lphidget21 /*******************************************************************/ #include <stdio.h> #include <phidget21.h> int CCONV AttachHandler(CPhidgetHandle TXT, void *userptr) { int serialNo; const char *name; CPhidget_getDeviceName (TXT, &name); CPhidget_getSerialNumber(TXT, &serialNo); printf("%s %10d attached!\n", name, serialNo); return 0; } int CCONV DetachHandler(CPhidgetHandle TXT, void *userptr) { int serialNo; const char *name; CPhidget_getDeviceName (TXT, &name); CPhidget_getSerialNumber(TXT, &serialNo); printf("%s %10d detached!\n", name, serialNo); return 0; } int CCONV ErrorHandler(CPhidgetHandle TXT, void *userptr, int ErrorCode, const char *Description) { printf("Error handled. %d - %s\n", ErrorCode, Description); return 0; } //Display the properties of the attached phidget to the screen. We will be displaying the name, serial number and version of the attached device. int display_properties(CPhidgetTextLCDHandle phid) { int serialNo, version, numRows, numColumns, backlight, cursor, contrast, cursor_blink, numScreens; const char* ptr; CPhidget_DeviceID id; CPhidget_getDeviceType((CPhidgetHandle)phid, &ptr); CPhidget_getSerialNumber((CPhidgetHandle)phid, &serialNo); CPhidget_getDeviceVersion((CPhidgetHandle)phid, &version); CPhidget_getDeviceID((CPhidgetHandle)phid, &id); CPhidgetTextLCD_getRowCount (phid, &numRows); CPhidgetTextLCD_getColumnCount (phid, &numColumns); CPhidgetTextLCD_getBacklight (phid, &backlight); CPhidgetTextLCD_getContrast (phid, &contrast); CPhidgetTextLCD_getCursorOn (phid, &cursor); CPhidgetTextLCD_getCursorBlink (phid, &cursor_blink); printf("%s\n", ptr); printf("Serial Number: %10d\nVersion: %8d\n", serialNo, version); if(id == PHIDID_TEXTLCD_ADAPTER){ CPhidgetTextLCD_getScreenCount (phid, &numScreens); printf("# Screens: %d\n", numScreens); CPhidgetTextLCD_setScreen(phid, 0); CPhidgetTextLCD_setScreenSize(phid, PHIDGET_TEXTLCD_SCREEN_2x16); CPhidgetTextLCD_initialize(phid); //CPhidgetTextLCD_setBacklight(phid, 1); //Jan P } printf("# Rows: %d\n# Columns: %d\n", numRows, numColumns); printf("Current Contrast Level: %d\nBacklight Status: %d\n", contrast, backlight); printf("Cursor Status: %d\nCursor Blink Status: %d\n", cursor, cursor_blink); return 0; } int textlcd_simple() { int result; const char *err; //Declare an TextLCD handle CPhidgetTextLCDHandle txt_lcd = 0; //create the TextLCD object CPhidgetTextLCD_create(&txt_lcd); //Set the handlers to be run when the device is plugged in or opened from software, unplugged or closed from software, or generates an error. CPhidget_set_OnAttach_Handler((CPhidgetHandle)txt_lcd, AttachHandler, NULL); CPhidget_set_OnDetach_Handler((CPhidgetHandle)txt_lcd, DetachHandler, NULL); CPhidget_set_OnError_Handler((CPhidgetHandle)txt_lcd, ErrorHandler, NULL); //open the TextLCD for device connections CPhidget_open((CPhidgetHandle)txt_lcd, -1); //get the program to wait for an TextLCD device to be attached printf("Waiting for TextLCD to be attached....\n"); if((result = CPhidget_waitForAttachment((CPhidgetHandle)txt_lcd, 10000))) { CPhidget_getErrorDescription(result, &err); printf("Problem waiting for attachment: %s\n", err); return 0; } //Display the properties of the attached textlcd device display_properties(txt_lcd); //read TextLCD event data printf("Reading.....\n"); //Begin simulation of capabilities //Jan Pihlgren printf("Turn bascklight on. Press any key to continue\n"); getchar(); CPhidgetTextLCD_setBacklight(txt_lcd, 1); // Jan P. Tänder backgrundsbelysningen. //Step 1: Write a simple message to the first row printf("Writing to first row. Press any key to continue\n"); getchar(); CPhidgetTextLCD_setDisplayString (txt_lcd, 0, "Row 1"); //Step 2: write a simple message to the second row printf("Writing to second row. Press any key to continue\n"); getchar(); CPhidgetTextLCD_setDisplayString (txt_lcd, 1, "Row 2"); //Step 3: turn up, turn down, and set back to default the contrast printf("Adjusting contrast up. Press any key to continue\n"); getchar(); CPhidgetTextLCD_setContrast (txt_lcd, 255); //valid range is 0 - 255, default is 0 normal viewable seems to be around 100 //CPhidgetTextLCD_setContrast (txt_lcd, 100); printf("Restoring default contrast. Press any key to continue\n"); getchar(); CPhidgetTextLCD_setContrast (txt_lcd, 110); //Step 4: Turn on the cursor printf("Turn on cursor. Press any key to continue\n"); getchar(); CPhidgetTextLCD_setCursorOn (txt_lcd, 1); //Step 5: turn on the cursor blink printf("Turn on cursor blink. Press any key to continue\n"); getchar(); CPhidgetTextLCD_setCursorOn (txt_lcd, 0); CPhidgetTextLCD_setCursorBlink (txt_lcd, 1); //End simulation printf("Press any key to end\n"); getchar(); CPhidgetTextLCD_setCursorBlink (txt_lcd, 0); CPhidgetTextLCD_setDisplayString (txt_lcd, 0, ""); CPhidgetTextLCD_setDisplayString (txt_lcd, 1, ""); //since user input has been read, this is a signal to terminate the program so we will close the phidget and delete the object we created printf("Closing...\n"); CPhidgetTextLCD_setBrightness(txt_lcd, 0); // Jan P. Släcker bakgrundsbelysningen. CPhidget_close((CPhidgetHandle)txt_lcd); CPhidget_delete((CPhidgetHandle)txt_lcd); //all done, exit return 0; } int main(int argc, char* argv[]) { textlcd_simple(); return 0; }

Kompilera med kommando:
gcc pi-textlcd.c -o pi-textlcd -lphidget21

Kör programmet med:
sudo ./pi-textlcd

Referenser.

Phidget.
4 Projects You Can Do With Raspberry Pi and Phidgets

Till början.