Connecting Waveshare LCD1602 RGB to Raspberry using C#

Question

I am trying to connect LCD1602 RBG Waveshare to the Raspberry using C#. I connected it to the Raspberry and set the permissions, now trying to pass some data. The code below run all lines, but the LCD is not reacting. If anyone can advise me.

using System;
using System.Device.Gpio;
using System.Threading.Tasks;
using System.Device.I2c;
using Iot.Device.CharacterLcd;
using Iot.Device.Pcx857x;
using System.Threading;

namespace pi_project
{
    public class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Test1");

            using I2cDevice i2c = I2cDevice.Create(new I2cConnectionSettings(1, 0x3e));
            //BCM2835
            using var driver = new Pcf8574(i2c);
            using var lcd = new Lcd1602(registerSelectPin: 0,
                                    enablePin: 2,
                                    dataPins: new int[] { 4, 5, 6, 7 },
                                    backlightPin: 3,
                                    backlightBrightness: 0.3f,
                                    readWritePin: 1,
                                    controller: new GpioController(PinNumberingScheme.Logical, driver));
            int counter = 0;

            while (counter <= 4)
            {
                lcd.Clear();

                lcd.SetCursorPosition(0, 0);
                lcd.Write("TestText1");

                lcd.SetCursorPosition(0, 1);
                lcd.Write("TestText2");

                Thread.Sleep(2000);
                counter++;
            }
        }
    }
}

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: 20 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- 3c -- 3e --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: 60 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: 70 -- -- -- -- -- -- --

The code looks about right, if it's wired correctly. Do you have a link to the schematic you are using? — PMF, Dec 30 '21 at 21:26
Something is wrong with your wiring. The LCD has I2C addresses 0x7c and 0xc0, which are not visible in your i2cdetect output, but many others are. Please first make sure you see these two devices on your bus. — PMF, Jan 01 '22 at 09:56
That does not match up with the documentation I have found. Can you confirm the python example from https://www.waveshare.com/wiki/LCD1602_RGB_Module works? — PMF, Jan 01 '22 at 15:25

score 1 · Accepted Answer · answered Jan 01 '22 at 18:49

The controller for these displays is normally a HD44780 or compatible. If the python sample works fine, then this should do:

var i2cLcdDevice = I2cDevice.Create(new I2cConnectionSettings(busId: 1, deviceAddress: 0x3E));
var i2cRgbDevice = I2cDevice.Create(new I2cConnectionSettings(busId: 1, deviceAddress: 0x60));
using LcdRgb lcd = new LcdRgb(new Size(16, 2), i2cLcdDevice, i2cRgbDevice);
{
    lcd.Write("Hello World!");
    lcd.SetBacklightColor(Color.Azure);
}

(for reasons beyond me, the python sample defines the addresses as 0x7c >> 1 and 0xc0 >> 1, which are 0x3E and 0x60, which aligns with your device scan)

Connecting Waveshare LCD1602 RGB to Raspberry using C#

1 Answers1