I try to drive a 4 digit display: it is a grove one driven by TM1637 unit.
Device has two pins:
[ul]a data one which is an output but an input too.
a clock one. No problem with it.
[/ul]
Data pin is used to send command and to receive ACK signal. My problem is with reading ACK signal: I’ve try with an tristate port which seems to be adequat, but Nothing happen. The while loop read infinitely:
Code which use driver:
public class Program
{
public static void Main()
{
ProgramSetup();
while (true)
{
}
}
private static void ProgramSetup()
{
Debug.Print(Resources.GetString(Resources.StringResources.String1));
Led led = new Led(GHI.Pins.FEZPandaIII.Gpio.D5);
led.Blink(200, 500);
Digit4Display digit4=new Digit4Display(GHI.Pins.FEZPandaIII.Gpio.D3,FEZPandaIII.Gpio.D2);
digit4.Display(0x1,0x08);
Thread.Sleep(5000);
led.StopBlink();
}
}
Code of driver:
public class Digit4Display
{
private OutputPort _clkPin;
private TristatePort _dataPin;
private byte[] TubeTab = { 0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f };
public Digit4Display(Cpu.Pin dataPin, Cpu.Pin clkPin)
{
_dataPin = new TristatePort(dataPin, false,false,Port.ResistorMode.Disabled);
_clkPin = new OutputPort(clkPin, false);
Init();
}
private void _dataPin_OnInterrupt(uint data1, uint data2, DateTime time)
{
}
private void SetDataOutput()
{
if (_dataPin.Active==false)
_dataPin.Active = true;
}
private void SetDataInput()
{
if (_dataPin.Active==true)
_dataPin.Active = false;
}
private void Init() // OK
{
SetDataOutput(); // Set as output
Clear();
}
public void Display(byte addr, byte data)
{
byte segData = Coding(data);
SendStartSignal();
WriteByte(0x44);
SendStopSignal();
SendStartSignal();
var v = addr | 0xc0;
WriteByte((byte)v);
WriteByte(segData);
SendStopSignal();
SendStartSignal();
WriteByte(0); // Command Display Control
SendStopSignal();
}
private byte Coding(byte data)
{
if (data == 0x7f) data = 0;
else data = TubeTab[data];
return data;
}
public void Clear() // OK
{
Display(0x00, 0x7f);
Display(0x01, 0x7f);
Display(0x02, 0x7f);
Display(0x03, 0x7f);
}
private void WriteByte(byte data)
{
int count=0;
int mask = 0x01;
for(int i = 0;i < 8;i++)
{
_clkPin.Write(false);
_dataPin.Write((data & mask) != 0);
data >>= 1;
_clkPin.Write(true);
}
_clkPin.Write(false);
_dataPin.Write(true);
_clkPin.Write(true);
SetDataInput();
var d = _dataPin.Read();
while (d)
{
count+=1;
if (count == 200)
{
SetDataOutput();
_dataPin.Write(false);
count = 0;
}
SetDataInput();
d = _dataPin.Read();
}
SetDataOutput();
}
private void SendStartSignal() // OK
{
SetDataOutput();
_clkPin.Write(true);
_dataPin.Write(true);
_dataPin.Write(false);
_clkPin.Write(false);
}
private void SendStopSignal() // OK
{
_clkPin.Write(false);
_dataPin.Write(false);
_clkPin.Write(true);
_dataPin.Write(true);
}
}
