I to everybody,
I have a Panda II board and I need to interface it with PS/2 barcode scanner.
I connect the right pin to VCC, Clock, Data and GND, but something is wrong because I read some data that is wrong.
Someone has any experience with it?
Where can I found some protocol specifications?
Thanks to all for support.
Not sure I gave seen PS/2 code for NETMF but I think it should be easy. Maybe show some code?
By the way, you can use USB barcode readers and it would be easier as far as software.
Welcome to the community.
Gus, thanks for the welcome.
I find the ps/2 schema on internet and I connect the ps/2 male connector’s pin like this:
1 - Data
2 - Not Implemented
3 - Ground
4 - Vcc (+5V)
5 - Clock
6 - Not Implemented
with panda I connect Data with pin D40 and clock to pin D20
The code is:
public static void Main()
{
// Blink board LED
InputPort clk = new InputPort((Cpu.Pin)FEZ_Pin.Digital.Di20, false, Port.ResistorMode.PullUp);
InputPort data = new InputPort((Cpu.Pin)FEZ_Pin.Digital.Di40, false, Port.ResistorMode.PullUp);
ArrayList al = new ArrayList();
while (true)
{
if (clk.Read() == false)
{
al.Clear();
for(int index=0;index<11;index++)
{
bool bit = data.Read();
al.Add(bit);
}
String s = "";
for (int i = 0; i < al.Count; i++)
{
s += al[i].ToString() + " ";
}
Debug.Print("Bits: " + s);
}
Thread.Sleep(1);
}
}
But the bit that I receved are not correct.
Have any ideas?
I try to replicate the Arduino’s ps2 library to netmf, but something is wrong.
The original code is here: Google Code Archive - Long-term storage for Google Code Project Hosting.
My code is this
public class PS2Manager
{
private Cpu.Pin _clockPin;
private Cpu.Pin _dataPin;
private const int CLKFULL = 40;
private const int CLKHALF = 20;
private const int TICKS_PER_MICROSECOND = 10;
private TristatePort _clockPort;
private TristatePort _dataPort;
public PS2Manager(Cpu.Pin data, Cpu.Pin clock)
{
_clockPin = clock;
_dataPin = data;
_clockPort = new TristatePort((Cpu.Pin)_clockPin, false, false, Port.ResistorMode.PullDown);
_dataPort = new TristatePort((Cpu.Pin)_dataPin, false, false, Port.ResistorMode.PullDown);
}
void gohi(TristatePort port)
{
makePinOutput(port);
port.Write(true);
}
void golo(TristatePort port)
{
makePinOutput(port);
port.Write(false);
}
void makePinOutput(TristatePort port)
{
if (port.Active == false)
port.Active = true;
}
void makePinInput(TristatePort port)
{
if (port.Active == true)
port.Active = false;
}
private void _delayMicrosecond(int mics)
{
long totTicks = mics * TICKS_PER_MICROSECOND;
long end = Microsoft.SPOT.Hardware.Utility.GetMachineTime().Ticks + mics;
while (Microsoft.SPOT.Hardware.Utility.GetMachineTime().Ticks < end)
{ }
}
public int read(out int value)
{
int data = 0x00;
int i;
int bit = 0x01;
int parity = 1;
makePinInput(_dataPort);
// wait for data line to go low
while (_dataPort.Read() == true) ;
makePinInput(_clockPort);
// wait for clock line to go high
while (_clockPort.Read() == false) ;
_delayMicrosecond(CLKHALF);
golo(_clockPort);
_delayMicrosecond(CLKFULL);
gohi(_clockPort);
_delayMicrosecond(CLKHALF);
for (i = 0; i < 8; i++)
{
makePinInput(_dataPort);
if (_dataPort.Read() == true) data |= bit;
bit = bit << 1;
_delayMicrosecond(CLKHALF);
golo(_clockPort);
_delayMicrosecond(CLKFULL);
gohi(_clockPort);
_delayMicrosecond(CLKHALF);
parity = parity ^ (data & 0x01);
}
// we do the delay at the end of the loop, so at this point we have
// already done the delay for the parity bit
// stop bit
_delayMicrosecond(CLKHALF);
golo(_clockPort);
_delayMicrosecond(CLKFULL);
gohi(_clockPort);
_delayMicrosecond(CLKHALF);
_delayMicrosecond(CLKHALF);
golo(_dataPort);
golo(_clockPort);
_delayMicrosecond(CLKFULL);
gohi(_clockPort);
_delayMicrosecond(CLKHALF);
gohi(_dataPort);
value = data;
return 0;
}
public int write(int data)
{
int i;
int parity = 1;
//Serial.print("sending ");
//Serial.println(data, HEX);
makePinInput(_clockPort);
makePinInput(_dataPort);
if (_clockPort.Read() == false) return -1;
if (_dataPort.Read() == false) return -2;
golo(_dataPort);
_delayMicrosecond(CLKHALF);
// device sends on falling clock
// start bit
golo(_clockPort);
_delayMicrosecond(CLKFULL);
gohi(_clockPort);
_delayMicrosecond(CLKHALF);
// data bits
for (i = 0; i < 8; i++)
{
if ((data & 0x01) == 0x01) gohi(_dataPort);
else golo(_dataPort);
_delayMicrosecond(CLKHALF);
golo(_clockPort);
_delayMicrosecond(CLKFULL);
gohi(_clockPort);
_delayMicrosecond(CLKHALF);
parity = parity ^ (data & 0x01);
data = data >> 1;
}
// parity bit
if (parity == 0x01) gohi(_dataPort);
else golo(_dataPort);
_delayMicrosecond(CLKHALF);
golo(_clockPort);
_delayMicrosecond(CLKFULL);
gohi(_clockPort);
_delayMicrosecond(CLKHALF);
// stop bit
gohi(_dataPort);
_delayMicrosecond(CLKHALF);
golo(_clockPort);
_delayMicrosecond(CLKFULL);
gohi(_clockPort);
_delayMicrosecond(CLKHALF);
_delayMicrosecond(50);
return 0;
}
}
The main code is:
PS2Manager ps2 = new PS2Manager((Cpu.Pin)FEZ_Pin.Digital.Di40, (Cpu.Pin)FEZ_Pin.Digital.Di20);
while (true)
{
int data = 0;
while (ps2.read(out data) != 0) ;
Debug.Print("New char:" + data.ToString());
Thread.Sleep(1);
}
I receved something but I think it is wrong.
Can someone help me?
thanks to everybody.
Hi,
did you manage to scan barcode correctly? If yes, modifications you did can be useful for us too, thanks.
Welcome to the forum.
original poster has not been on forum since last posting.
if you have a question, please start a new thread.