internal static void TestPWMLow()
{
BBBPinManager.AddMappingPWM(BBBPin.P9_14);
BBBPinManager.ApplyPinSettings(RoverMain.ApplyDevTree);
PWMPortMM Port = new PWMPortMM(PWMPortEnum.PWM1_A);
Port.PeriodNS = 1000000;
Port.DutyPercent = 0;
Port.RunState = true;
while (true)
{
for (int i = 0; i < 100; i++)
{
Port.DutyPercent = i;
Thread.Sleep(10);
}
Port.DutyPercent = 100;
Thread.Sleep(50);
for (int i = 100; i > 0; i--)
{
Port.DutyPercent = i;
Thread.Sleep(10);
}
Port.DutyPercent = 0;
Thread.Sleep(50);
}
}
/// <summary> Prepares the PWM output for use. </summary>
private void Initialize()
{
PWMPortEnum Device = PWMBBB.PinToPWMID(this.Pins[0]);
// Final path will be: /sys/devices/platform/ocp/4830_000.epwmss/4830_200.pwm/pwm/pwmchip_/pwm_
// x x y z
// Where x refers to device #. dev 0 = 0, dev 1 = 2, dev 2 = 4.
// y is an arbitrary number.
// To me, it looks like this is assigned from 0 in steps of +2, in the order that the PWM devices were loaded into the device tree.
// Operationally, it seems to have no significance, and there only ever seems to be one in each *.epwmss/*.pwm/ folder.
// This is probably because at that point it is already narrowed to a single device (2 pins).
// z refers to output #. out A = 0, out B = 2.
// We need to write the pin number (z) into the "export" file, and a 1 into the "enable" file to prepare the pin for use.
// At that point, whatever needed to be set in memory is ready for BBBCSIO's PWMPortMM to take over and work.
// Why does Linux have to be so damn difficult with everything it does? :(
string Path = "/sys/devices/platform/ocp";
// Append the memory addresses.
byte ExportNum = 0;
switch (Device)
{
case PWMPortEnum.PWM0_A:
Path += "/48300000.epwmss/48300200.pwm/pwm/";
ExportNum = 0;
break;
case PWMPortEnum.PWM0_B:
Path += "/48300000.epwmss/48300200.pwm/pwm/";
ExportNum = 1;
break;
case PWMPortEnum.PWM1_A:
Path += "/48302000.epwmss/48302200.pwm/pwm/";
ExportNum = 0;
break;
case PWMPortEnum.PWM1_B:
Path += "/48302000.epwmss/48302200.pwm/pwm/";
ExportNum = 1;
break;
case PWMPortEnum.PWM2_A:
Path += "/48304000.epwmss/48304200.pwm/pwm/";
ExportNum = 0;
break;
case PWMPortEnum.PWM2_B:
Path += "/48304000.epwmss/48304200.pwm/pwm/";
ExportNum = 1;
break;
default: throw new Exception("Invalid PWM pin given.");
}
// Append the (arbitrary) pwmchip #, by using the first one we find.
string[] PWMChips = Directory.GetDirectories(Path);
Log.Output(Log.Severity.DEBUG, Log.Source.HARDWAREIO, "Attempting to find correct pwmchip number...");
bool FoundPWMChip = false;
foreach (string SubdirPath in PWMChips)
{
string Subdir = new DirectoryInfo(SubdirPath).Name;
if (Subdir.StartsWith("pwmchip"))
{
Path += Subdir;
FoundPWMChip = true;
Log.Output(Log.Severity.DEBUG, Log.Source.HARDWAREIO, "Found \"" + Subdir + "\", using.");
}
else
{
Log.Output(Log.Severity.DEBUG, Log.Source.HARDWAREIO, "Found \"" + Subdir + "\", no good.");
}
}
if (!FoundPWMChip)
{
throw new Exception("Could not find PWM chip number. Is your device tree set correctly?");
}
// Export and enable the pin.
if (!Directory.Exists(Path + "/pwm" + ExportNum))
{
StreamWriter Exporter = File.AppendText(Path + "/export");
Exporter.Write(ExportNum);
Exporter.Flush();
Exporter.Close();
}
Path += ("/pwm" + ExportNum);
StreamWriter Enabler = File.AppendText(Path + "/enable");
Enabler.Write("1");
Enabler.Flush();
Enabler.Close();
this.Port = new PWMPortMM(Device);
}
