The New Hotness

The button definition table now includes a string that becomes the button’s command to the sewing machine motor controller:

#define MAXCMDLEN 2

enum bstatus_t {BT_DISABLED,BT_UP,BT_DOWN};

typedef void (*pBtnFn)(byte BID);		// button action function called when hit

struct button_t {
	byte ID;					// button identifier, 0 unused
	byte Group;					// radio button group, 0 for none
	byte Status;				// button status
	word ulX,ulY;				// origin: upper left
	word szX,szY;				// button image size
	pBtnFn pAction;				// button function
	char Cmd[MAXCMDLEN + 1];	// command string
	char NameStem[9];			// button BMP file name - stem only
};

struct button_t Buttons[] = {
	{ 1,	1, BT_UP,		  0,0,		 80,80,	DefaultAction,	"Nu",	"NdUp"},
	{ 2,	1, BT_UP,		  0,80,		 80,80,	DefaultAction,	"Na",	"NdAny"},
	{ 3,	1, BT_DOWN,		  0,160,	 80,80,	DefaultAction,	"Nd",	"NdDn"},

	{ 4,	2, BT_DOWN,		 80,0,		120,80,	DefaultAction,	"Pr",	"PdRun"},
	{ 5,	2, BT_UP,		 80,80,		120,80,	DefaultAction,	"P1",	"PdOne"},
	{ 6,	2, BT_UP,		 80,160,	120,80,	DefaultAction,	"Pf",	"PdFol"},

	{ 7,	3, BT_DOWN,		200,0,		 80,80,	DefaultAction,	"Sh",	"SpMax"},
	{ 8,	3, BT_UP,		200,80,		 80,80,	DefaultAction,	"Sm",	"SpMed"},
	{ 9,	3, BT_UP,		200,160,	 80,80,	DefaultAction,	"Sl",	"SpLow"},

//	{10,	0, BT_UP,	311,0,		  8,8,	CountColor,	'\0',	'\0',	"Res"}
};

byte NumButtons = sizeof(Buttons) / sizeof(struct button_t);

The default button handler now sends the button’s command string whenever it finds the button down after all the processing:

#define TRACEACTION false

void DefaultAction(byte BID) {

byte i,BX;
byte Group;

	if (!BID) {											// not a valid ID
		printf("** Button ID zero in DefaultAction\r\n");
		return;
	}

	BX = FindButtonIndex(BID);
	if (BX == NumButtons) {								// no button for that ID
//		printf("** No table entry for ID: %d\r\n",BID);
		return;
	}

#if TRACEACTION
	printf("Default action: BID %d St %d -- ",BID,Buttons[BX].Status);
#endif

	if (Buttons[BX].Status == BT_DISABLED) {		// cannot do anything to disabled buttons
#if TRACEACTION
		printf("disabled\r\n");
#endif
		return;
	}

	Group = Buttons[BX].Group;

	if (Group) {									// member of group?
		if (Buttons[BX].Status == BT_DOWN) {		//  if down, remain that way
#if TRACEACTION
			printf("already down\r\n");
#endif
		}
		else {										//  is up
			for (i=0; i<NumButtons; i++) {			//   so unpush other buttons in group
				if ((Buttons[i].Group == Group) && (Buttons[i].Status == BT_DOWN) && (i != BX)) {
#if TRACEACTION
					printf("release ID %d - ",Buttons[i].ID);
#endif
					Buttons[i].Status = BT_UP;
					DrawButton(Buttons[i].ID,Buttons[i].Status);
				}
			}
#if TRACEACTION
			printf("push\r\n");
#endif
			Buttons[BX].Status = BT_DOWN;			//   and push this button down
		}
	}
	else {											// not a group, so just toggle
#if TRACEACTION
		printf("toggle\r\n");
#endif
		Buttons[BX].Status = (Buttons[BX].Status == BT_DOWN) ? BT_UP : BT_DOWN;
	}

	DrawButton(BID,Buttons[BX].Status);

	if (Buttons[BX].Status == BT_DOWN) {			// is this button now (or still) pressed?
		SendCmd(Buttons[BX].Cmd);
	}

}

That means the controller will see identical commands each time the button gets pressed, which doesn’t have any downsides. You could build an increment / decrement speed function without much trouble, although there’s still no way to display any returned values on the LCD.

Working under the possibly unwarranted assumption that serial communications between the two Arduinos won’t encounter any errors, I just wrap the command string in a distinctive marker and send it off:

void SendCmd(char *pCmd) {

char Msg[MAXCMDLEN + 3];

	strcpy(Msg,"[");
	strcat(Msg,pCmd);
	strcat(Msg,"]");

	Serial.print("Cmd: ");							// copy to console
	Serial.println(Msg);

	Serial1.println(Msg);							// send command!

}

The Serial1 port runs at a nose-pickin’ 9600 baud, because the motor controller often gets wrapped up in what it’s doing. On the other paw, when the controller gets distracted, the operator will be feeding fabric past the needle at a pretty good clip and won’t have a finger to spare for the UI buttons, so it would probably work no matter what.

That mismatch, however, allows the motor controller to babble on at length, without overruning the UI’s console output. This routine collects lines from the controller:

char GetStatLine(void) {

static byte Index = 0;
char NewChar;

	if (!Serial1.available()) {					// return if no chars in queue
		return 0;
	}

	do {
		NewChar = Serial1.read();
		switch (NewChar) {
		case '\r':								// end-of-line on CR
			MCtlBuffer[Index] = 0;
			Index = 0;
			return strlen(MCtlBuffer);			// return from mid-loop
			break;								//  unnecessary
		case '\n':								// discard NL
			break;
		default:
			MCtlBuffer[Index] = NewChar;		// store all others
			Index += (Index < STATMAXLEN) ? 1 : 0;
		}
	} while (Serial1.available());

	return 0;

}

A call in the main loop dumps each line after the terminating CR:

char GetStatLine(void) {

static byte Index = 0;
char NewChar;

	if (!Serial1.available()) {					// return if no chars in queue
		return 0;
	}

	do {
		NewChar = Serial1.read();
		switch (NewChar) {
		case '\r':								// end-of-line on CR
			MCtlBuffer[Index] = 0;
			Index = 0;
			return strlen(MCtlBuffer);			// return from mid-loop
			break;								//  unnecessary
		case '\n':								// discard NL
			break;
		default:
			MCtlBuffer[Index] = NewChar;		// store all others
			Index += (Index < STATMAXLEN) ? 1 : 0;
		}
	} while (Serial1.available());

	return 0;

}

Which produces output like this:

Kenmore Model 158 User Interface
 Compiled: Jan 26 2015 at 15:33:52
Ed Nisley - KE4ZNU
TS... OK
SD... OK
LCD... should be active
Cmd: [Nd]
Cmd: [Pr]
Cmd: [Sh]
MC |** Bad command string: [--]
MC |  540, 65535,   194
MC |  610,     0,   194
MC |  783,    55,   236
MC | 1262,    84,   391
MC | 1452,   116,   394
MC | 1633,   123,   394
MC | 1494,   132,   405
MC | 1768,   126,   406
MC | 1488,   126,   406
MC | 1425,   137,   406
MC | 1517,   132,   406
MC | 1461,   126,   209
MC |Coast: 1099
MC |Parking Stop down: Done
MC | stopped

The “bad command string” isn’t actually an error. The first outbound line consists of [--] and a carriage return, which isn’t a valid command, just to make sure that the motor controller’s incoming serial port buffer doesn’t contain any junk. Obviously, I should add that string to the command decoder…

The New Hotness

Kenmore 158 UI: Button Commands