CCS/TMDXIDDK379D: EnDat Example , trouble with GPIO24

Hi,

Is the encoder powered? Which encoder are you using?

Yes the encoder is powered.

I have an EQN 1337

I can measure at Group M12 on the board

Enc-Do 3.3 V

Tx-En 0V

Enc-Di 0V

PwrEn 3.3V

Hi,

This is part of the encoder initialization. This is how the encoder responds after it is power up.
This is part of the sequence during encoder initialization before actual communication is established.
I'm not sure about this specific encoder. Can you check your encoder specification?
Is this a working encoder? Can you double check the Clock, Data connections as well?
Also, if you skip this check in software - is the encoder responding as expected later on? 

If i skip this check for GPIO24

i hang there in the while(endat22Data....)

//Encoder Receive Reset - Command ERR
	retval1 = PM_endat22_setupCommand (ENCODER_RECEIVE_RESET, 0xAA, 0x2222, 0); //data1=any; data2=any
	PM_endat22_startOperation();
	while (endat22Data.dataReady != 1) {}
	retval1 = PM_endat22_receiveData(ENCODER_RECEIVE_RESET, 0);
	DELAY_US(1000000L); 	//Delay 1s

The Encoder is Endat2.2 i have the datasheet

it is a multiturn

I will check the connection again

What kind of Encoder has been used for this example ?

Are you sure that the init sequenz fits the specification ?

	// Power up EnDat 5v supply through GPIO32
	GpioDataRegs.GPBDAT.bit.GPIO32 = 1;
	DELAY_US(10000L); 	//Delay 10us
	//EncCLK high for 100ms
	EALLOW;
	GpioCtrlRegs.GPADIR.bit.GPIO6 = 1;  //set as GPIO output
	GpioDataRegs.GPASET.bit.GPIO6 = 1; //set GPIO output to be high once GPIO6 is turned to be a GPIO
	GpioCtrlRegs.GPAMUX1.bit.GPIO6 = 0;
	DELAY_US(100000L);
	//EncCLK low for ~200ns (>125ns)
	GpioDataRegs.GPADAT.bit.GPIO6 = 0;
	//EncCLK high for 425ms (>381ms)
	GpioCtrlRegs.GPAMUX1.bit.GPIO6 = 1;
	DELAY_US(425000L);

	//Ensure that EncData is now low
	if (GpioDataRegs.GPADAT.bit.GPIO24 == 1) {
		    ESTOP0;
	}

If i measure the low pulse on CLK GPIO6 at initsequence

i get 40ns and not the expected > 125ns

	//EncCLK low for ~200ns (>125ns)
	GpioDataRegs.GPADAT.bit.GPIO6 = 0;
	//EncCLK high for 425ms (>381ms)
	GpioCtrlRegs.GPAMUX1.bit.GPIO6 = 1;

so what's wrong ?

Hi,

You can add delay to match the requirement of the encoder.
after GpioDataRegs.GPADAT.bit.GPIO6 = 0;
Please add DELAY_US(value needed);
before writing GpioCtrlRegs.GPAMUX1.bit.GPIO6 = 1

HI,

still not working !

I have measured the low pulse of GPIO6 and now i have 130ns (inmserted a few nop's), but still no reaction of the encoder on GPIO24

i think the startup is now ok and fit's the specification.

I always have 3.3V at Enc-Do GPIO24, this Pin never get low.

Maybe it's a hardware issue on my IDDKit ?

Hi,

Have you referenced IDDK user guide located at
C:\ti\controlSUITE\libs\app_libs\position_manager\v01_02_00_00\endat22\Doc
PM_endat22_IDDK_UserGuide-SPRUI34.pdf

Do you have all the jumpers in place listed in 
4.2 Jumpers and Switches

Hi,

yes i have

J6, J7, J8 populated

J10 populated

J13 populated

J18 Pin1-Pin2 populated

J12 open

J14, J15, J16,J17 open

Hi,

The jumper settings look alright to me.

Also, I would suggest you check the encoder - because this is a response (GPIO24) expected from encoder.
At that juncture, MCU is not really controlling the pin. 

Hi,

if there is no encoder plugged in H6

is it ok that the GPIO24 is always high ?

Hi,

If there is no driver (encoder unplugged) GPIO24 state doesn't matter. 
Because, as I mentioned above, encoder would be driving this pin at that juncture.

Hi, That's great news. Let us know if you need any further help later on.