Could not receive the true unswer from VL53L1

[niltec]

Gentlemen! Sorry for bothering you.

I try to use VL53L1 with the Light Driver.

The power level is 3.0 V, so I changed the Initialization data array, cell 0x2E from 0x00 to 0x01 and cell 0x2F from 0x00 to 0x01.

I wait for the Device ready (SensorState = 0x03), than initialize of the Device (I checked of the ASK by Oscilloscope - it was good).

I could not receive 0xEEAC by readind a word from 0x010F and 0x0110 cells. Insted of this I stable receive 0xEACC.

I started of the measurement in loop and checked of the CheckForDataReady () function. The DataByte was constantly 0x0.

May be somebody could give me an advice where is my error?

[niltec]

Sorry, I have forgotten of the important moment. Could anybody give me a full list of registers with the meaning of the bits values (or Internet address of the corresponding document). I could not find of the important data.

[John E KVAM]

Unfortunately ST does not publish the register map for this device. It's a pretty complex device and there are way too many settings that would just get users in trouble. It's way better to use the API we publish.

As for voltage I suggest:

1)	Modify the code in VL53L1X_def.h
 
const uint8_t VL51L1X_DEFAULT_CONFIGURATION[] = {
0x00, /* Reg 0x2d is set bit 2 and 5 at 1 for mode fast plus (1MHz I2C), else don't touch*/
#ifdef USE_I2C_2V8
0x01, /* Reg 0x2e is don't touch bit 0 if I2C pulled up at 1.8V, else set bit 0 to 1 for 2.8V*/
#else
0x00, /* Reg 0x2e is don't touch bit 0 if I2C pulled up at 1.8V, else set bit 0 to 1 for 2.8V*/
#endif

You can do the same thing for the Interrupt line (0x2F).

The EACC you got is correct. There is a terrible typo in the data sheet.

My code, that works just fine is:

 while(sensorState==0){
		status += VL53L1X_BootState(dev, &sensorState);
	HAL_Delay(2);
 }
 printf("Chip booted\n");
 
 /* This function must to be called to initialize the sensor with the default setting */
 status += VL53L1X_SensorInit(dev);
 
 /* Optional functions to be used to change the main ranging parameters according the application requirements to get the best ranging performances */
 status += VL53L1X_SetDistanceMode(dev, 2); /* 1=short, 2=long */
 status += VL53L1X_SetTimingBudgetInMs(dev, 100); /* in ms possible values [20, 50, 100, 200, 500] */
 status += VL53L1X_SetInterMeasurementInMs(dev, 100); /* in ms, IM must be > = TB */
// status += VL53L1X_SetOffset(dev,20); /* offset compensation in mm */
// status += VL53L1X_SetROI(dev, 16, 16); /* minimum ROI 4,4 */
//	status += VL53L1X_CalibrateOffset(dev, 140, &offset); /* may take few second to perform the offset cal*/
//	status += VL53L1X_CalibrateXtalk(dev, 1000, &xtalk); /* may take few second to perform the xtalk cal */
 printf("VL53L1X Ultra Lite Driver Example running ...\n");
 status += VL53L1X_StartRanging(dev); /* This function has to be called to enable the ranging */
 while(1){ /* read and display data */
	 while (dataReady == 0){
		 status += VL53L1X_CheckForDataReady(dev, &dataReady);
		 HAL_Delay(2);
	 }
	 dataReady = 0;
	 status += VL53L1X_GetRangeStatus(dev, &RangeStatus);
	 status += VL53L1X_GetDistance(dev, &Distance);
	 status += VL53L1X_GetSignalRate(dev, &SignalRate);
	 status += VL53L1X_GetAmbientRate(dev, &AmbientRate);
	 status += VL53L1X_GetSpadNb(dev, &SpadNum);
	 status += VL53L1X_ClearInterrupt(dev); /* clear interrupt has to be called to enable next interrupt*/
	 printf("%u, %u, %u, %u, %u\n", RangeStatus, Distance, SignalRate, AmbientRate, SpadNum);
 }
}

Notice how I used "status +="? As all status returns should be zero, somewhere in your loop put a single check for a non-zero return.

I expect you have one somewhere.

The only other failure I have ever heard of is a glitch on the reset line - that sometimes reboots the chip. (That line is why too sensitive.)

So if your I2C line is still doing I/O, it could be that your chip rebooted. Stronger pull-up is suggested.

[niltec]

Good day, John!

Really thanks for the answer.

[_r_y_a_n]

@John E KVAM​ 

"The EACC you got is correct. There is a terrible typo in the data sheet."

I just hit this same problem. Thanks for the updated information in this thread - I thought I was going mad. :grinning_face:

Any chance they can update that data sheet to avoid confusing future readers?