Issue with VL53L1 on AVR64DB32: VL53L1_WaitMeasurementDataReady frequently times out

[etogashi]

Hello,

I am working on a project using an AVR64DB32 MCU and the VL53L1 time-of-flight sensor over I2C.
I downloaded the official API from ST (STSW-IMG007) and adapted vl53l1_platform.c to my environment.
Since my I2C communication library is written in C++, I converted it into vl53l1_platform.cpp.

I also wrote a simple distance measurement test program (main.cpp).
My custom I2C driver (I2cDriver.cpp) is already used in other projects and seems reliable, so I assume the issue is not primarily there. I have attached these files for reference.

The issue:

Inside the while loop, I repeatedly call VL53L1_WaitMeasurementDataReady.

• If successful, I call VL53L1_GetRangingMeasurementData and then VL53L1_ClearInterruptAndStartMeasurement. In this case, I blink an LED once.

• If it fails with VL53L1_ERROR_TIME_OUT, I blink the LED twice. For any other error, I blink three times.

• After each loop iteration, whether success or failure, I wait one second before retrying.

When running the program, I observe the following behavior:

• Several consecutive failures (timeout) occur.

• Then, one successful measurement occurs.

• This pattern repeats.

When I break in debug mode, I can see that the RangingData values are valid on success.
So, the sensor does measure correctly sometimes.
However, it seems to require many seconds before a measurement succeeds.

According to the documentation, the VL53L1 should be able to deliver measurements at least once per second, but my behavior is much slower.

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What I tried:

I experimented with:

• VL53L1_SetDistanceMode

• VL53L1_SetMeasurementTimingBudgetMicroSeconds

• VL53L1_SetInterMeasurementPeriodMilliSeconds

But none of these improved the situation.

Note: For simplicity, the attached code does not check every initialization return value, but in my real program I do, and all calls return VL53L1_ERROR_NONE.

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Additional information:

• I2C bus speed is 400 kHz.

• Power supply: normally from AA batteries, but I also tested with a regulated bench power supply, so I believe insufficient current is not the cause.

• Hardware schematic is attached (see image).

  • GPIO1 is left floating (not used).

  • XSHUT is not controlled by the MCU; instead, it is pulled up with a 10 kΩ resistor.

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My questions:

1. Why does VL53L1_WaitMeasurementDataReady fail with repeated timeouts before eventually succeeding?

2. Is there something fundamental I am missing in the initialization or measurement loop?

3. Could the way I adapted the vl53l1_platform.c file to my custom C++ I2C driver be the cause?

[etogashi]

These are the remaining files.

[etogashi · Accepted solution]

Hello everyone, just a quick follow-up.

I managed to solve the problem by switching to another ST library: the VL53L1X Ultra Lite Driver (STSW-IMG009). With this library, the sensor operates as expected.

While the exact cause of the timeouts with the previous library is still unknown, I wanted to share my working code here for anyone who might face a similar issue in the future. I have attached the new files.

[John_Kvam]

Congrats on finding a solution. The UltraLite Driver has always been a favorite of mine as well. 

One note. As you did not set a timing budget or an inter-measurement period, your sensor is taking 30 measurements per second and using a lot of power. If you are going to wait 1000ms between outputs you can range a lot less often. 

It would save quite a bit of power. 

But then again maybe this is just the start of your project, and you plan on doing something more than just blinking a light. In which case, I think you've gotten started. 

Good luck.

- john

[etogashi]

Hi John,

Thanks for the great advice! You're right, this is just the beginning of my project, and power saving is my next step.

I may come back with more questions on that topic. Thanks again for your help!