Gravity Matrix 8x8 Image Memory
JohnPiccirillo 2026-07-29 07:36:49 37 Views2 Replies I'm having trouble testing the Gravity matrix 8x8.
1. Testing a blank field, with limits on the max range, I get, as expected a blank array of pixels.
2. Putting a 2x4" about 50 cm in front of the sensor, the appropriate pixels show the 2x4 distance,
with some scattering of values outside the 2x4 image.
3. Removing the 2x4, the pixels show the previous values.
I tried waiting 250 ms between image updates but that didn't make any difference.
What am I doing wrong?
Thanks,
John-
Thanks. I'll check it out tomorrow or the next day.
When I initially tried to update to V1.3, a month or so ago, I got an error message.
John-
JohnPiccirillo I think I know what's going on here. The SEN0628 sensor had a firmware bug in earlier versions where invalid/out-of-range readings would just keep showing the previous value instead of clearing. That's exactly what you're seeing — the 2x4 object is gone but the pixels still show the old distances.
The fix is straightforward: update the firmware to V1.3. DFRobot patched this in the latest version — invalid pixels now return 4000 instead of hanging onto stale data. You can grab the UF2 file from the SEN0628 wiki page.
To flash it, just connect the sensor via USB-C, hold the BOOT button while plugging it in, and it'll show up as a USB drive. Drop the UF2 file onto it and you're done.
A couple other things:
The scattering you're seeing outside the 2x4 area is pretty normal for this sensor at ~50cm — the VL53L7CX has some cross-talk between zones, especially with smaller targets. Not much you can do about that short of moving closer or using a larger target.
And 250ms wait won't help much because the sensor refreshes at up to 60Hz, so it should already be updating faster than that. The issue really is the firmware bug keeping old values around.
Let me know if the update fixes it!
Jason.Miao 