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melexis / mlx90640-library

MLX90640 library functions
Apache License 2.0
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EEPROM validity bit discrepancy in MLX90640ESF-BAB devices #37

Closed sdbakker closed 5 years ago

sdbakker commented 5 years ago

I have 3 BAA 120 degree and 3 BAB 60 degree devices. Using this library I have no problems using the BAA devices. However the BAB devices failed to extract the EEPROM parameters.

After closer investigation it seems that the function https://github.com/melexis/mlx90640-library/blob/0b76a54c480f565e7131fadaab7bb82a76f420c4/functions/MLX90640_API.cpp#L1277 checks bit 6 of addres 0x240A for 0. For all 3 BAB devices this bit is 1:

BAA 0x240A: 0x48D - 10010001101
BAB 0x240A: 0x4D9 - 10011011001

If I alter the EEPROM validity check to reflect this all else works like expected.

I can not find any reference of this discrepancy between BAA and BAB devices in the datasheet, this library or errata. Is this a recent change, a fluke or some undocumented difference?

slavysis commented 5 years ago

As there were some changes in the EEPROM encoding, the CheckEEPROMValid function will be removed from the driver (hopefully very soon). For more details, please refer to that post: https://github.com/melexis/mlx90640-library/issues/32#issuecomment-480719293

sdbakker commented 5 years ago

@slavysis thanks for your reaction and apologies for the duplication! I somehow missed that issue.