Chip versus board markings on LSM303?

I am confused by the chip markings on two different examples of the Pololu compass/accelerometer carrier (LSM303DLH #1250 and LSM303DLM #1273), purchased a few months apart.

One chip (product #1250) has 4 lines: 4XGK / HM55 / 043 / MLT while the other (product #1273) has SLJB / 303DH / 143 / MLT The boards appear to be otherwise identical with respect to markings. I was finally able to sort out which was which by checking my order history, and discovered that the chips are slightly different, most importantly with regard to axis orientation. However, if I had taken both carriers out of their shipping bags I would now be at a loss as to which is which, as the chip markings make no sense to me.

Given that Pololu products like these are being discontinued/replaced and/or changing product numbers so quickly, it would be helpful if a Pololu product number could be put on each board, so customers could keep track of their inventory.

Thanks, Jim Remington

Hi, Jim.

I’m glad you were able to figure out which board is which. The two boards have the same axis orientation, though some of the register locations changed between the DLH and the DLM. The DLM is a drop-in replacement for the DLH, so the same PCB is used. If we know ahead of time that we will be using the same PCB for multiple products, we design them to be uniquely marked, but it is difficult to predict what new MEMS sensors will be coming out down the road.

- Ben