I have never played with a MMA8451, I only compared the specs of each and read a few comments I found on a couple sites comparing the two. I did read that the MMA8451 has superior noise filtering, but it is not switchable. The LIS3DH has switchable filtering, but is not as effective as the MMA8451.
I'm not sure where you're finding that, but it's not really consistent with what's in the datasheets. I think the noise differences are a little more fundamental - if you could get the same performance out of the two devices by applying filtering, you could just apply more filtering to the LIS3DH data on the MCU side and call it even, but you can't do that because filtering comes with an inherent reduction in resolution and signal fidelity. I'm pretty convinced based on observed performance that the noise differences are either inherent in the engineering of the physical MEMS sensor and/or ADC embedded in the chips, or they're coming from a higher internal oversampling rate on the MMA8451. I suspect it's the latter, because they actually document the OS rate on the MMA8451Q. That fits with the generally higher noise levels of the newer-generation devices, since oversampling costs power, and if you look at any newer device's data sheet, they ALWAYS lead with "Ultra Low Power" in the bullet list of virtues - that seems to be what sells these devices these days. Cranking down the OS rate at the expense of higher noise is the right trade-off if the main thing you care about is reducing power.
BTW- after looking at the pinout of the MMA8451 module in detail, I determined that LIS3DH generic module is not pin to pin compatible, but I will make accommodations for both modules on my board.
Yeah, there's unfortunately no standard layout for these breakout boards. Every one has its own peculiar pin layout. Makes it hard to provide a generic plug-in slot for different chips on a main board. Adafruit has adopted a fairly uniform pin layout that they use with nearly all of their STEMMA boards, so a main board with a slot for the Adafruit LIS3DH module will likely be compatible with future Adafruit accelerometer breakouts. But that doesn't work with their own MMA8451Q board, because that pre-dates the uniform STEMMA layout and has its own unique footprint. For the DIY board, I just added two headers side-by-side, one for the STEMMA layout and one for the Adafruit MMA8451Q layout.
Edited by mjr, 23 September 2025 - 05:49 PM.
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