Is the 16 g scale still the only scale that the accelerometer on the sensor expansion board can be set at?

[paulwb]

I asked back in August last year, and I wanted to rebuild a project using only Pixelblaze parts. But I think I need the resolution 8 g gives, and I may even want to go down to the 4 g range.

Last time I asked, it looked like a new board rev is needed for this to happen, not a software change.

Accelerometer values to m/s^2

The accelerometer is specified as Range: +/- 16 g Resolution: 12 mg per digit, sign and 12 bits with 1 g being about 0.020. I was curious about converting this value into m/s^2, so I messed around until I found a factor that seems to work, and that factor is 512, i.e. accelerometer[2] * 512 = ~ 9.8. Does this sound right? It’s also quite noisy, given the 16 g scale. Do you plan on providing any way to set the accelerometer gain to 2g and 4g? I haven’t tested, but I’m not sure my applicati…

Is this still the case, and are there plans for a board rev that enables this setting?

Thanks,

Paul

[wizard]

Hi @paulwb ,
Right, it’s coded in the sensor board firmware. It is possible to reflash the firmware for the sensor board to change it (with an STM32 programmer), but isn’t possible from Pixelblaze itself.

Depending on what you need, a filter might help considerably with any jitter, at the cost of responsiveness.

[paulwb]

@wizard

Right, it’s coded in the sensor board firmware. It is possible to reflash the firmware for the sensor board to change it (with an STM32 programmer), but isn’t possible from Pixelblaze itself.

Hmm. I do have an ST Nucleo board that I never did anything with and might be able to work as a programmer, but getting a whole ST toolchain up and running just to change a single value might be more than I want to do for this project.

I should experiment with a filter and see how that goes. Responsiveness is key for the two programs I’d use it for. Hmm.

An external board like Adafruit’s ADXL345 is ruled out, because I’d need to use an I2C/SPI library to get the data from it, which is not a possibility here. Maybe I can look for accelerometer boards that have analog out.