Hi Mos74ph4,
If your program is running out of time, you can:
- Switch from I2C communication to SPI communication with the ADXL345, which runs much faster
- Get a faster processor
- Slow down the ADXL345 data rate
Which MMC are you using? In our experience, writing to flash is very slow. In our datalogger board, we were not able to save more than 400 Hz data continuously to a uSD card, because committing data to memory took too much time.
Best,
Nitzan