Arduino ADC supplement

Hi all, Kinda new to the whole blog thing, but I have been wondering about the IMU5DOF and Arduino's lack of substantial ADC bits for resolution for a heli. Anyway, Could we supplement the ADC up to 2048 bits by combining two ADC channels like this?You know I have been thinking about the resolution issue with 300d/s gyros and the resolution of the AVR168 chips. It seems to me if we think outside the box for a moment the problem can be easily solved. It would require 3 op amps per channel but it may be worth it.The first op amd is a unity gain buffer. The other two op amps are configured to have 0 -3.3v for an input of 0-1.5v the second op amp would drive an ADC1 input directly. The third op amdwould be biased so that it did not produce output until it reveived an input of 1.5v. This coulkd be easily achieved with two diodes in series to the input of op amp 3 the voltage drop across each would be .7v and two would be 1.4v. A forward bias would be achieved at ~1.4v hence setting the bias. The third op amp would feed ADC2 and readings would only be taken from this if ADC1 achieved an overflow condition (full 1024 bits). This should give more resolution than ever needed. :)

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  • I don't have a lot of embedded or electronics background but I did some research on op-amps and I don't think that this will work. I don't think that increasing the resolution of the ADC could increase the accuracy and sensitivity of the IMU (or 300d/s gyro specifically). It's similar to increasing the resolution of a compressed picture. It will be increased but the data would be an approximation.

  • average two readings - its bound to be easier than this.
  • T3
    Looks good on paper, but in practice this would be a mess on PCB board.
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