我们课题组设计一个电路，用来获取微生物燃料电池（MFC）的能量，我们打算用贵公司的BQ25570，并参照《bq25570 nano power boost charger and buck converter for energy harvester powered applications datasheet (Rev. G)》中Figure 24. Typical Externally Set MPPT Application Circuit，设计了电路。由于MFC受微生物活性和底物浓度的影响，内阻是在动态变化的，因此最大功率点也是变化的。所以，我们希望通过上位机计算并控制最大功率点，但是现在我们不知道BQ25570是如何通过外部电路实时改变MPPT的。我们不是需要固定80%MPPT或50%MPPT。该如何通过MCU来动态调整MPPT呢？可以通过MCU控制某一个针脚的电压来调整MPPT吗？如果可以的话，设计时电压和MPPT的百分比的对应关系是什么？
Our research group is designing a circuit to harness energy from Microbial Fuel Cells (MFCs), and we plan to use your company’s BQ25570. We are referring to the “bq25570 nano power boost charger and buck converter for energy harvester powered applications datasheet (Rev. G)” and specifically Figure 24, which illustrates the typical externally set MPPT application circuit for our design. Due to the dynamic nature of the internal resistance of the MFC, influenced by microbial activity and substrate concentration, the maximum power point is also variable. Therefore, we hope to calculate and control the maximum power point through a host computer in real-time. However, we are currently unsure how the BQ25570 can adjust the MPPT through external circuits. We do not need a fixed 80% MPPT or 50% MPPT. We require a dynamic control system that adjusts to the changing conditions of the MFC. Could you please provide guidance on how to achieve this? How can one dynamically adjust MPPT through an MCU? Can MPPT be adjusted by controlling the voltage at a certain pin with an MCU? If so, what is the corresponding relationship between voltage and MPPT percentage in the design?