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ICM-42670-P seems like a widely available low-power option (and apparently low noise) . Need to find out the desired orientation and placement of the IMU on the board (Since it’s recommended for it to be in the center of the drone and to align expectedly with the yaw/pitch/roll axis)

EFS seems to planning to implement a standard IMU that they use for all projects so they don’t have to remake drivers as often. They have not committed to but the ICM-42688 sounds like it is likely to be the one. It is slightly more expensive than the one above but still super cheap and seems to me much more common, meaning more community support. The features are very similar between both.

During this weekly EE meeting, it was mentioned that EFS would be interested in having a magnetometer/compass as well. They also do not care as much about keeping the IMU in this project the same as the ones they are looking at. The ICM-20948 seems to be the most affordable readily available IMU that contains a magnetometer and it seems to be popular. Also, EFS may be working with the ICM-20948 instead of the ICM-42688 for their standard IMU so this should be a good choice.

While the placement of the IMU is not critical, it should be placed as close to the center as is convenient. This way rotation will have less of an impact on output acceleration and EFS would have to worry less about factoring the offset into calculations.

The IMU should be placed according to the following image to align the axes of the IMU with the axes of the board. It should be discussed which axis is defined as forward and which side of the board is considered forward.

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Having the IMU in the board is not a priority since the hardware has not been confirmed and no one in EFS has relevant experience yet to write the firmware.

EFS has changed their mind and this would be useful for future development.

The IMU can communicate with I2C , I3C, and SPI. I2C and SPI already have ports on the interface board so we could potentially route these to the IMU and use jumper pins so the IMU can be disconnected when this port needs to be used. Unused pins on the STM32 are not connected to the connectors in the ZP3 schematic so these can not be used to to connect to the IMU on the interface board.

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Now there seems to be considerations for a barometer and compass/magnetometer on board. EFS has been asked what they would like to have on it. Edits have been made above to include the magnetometer. The barometer seems excessive and would require a less common IMU or separate component. This likely would not be included.

This document from September outlines some potential improvements for the ZP3 board. It has not been touched since. EFS has been asked if this is still relevant and if they want these suggestions to be added.

This seems beyond the scope of the project but I will remind EFS again just in case.