SparkFun ICM-20948 Arduino Library Helper

This skill is primarily an index / entry point into the files in this folder. Use it to quickly choose the right example sketch and reference document when working with the SparkFun ICM-20948 Arduino library (ICM_20948.h) and the SparkFun 9DoF IMU Breakout (ICM-20948).

What’s in this folder (you should consult these)

• examples/: Arduino .ino sketches (best starting point)
• DMP.md: DMP notes (quaternions, Euler, raw accel, multi-sensor, caveats)
• icm20948_datasheet.md: datasheet notes / deep reference material

Example sketches (choose the closest one first)

Start with the simplest example that matches your hardware + goal, then modify incrementally.

• examples/Example1_Basics.ino

  • Use for: first bring-up, basic I2C/SPI wiring, streaming AGMT data.
  • Key patterns: ICM_20948_I2C / ICM_20948_SPI, begin(...), statusString(), dataReady() → getAGMT().

• examples/Example2_Advanced.ino

  • Use for: beyond basics; more configuration and “how the library is structured”.

• examples/Example3_Interrupts.ino

  • Use for: “data ready” interrupts.
  • Hardware note: requires wiring breakout INT → MCU pin (INT_PIN).

• examples/Example4_WakeOnMotion.ino

  • Use for: low-power / motion-trigger workflows.

• examples/Example5_DualSPITest.ino

  • Use for: SPI-focused setup and/or validating SPI behavior (and conflicts).

DMP examples (read DMP.md too)

Many DMP sketches require enabling DMP support in the SparkFun library: you may need to edit the library source and enable ICM_20948_USE_DMP (see the comments at the top of the DMP examples).

• examples/Example6_DMP_Quat9_Orientation.ino

  • Use for: DMP quaternion orientation (Quat9).
  • Notes: includes important DMP enablement instructions in comments.

• examples/Example7_DMP_Quat6_EulerAngles.ino

  • Use for: DMP quaternion (Quat6) and converting to Euler angles.

• examples/Example8_DMP_RawAccel.ino

  • Use for: DMP raw accelerometer output.

• examples/Example9_DMP_MultipleSensors.ino

  • Use for: DMP with multiple sensor outputs enabled at once.

• examples/Example10_DMP_FastMultipleSensors.ino

  • Use for: higher-rate DMP output / performance-focused configuration.

• examples/Example11_DMP_Bias_Save_Restore_ESP32.ino

  • Use for: ESP32-specific flow to save/restore DMP bias.

When to use this skill

Use this skill when the user:

• Mentions ICM-20948, SparkFun 9DoF IMU Breakout, or ICM_20948.h
• Is writing an Arduino sketch that uses ICM_20948_I2C or ICM_20948_SPI
• Has initialization issues and sees non-OK myICM.status
• Wants “raw vs scaled” explanations and correct units / scaling
• Needs help porting SparkFun examples to a different MCU or interface
• Is working with the DMP and needs help interpreting outputs

How the agent should use this folder

When answering, prefer to:

• Point to the most relevant example and explain the minimal edits needed (pins, interface, address, serial port).
• Cite DMP.md for DMP configuration and interpretation questions.
• Cite icm20948_datasheet.md only when register-level detail or edge-case behavior is needed.

Troubleshooting checklist (fast path)

If bring-up fails, ask for/verify:

• Interface: I2C vs SPI
• Board + pin mapping (SDA/SCL or SCK/MISO/MOSI/CS)
• ADR/AD0 jumper setting (I2C address bit)
• Serial output of myICM.statusString()
• Whether dataReady() ever becomes true

Minimal code pointers (where to look)

Instead of pasting long code blocks, refer users to:

• Example1_Basics.ino for begin(...), statusString(), and dataReady() → getAGMT()
• Example3_Interrupts.ino for wiring and attachInterrupt(...) with the breakout INT pin
• Example6..11 for DMP enablement notes and output formats

Example prompts that should trigger this skill

• “Write an ESP32 sketch to read accel/gyro/mag from SparkFun ICM-20948 over I2C.”
• “My myICM.begin(Wire, 1) returns an error—help me debug wiring and address.”
• “Port SparkFun Example1_Basics to SPI with CS on pin 5.”
• “How do I use the DMP quaternion output and convert it to Euler angles?”
• “My magnetometer readings look wrong—what should I verify?”