AspirinIMU
Aspirin IMU
The next generation flat multi degree of freedom inertial measurement unit. It uses digital 3-axis sensors which allow for a very small size and price. Other features include onboard voltage regulators, EEPROM for storing calibration data and extra sensors such as a barometer.
Hardware Revision History
| Version # | Release Date | Release Notes |
|---|---|---|
| v2.1r1(current) | 08/2012 | 2nd Gen Minor Revision |
| v2.1 | 03/2012 | 2nd Gen Production Release |
| v2.0 | 11/2011 | 2nd Gen Prototype |
| v1.5 | 04/2011 | Updated Production Release |
| v1.4 | 03/2011 | Prototype Update |
| v1.3 | 08/2010 | Initial Production Release |
| v1.2 | 07/2010 | Prototype Update |
| v1.1 | 07/2010 | Prototype Update |
| v1.0 | 07/2010 | Initial Prototype |
Features
- 3-axis accelerometer
- 3-axis gyroscope
- 3-axis magnetometer
- Onboard voltage regulation
- Onboard I2C EEPROM
- Onboard barometer (v2.1)
- Standard footprint across versions
- Single PCB flat form-factor
- Fits directly onto Lisa/M, carriers for Booz and Lisa/L, or for LPC21xx integration
| Version | Accelerometer | Gyroscope | Magnetometer | Barometer | Regulators | EEPROM | Comments |
|---|---|---|---|---|---|---|---|
| v2.1 | MPU-6000 | MPU-6000 | HMC5883 | MS5611 | 1x 3.3V (LP2992) | yes | |
| v2.0 | MPU-6000 | MPU-6000 | HMC5883 | none | 1x 3.3V (LP2992) | yes | |
| v1.5 | ADXL345 | IMU-3000 | HMC5883 | none | 2x 3.3V (LP2992) | yes | |
| v1.4 | ADXL345 | IMU-3000 | HMC5883 | none | 2x 3.3V (LP2992) | yes | |
| v1.3 | ADXL345 | ITG-3200 | HMC5843 | none | 2x 3.3V (LP2992) | yes | |
| v1.2 | ADXL345 | ITG-3200 | HMC5843 | none | 2x 3.3V (LP2992) | yes | |
| v1.1 | ADXL345 | ITG-3200 | HMC5843 | none | 2x 3.3V (LP2992) | yes | |
| v1.0 | ADXL345 | ITG-3200 | HMC5843 | none | 2x 3.3V (LP2992) | yes | Also has SC18IS600 SPI-I2C interface |
Note: Aspirin 2.1 comes in several population versions. The current version available at http://thequadshot.com has the MPU-6000, HMC5843, and MS5611-01BA03 mounted. You can find the list of fitted sensors on Aspirin 2.1 in the eeprom block 4.
Aspirin V1.4 IMU front
Aspirin V1.4 IMU back
Aspirin V1.4 IMU on Lisa/L compatible carrier board
Aspirin flat carrier board for Lisa/L (without IMU mounted)
Aspirin IMU 2.1 bottom side
Aspirin IMU 2.1 top side
Aspirin IMU 2.1 top side no barometer mounted
Aspirin IMU 2.1 top side no barometer and no magnetometer mounted
Pinout
Note that Aspirin uses a standard footprint and pinout across all versions, with certain exceptions. The chip select (CS) and interrupt (Int) pins are not always assigned to the same devices. A good example is with the introduction of the MPU-6000 device. Check the schematics for details.
Warning: When mounting Aspirin on Lisa/M note that the pin labeled GND on Aspirin (in the right upper corner on the following picture) is connected on Lisa/M to GYRO_SS. To prevent a software error induced shorting of the Lisa/M GYRO_SS pin to ground, remove the castellation or remove the connection on that pad.
In the v2.1r1 versions of Aspirin ("r1" silkscreened onto PCB) the right upper GND pad was changed to Non Connected (NC), resolving the issue.
Block Diagrams
Aspirin 1.x to STM32 protocol connections
Aspirin 2.x to STM32 default protocol connections (MPU-6000 slave I2C)
Aspirin 2.x to STM32 alternative protocol connections (STM32 direct I2C)
Schematics
Schematics are available under 
license. For additional intermediate schematics see Downloads.
Aspirin IMU V1.3 schematic
Aspirin IMU V1.5 schematic
Aspirin IMU V2.1 schematic
Drivers and Support
Please see the IMU subsystem page for details on configuring Paparazzi for using an Aspirin IMU.
The drivers for this IMU are available in the Paparazzi GitHub repository.
PCB and assembled boards suppliers
Aspirin IMU is available in the Transition Robotics/Quadshot Online Shop.
There are three options of Aspirin IMU:
Mechanical Dimensions
The overall height of the board is about 3mm.
Downloads
Source files
- download available on GitHub: Aspirin IMU and Carrier Board Cadsoft Eagle 6 Design
Gerber & Drill files
- download NOT YET AVAILABLE Need generated gerbers and drill files
Assembly files
- download NOT YET AVAILABLE Need Aspirin Components layouts (pdf)
- download NOT YET AVAILABLE Need Aspirin Bill Of Material