MPU9250, continued

This is a note on building support for the MPU9250 9-axis chip in the AdaPilot project (the AdaRacer hardware). It continues this report.

Invensense MPU9250 via SPI

This is a note on building support for the MPU9250 9-axis chip in the AdaPilot project (the AdaRacer hardware; the prototype board I have is subtly different from the one shown).
9-axis means it can measure each of acceleration, gyro and magnetic field values in 3 axes, which is very useful if your drone needs to know about its own motion.

Audacity 2.1.2 and El Capitan

I wanted to update Audacity, but the 2.1.2 version (from the official download site) wouldn’t run: I got can’t open application Audacity.

The application is damaged and can't be opened

I downloaded a new version of eclipseArduino (Arduino development within Eclipse). After unpacking and moving to /Applications, I get the message

"eclipseArduino" is damaged and can't be opened. You should move it to the Trash.

Huh.

After a lot of poking around, I found this:

1. Open Gatekeeper settings located in System Preferences > Security & Privacy.
2. Set Allow applications downloaded from: to Anywhere and confirm by pressing Allow From Anywhere.
3. Run the application.
4. Once the application has been successfully launched, it no longer goes through Gatekeeper; so, restore Gatekeeper settings to the default option Mac App Store and identified developers after successfully launching the application.

IO Expansion

I started checking out AdaCore's support library for STM32F4 boards, particularly to use I2C to talk to the PCF8547A IO expander (for possible use on the AdaPilot project).

I seem to have fritzed one or two of the pins on my STM32F429I-DISC0 board (now replaced by an updated version, STM32F429I-DISC1; that last character was a 0!); after some hair-pulling it turns out that one of said pins is used by the only externally-accessible I2C peripheral on the board; so, until the replacement arrives, here are some interesting facts about the PCF8547A.

Recovering an STM32F4 board

This is a note on overcoming a problem connecting to my STM32F429I-DISCO board.

Programming the Arduino in Eclipse

This is a note on installing the Eclipse Arduino Plugin, specifically on Windows (32-bit), with pointers to archived materiel.