Sunday, 14 August 2016

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.

Sunday, 10 July 2016

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.

Sunday, 17 April 2016

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.

Wednesday, 17 February 2016

Saturday, 30 January 2016

Arduino Due and the Watchdog

A watchdog is used to detect when a system has gone off with the fairies; you have to reset the watchdog timer ("pat the watchdog") every so often or it takes some recovery action. In the case of the Arduino Due, with the ATSAM3X8E MCU, the recovery action is to reset the CPU.

In the ATSAM3X8E (and probably other Atmel MCUs, too), the watchdog timeout defaults to 16 seconds, and the default hardware state is that the watchdog is enabled! (the default in the Atmel Software Framework is to disable the watchdog unless you have defined CONF_BOARD_KEEP_WATCHDOG_AT_INIT).

Tuesday, 18 August 2015

Arduino Due/Segger J-Link EDU

I’ve been porting my Cortex-based RTS to Arduino Due, using the J-Link JTAG interface (because who can make an RTS without a debugger?). I’ve probably forgotten my initial problems with ST-LINK (an equivalent interface included for free on the STM32F4 board, supported by OSS software), but it seemed a much less trying experience than with Segger.

There are two things with J-Link GDB Server: first, it seems like a bad idea to keep the server alive after a GDB session ends, so start it with -singlerun; and second, you absolutely must issue monitor reset before running your program. If you don’t you’ll end up like I did, scratching my head for three days trying to understand why I was getting a HardFault at the SVC that FreeRTOS uses to kick tasking off.