Time to get some experience with 32bit microcontrollers

After almost 50 years working with 8bit microcomputers and microcontrollers, I thought it about time to get my hands dirty on some 32bit microcontrollers.

The plan is to investigate two streams, one ST Microcontoller based and one ATMEL based, both ARM architecture. Continue reading Time to get some experience with 32bit microcontrollers

Capturing the AVR hex file built by Arduino on Windows

One often sees enquiries by people trying to save the hex file made during the Arduino build process.

It is not trivial, as in their wisdom, Arduino hides these details, and builds the hex file in a randomly named temporary directory for each IDE which it deletes when the IDE is closed.

There are times when you may want to save the hex file, perhaps to load it without a bootloader or using a non-supported bootloader, Flashing LED driver using an ESC was just such a project. Continue reading Capturing the AVR hex file built by Arduino on Windows

Cron configuration improvements for Raspberry Pi

One of the shortcomings or RPi for (m)any serious applications is that it lacks a hardware clock so when it starts, the clock is not set correctly.

This deficiency can be overcome to some extent for some applications with the fake-hwclock module and SNTP where the RPi is always connected to a network.

The standard scheduling daemon cron does not run tasks that were missed because the system was not running at the time they were scheduled. It is a significant shortcoming that has been overcome by adding another element, anacron, which wraps the cron tasks and is scheduled by cron and at startup. All of this is very dependent on correct clock time, and for RPi systems that lack a hardware clock (the out of the box hardware), the system time can be quite wrong at the time anacron is scheduled as part of the startup procedure.
Continue reading Cron configuration improvements for Raspberry Pi

Real time clock for Raspberry Pi

One of the shortcomings or RPi for (m)any serious applications is that it lacks a hardware clock so when it starts, the clock is not set correctly.

This deficiency can be overcome to some extent for some applications with the fake-hwclock module and SNTP, but this is not a solution if the RPi is not always connected to a network time reference.

One solution is a real time clock module such as the DS1307, or better still the DS3231. The latter has an internal crystal with 2ppm (5s/month) accuracy from 0-40° which is much better than typically achieved with a DS1307 (which is dependent on the external crystal). Continue reading Real time clock for Raspberry Pi