freemcan

What is freemcan?

freemcan is software for using custom gamma spectrum analyzer and geiger counter hardware. It consists of both the firmware to run on the custom hardware and of hostware to run a Linux PC.

As the custom hardware contains a high voltage generator, we have not published the schematics or board files for its hardware yet.

Why the name?

• We wanted it to be Free Software.

• MCA is the acronym for Multi Channel Analyzer which is the common term for the device.

• "freemca" produced a few hits on Google. "freemcan" did not. Brand name collision wise, an unused word appeared to be the better choice.

The Plan

(FIXME) No plan.

Building

For a reasonably quick build, we recommend a parallel build:

$ make -j -O -l 5

Otherwise, you can build serially with

$ make

Installation is not supported at this time.

Software Requirements

• GNU make

• avr-gcc based AVR toolchain

• avr-binutils >= 2.19 (we use INSERT AFTER in linker scripts)

• POSIX/GNU/Linux/Unix host system

• gcc compiler for host system

For building the internal code documentation (mostly of interest to freemcan developers), you additionally need

• doxygen

• graphviz

• sloccount

  Optionally, for creating the source lines of code (SLOC) summary.

Usage

TBA.

The License

LGPLv2.1+

Hacking

Subdirectory Contents

• firmware/

  The device firmware for Atmel ATmega644 microcontroller

• code-comparison/

  Some common tasks our firmware needs written in portable C and compiled for all platforms we have a cross compiler for. This lets us compare the assembly language generated for those platforms.

• hostware/

  All the software running on the PC host. For lack of a better word, we called it "hostware" to distinguish it from the "firmware".

• emulator/

  Simple attempt at emulating the device connected to a device file by having an Erlang program connected to a Unix domain socket.

Ideas

• cbi/sbi do not modify SREG. That makes it easy to write an ISR without saving any registers, like e.g.:

  foo_vector:           /* enter ISR: 5 clock cycles */
          sbi foo,bar              /* 2 clock cycles */
          reti          /* leave ISR: 5 clock cycles */
  

  for doing the reset timing stuff, potentially at ADC trigger, and after timer IRQ counted delay later, or similar stuff.

Known issues

• ccache is known to not generate the *.i and *.s when called with the -save-temps=obj option. Until your local ccache has been fixed, set CCACHE_DISABLE=true or remove /usr/lib/ccache or /usr/lib64/ccache from the PATH as a workaround.

  The same issue applies to other files like linker map files (-Wl,-Map=$(@:.elf=.map),--cref) and assembly listing files (-Wa,-adhlns=$(@:.o=.lst)).