TODO

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Revision as of 02:51, 27 March 2010 by Uwe Hermann (talk | contribs) (I'll create a generic, open-source FX2 logic analyzer firmware. Some parts already work, will post infos soon.)
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This is a random list of TODO items for the code and/or ideas for improvements.

General

  • Remove dependency on glib and gmodule (various reasons), at least in libsigrok, probably also in sigrok-cli.
    • A new linked list implementation must be found, or written, that duplicates the important parts of glib's GSList (singly-linked list).

libsigrok

  • Test whether the libusb 1.0 Windows port works (seems to build fine using MinGW).
  • Merge all header files in a single sigrok.h (possibly another sigrok-internal.h which is not visible to the lib users).
  • Session loading from file.
  • sigrok_errno:
    • Most backend functions return status as an integer, which is SIGROK_OK if all went well, or SIGROK_NOK and similar if an error occurred.
    • However there is no way to pass any information back as to what went wrong — and this is important for user-friendliness.
    • Perhaps an error code is not enough; maybe something like sigrok_errno(errorcode, "unsupported device") is better.
    • Both the cmdline and GUI interfaces need this, really, so it should be a backend library thing.

libsigrokdecode

  • Keep this independent of libsigrok and any logic analyzer hardware. It should work purely on streams / buffers of bytes to be usable by other projects.

Hardware drivers

  • Bus/driver-independent device instance struct, to replace usb_device_instance and serial_device_instance. Once this is done, device instance-specific information can be cleanly separated and tacked on to the generic device instance:
    • Clean up device-specific globals in hardware drivers, to properly permit multiple devices per driver.
    • Vendor/model/version scheme in hardware drivers.

Demo driver

It would be good if sigrok would ship with a built-in driver that always works, regardless of hardware connected. This driver would be configurable to provide a clock on a virtual pin, with configurable frequency. It could support multiple of these, at different frequencies.

In addition to giving anyone something to do with sigrok to try it out, this may also have some use cases outside of this: perhaps as a reference clock, next to a live capture.

Since this driver only needs to change to 0/1 at a configurable interval, and the interval is exactly the same as the count of the samples in the datafeed it outputs, the signal it generates would thus be 100% perfect, making it an interesting reference.

Open-source firmware for the FX2 devices

The Cypress FX2-based devices, such as the Saleae Logic and the USBee SX, use only a minimal vendor-provided firmware. The only thing it really does is set the sample rate and turn on the chip's auto-mode. Nevertheless, the vendors provide the firmware as a binary blob, with no source.

It would be great if sigrok could ship with an own firmware implementation for these devices. Some links:

  • SDCC, the Small Devices C Compiler, is a compiler specifically suited to small MCUs, and has support for the 8051 core in the FX2.
  • fx2lib is an open-source library for writing firmware on the FX2. It has a number of interesting functions, including implementing custom USB vendor commands.
  • GNU Radio's USRP2 board has an FX2 on it, and GNU Radio has extensive custom firmware for it.

Uwe Hermann is working on an open-source FX2 firmware for use with various logic analyzers.

sigrok-cli

sigrok-gui

Decoders

Code quality and build

  • Consistently use 'samplerate' instead of 'rate'.
  • Consistently use uint64_t for large data types such as samplerate, number of samples, etc.