##regdefs A framework providing a compact way of specifying registers, including addresses, groupings of registers into devices (and unions of sub-groupings...analogous to C structs and unions), and the various flags and bitfields they contain. The specification can then be used to do a number of things, such as generate a C include file or documentation, or interactively work with a device through a Pry or IRB console and some code to remotely set and read registers.
The main benefit is the compact and clear specification DSL. Registers are specified in a simple and clear fashion that can more easily be reviewed and checked for errors, more easily be written without introducing errors, and which can then be used to generate a much longer include file, with bit masks, offsets, bitfields, structs, and so on as desired. In the case of the LPC1343, the resulting include file is nearly 8 times the size of the register specification, containing a large amount of redundant information that would otherwise either have to be omitted or maintained separately.
The regdefs_genheaders.rb tool will generate a C header for a given part. Run without any parameters to get usage and a list of supported parts.
##lpcprog The LPC1343 microcontroller has a ROM bootloader that emulates a USB mass storage device, showing up as a flash drive with a single firmware file when pin PIO0_1 is held low when it comes out of reset. However, it is particular about the way the firmware file is written, and simply copying the file does not work on OS X and Linux: the OS does not preserve the layout of the file when replacing it. Also, the bootloader will reject the checksums that GCC produces.
This script will fix the checksums, pad the file to the correct length, and write it in a way the bootloader accepts, overwriting the original file instead of replacing the file. It currently works on Mac OS X, Linux and Windows support are partially implemented.
Usage:
Hold PIO0_1 low while plugging/power cycling/resetting the device, and when the device mounts, run:
lpcprog FIRMWARE_BINARY
##usbtools usbtools/usbdesc.rb is similarly a library for specifying USB descriptors with a simple and readable syntax, automatically handling things like computing sizes. An example of its use is in examples/usbtools/usbdesc.rb.
There is a single Descriptor class that takes a descriptor type and a block in which the descriptor fields can be set. An error will be produced if an attempt is made to set a field that doesn't exist for that descriptor type, and the size and type fields are set automatically. Order does not matter, the order in the fields hash of the descriptor type is always used. There are currently no default values, all fields other than bLength, wTotalLength, and bDescriptorType must be specified.
examples/usbcon.cpp and examples/usbcon.rb are simple starting points for working with libusb. For accessing libusb from Ruby, I recommend this libusb gem.