How time flies … (and there’s a reason: we’ve moved to a new apartment).
I’ve started working on JeeH again (which is now at version 7). There have been several substantial changes, affecting all parts of the project:
-
The multi-tasker is now event-based. There is a single stack, where higher-priority tasks can interrupt and preempt running code. That code is then resumed when the task is done. A task cannot suspend itself, it can only run to completion (read: “return”). In a way, this design feels more like event-based programming than multi-threading, but with immediate IRQ handling.
-
All I/O goes through an
ioRequest()method, which takes an array ofIoReqstructs and processes each one in sequence. This solves the way I2C works with “restarts”, i.e. performing a read right after a write, while still supporting an (optional) asynchronous model. -
The
Devtype wraps driver requests and deals with I2C addressing and SPI bus select pins. It also addsread(),readReg16(),write(), etc wrappers for easy access to registers and for configuring attached I2C and SPI devices. -
The same
ioRequestmechanism is also used by UART drivers.
A brand new feature I’m working on: running device drivers on the host for sensors, displays, etc: anything attached to the µC via an I2C or SPI bus. The µC uses a “bridger” application for this: it accepts requests from the host PC over serial, performs each request, and sends back the results. This speeds up the development of µC-specific device drivers by omitting all cross-compiles and uploads-to-flash. It’s not ready yet, but initial results show that this is feasible (and indeed much faster).
There are also a few other major JeeH design and API changes in the pipeline.
Anyway, I’m very happy to get back to hacking on JeeH …