Libraries
Background
The Tollos supervisor has limited support for peripheral devices at present, but does include a number of features that simplify application development:
- Tollos is written in C. All the source code is included; the Tollos source code is royalty free and licensed for any use (see the download page).
- Interfaces are provided for
- on-board LEDs
- digital (general purpose) I/O pins, including per-pin interrupt handling
- I2C bus devices
- screen drawing amd the DOGXL LCD
- interrupt vectors
- UART serial communications
- watchdog reset time
- accelerometers and gyroscopes
- application initialization and tick timing.
- A debug module provides communication with a serial terminal (or a terminal emulator running on a host computer); strings can be written to the terminal using debugf (a subset of printf), and characters can be read from the terminal.
- Tollos is quite small; the binary file for a ‘hello world’ application using debugf uses fewer than 4,400 bytes.
- The Tollos sysQuery function lets you determine
critical resource usage:
- recent and maximum tick execution times (giving processor usage)
- stack space and maximum usage
- whether the last reset was abnormal (watchdog or brownout).
- The Tollos libraries and link scripts support the necessary GCC options so that only functions which are used are included in an application’s binary file.
- A simple script is included for building Tollos libraries and the sample application using either drag-and-drop or command-line commands on Windows; it should be easily convertible to other scripting languages such as REXX or sh.
- All Tollos source code compiles clean with the GCC -c99 and -pedantic options and also conforms to strict aliasing requirements.
DOGXL LCD (click to enlarge)
Other libraries for higher-level access to GPS and other sensors, and for other boards and devices, are currently being written for Tollos.