Technical Manual
Table Of Contents
- 1. Introduction
- 2. Hardware
- 3. The A431 Radio Module
- 3.1. About the A431 Radio Module
- 3.2. Functional description
- 3.3. Manufacturing Issues
- 3.3.1. Marking and labeling issues
- 3.3.2. Alignment Range and Switching Range
- 3.3.3. Tuning Procedure
- 3.3.4. Setting Up the Default Parameters
- 3.3.5. Definitions
- 3.3.6. Test Equipment Settings
- 3.3.7. Trimming Elements
- 3.3.8. Adjusting the Receiver Front End
- 3.3.9. Adjusting the VCOs
- 3.3.10. Adjusting the Crystal Reference
- 3.3.11. Checking the Receiver Parameters
- 3.3.12. Checking the Transmitter Parameters
- 3.3.13. Data Transfer Check
- 3.4. PCB Parts Placement
- 3.6. Frequency Reference Specifications
- 3.7. A431 Module’s Photographs
- 4. Software
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4. Software
4.1. Short Description
The software is written entirely in C. It consists of a collection of standard C library
functions, a pre-emptive multitasking operating system (CMX) offering basic config-
uration and administration functions (including a command line terminal on a serial
port), and the application software itself, which assures the desired functionality of
the device.
4.2. Tasks
Following tasks are currently implemented:
• Command Line Interpreter Task
• Radio Task
• Memory Management Task
• Real Time Clock (RTC) Task
The system usually remains in sleep mode. Each 0.5 seconds, an interrupt is gener-
ated by the local 32.76 Khz crystal oscillator. This wakes up the processor and acti-
vates the CMX RTOS, which allows all active tasks to perform their functions. After
all the tasks have finished their jobs, CMX brings the system back to sleep. The 0.5
seconds interrupt routine is also used as time reference for the RTC task.
In parallel to the normal, regular operation of the CMX, the system responds to the
pulse counter interrupts (they are generated by four inputs on the microcontroller