The intermediate report doesn't need to be a long book. It should focus on the important aspects. It is also a basis for the final report, which should reuse most of its content. Overall number of pages shall not exceed 12. The report should be structured as follows:

1. Introduction

Problem to be solved, objectives of the project, etc.

2. Overall Architecture
System-level description, explaining the use cases and roles of the main components (e.g., Sensor/Actuator node, Cloud Server, Mobile App), as well as the data flows between them.

3. Performance requirements
Performance requirements of the system, if any (e.g., delay bounds, required message rates, required message sizes, required communications range, autonomy and maintenance requirements, required precision/resolution of the data, etc.). Can be based on specifications of similar commercial solutions.

4. Sensor/Actuator Node
4.1. Hardware
Component list and brief description, as well as details on how the components are connected (e.g. Fritzing diagram). 
4.2. Software
Description of the processing node's algorithm (flowcharts or state machine diagrams, together with a complementary text explanation are welcome), as well as message types/formats.

5. Cloud Server
Description of the platform where it is to be deployed, expected offered services/API's, etc.

6. Mobile App
Description of the functionalities to be offered and respective activity layouts, special frameworks and libraries that will be used, etc.

7. Conclusions
Overall conclusions of the project at this stage, such as the status of development, additional aspects not addressed in the previous sections, etc.

As to the final report, The final report should include the contents that were requested for the intermediate report, corrected and completed in order to reflect the final status of the project. The final report shall not exceed 15 pages!!!
Two extra sections must be included before the Conclusions:

7. Results of the Tests
Results of functional and/or performance tests of the system.

8. Changes relative to the Intermediate Report
Indicating the relevant changes that were introduced, identifying the respective sections that should be checked.