8052 to Serial Interfacing

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Microcontroller-based Data Logger with RS232 Interface

* DECLARATION of plagirism

*I declare that all material in this submission e.g. thesis/essay/project/assignment is entirely my/our own work except where duly acknowledged.

*I have cited the sources of all quotations, paraphrases, summaries of information, tables, diagrams or other material; including software and other electronic media in which intellectual property rights may reside.

*I have provided a complete bibliography of all works and sources used in the preparation of this submission.

*I understand that failure to comply with the Institute’s regulations governing plagiarism constitutes a serious offence.

Student Name: (Printed)Miro Konttinen

Student Number(s):c00164647

Signature(s):____________________________________________ Date:____________________________________________

------------------------------------------------------------------------------------------------------- Please note:
a) * Individual declaration is required by each student for joint projects. b) Where projects are submitted electronically, students are required to type their name under signature. c) The Institute regulations on plagiarism are set out in Section 10 of Examination and Assessment Regulations published each year in the Student Handbook. *

Table of contents
DECLARATION of plagirism3
Table of contents4
1General introduction5
1.1Project specifications5
1.2Motivations and rationales6
2Literature research6
3Full description of project (Development)7
3.1.18052 & Crystal7
3.1.3LED driver9
3.1.4Serial interface10
4Preformance evaluation11

General introduction
The aim of this project is to get a microcontroller to read an analog signal with specific intervals controlled with a PC by sending certain letters to the microcontroller via the serial port, then stores the values to memory and when given a specific command uploads the logged data to the computer. The chip won’t have any other controlling methods other than the serial port connected with the PC. The values are displayed with the PC so no display is needed. Some status LED’s are connected to the microcontrollers pins to show basic info like current logging interval and is the chip doing something or not. To get the chip to do all of this it needs auxiliary component around it like and ADC for signal conversion, an interface chip for the serial port and a LED driver for the LED’s The programming is done in C51. The difference between C & C51 is that it has some extra command that the 8052 uses like SBIT. This is a single bit operation that is not possible to do with normal C. Project specifications

The Microcontroller used for this project is an 8052 with and external crystal of 11,0592MHz which is a common crystal when using the serial port for the simple reason that it makes the math easy. To read the analog signal it has to be converted to digital form. An Analog to digital converter chip is used called ADC0804 in free running mode. This just means that the ADC converts the values constantly. The intake of the values is controlled with the microcontroller. For interfacing the 8052 with a computer an interfacing chip is needed called MAX232. This converts the voltage levels so that both the PC and the microcontroller understand each other. The process can be monitored by indicator LED’s. Indications for the Interval of samples taken and the current Operation mode are shown with the LED’s. The LED’s are connected to the 8052 via a SN7406 driver. Controlling the LED’s without the driver wouldn’t work properly due to current restrictions on the 8052. Sinking was an option but the current limits would be too close to comfort.

Motivations and rationales
For a person who doesn’t have a lot of experience in programmable...
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