CHAPTER I – INTRODUCT ION ………………………….. ………………………….. …………………… 6 CHAPTER II – PACEMAKE R… [625735]

“POLITEHNICA” UNIVERSITY
TIMIȘOARA
FACULTY OF ELECTRONICS AND
TELECOMMUNICATIONS

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TABLE OF CONTENT

CHAPTER I – INTRODUCT ION ………………………….. ………………………….. …………………… 6
CHAPTER II – PACEMAKE R ………………………….. ………………………….. ………………………. 8
2.1. GENERALITIES ………………………….. ………………………….. ………………………….. … 8
2.2. PACEMAKER SAFETY ………………………….. ………………………….. ………………….. 8
2.3. SIDE EFFECTS OF MAGNETIC FIELD ………………………….. ………………………… 8
CHAP TER III – MAGNETOMETE R ………………………….. ………………………….. …………….. 9
3.1 GENERALITIES ………………………….. ………………………….. ………………………….. …. 9
3.2 MAGNETOMETER OPERATING SYSTEM ………………………….. …………………… 9
CHAPTER IV – CIRCUIT DESIGN ………………………….. ………………………….. ……………… 10
4.1. BLOCK DIAGRAM ………………………….. ………………………….. ………………………. 10
4.2. MOTHERBOARD ………………………….. ………………………….. …………………………. 10
4.2.1. POWER SUPPLY BLOCK ………………………….. ………………………….. …… 10
4.2.1.1.LOW -DROPOUT (LDO) REGULATOR NUME ……………………. 10
4.2.1.2. CARE APRINDE LEDURILE ………………………….. ………………… 10
4.2.1.3. GAS GAUGE NUME ………………………….. ………………………….. .. 10
4.2.2. MICROCONTROLLER ………………………….. ………………………….. ……….. 10
4.2.2.1. EXTERNAL OSCILLATING CIRCUIT ………………………….. …… 10
4.2.2.2. FILTERS AT VCC AND AVCC ………………………….. ……………… 10
4.2.2.3. PDI CONNECTOR ………………………….. ………………………….. …… 10
4.2.3. BLUETOOTH ………………………….. ………………………….. ……………………. 10
4.2.4. EEPROM !!!!! ………………………….. ………………………….. …………………….. 10
4.2.5. USER INTERFACE ………………………….. ………………………….. …………….. 10
4.2.5.1. PUSH BUTTONS ………………………….. ………………………….. …….. 10
4.2.5.2. BUZZER ………………………….. ………………………….. …………………. 10
4.3. DAUGHTERBOARD ………………………….. ………………………….. …………………….. 11
4.3.1. MAGNETOMETER NUME ………………………….. ………………………….. …. 11
4.3.2. LCD NUME ………………………….. ………………………….. ……………………….. 11
CHAPTER V – SIMULATIO NS ………………………….. ………………………….. …………………… 12
CHAPTER VI – TEST PRO TOCOL ………………………….. ………………………….. …………….. 13
CHAPTER VI – CONCLUSI ON ………………………….. ………………………….. …………………… 14
REFERENCES ………………………….. ………………………….. ………………………….. ……………… 15
ANNEXES ………………………….. ………………………….. ………………………….. …………………….. 16

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Chapter I- INTRODUCTION
In this paper it will be present ed the process of electronic design of a magnetometer ,
magnetic field detector . The project is divided in two parts: the first is named “ motherboard ”
and the second one is “ daughterboard ”. The paper treats the steps of the design for each part
having as a result the actual two physical PCBs, and it contains the block diagram, electronic
schematic, printed circuit board layou t, the simulations , and the tests results.
It is divided in seven chapters as follows:
 CHAPTER I represents a short description of the paper, the functionality of the
project, and main objectives that have been followed.
 In the CHAPTER II it is explained what is a pacemaker, its safety and how the
magnetic field can affect it.
 CHAPTER III continue with the main purpose of this paper, the explanations how
the magnetometer can help people with pacemaker , the reason to produce such as
device and at the end its operating system.
 CHAPTER IV is the biggest chapter, containing the detailed informations about
the motherboard and the daughterboard also, explaining the use of every
component and the choosed values, and also the pin descriptions.
 CHAPTER V represen ts the results of the simulations.
 In the CHAPTER VI the test plans are exemplified with their results.
 At the end, in the CHAPTER VII , the conclusions are presented, taking into
account the all the stepts during the design of this project.
The m otherboar d contain s the main blocks like microcontroller, power suppl y, Bluetooth
and the user interface with some push buttons and a buzzer . The processes for this part were
done in a team . Every motherboard will be connected to different daughterboard with specif ic
application, and that’s why it is considered the main part of the project . The choise of the
components used ha d an important role. We have to take into account the electronic
requirements needed for every application in order the motherboard to be compatible with each
daughterboard.

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The d aughterboard is an extension of the motherboard , and it is attached through several
connectors . In this way we created a development board. The d aughterboard designed for my
application contain s a LCD and the magne toresistive digital sensor, which measure the
magnetic field on x, y and respectively z axis .
The selection of the components needed in the schematic, their implementation in the
circuit in the way to result the voltages and the currents such that at the e nd to get the desired
functioning of the device are the main objectives of this project.
The tool that was used to create the electrical schematic and the layout, is the Diptrace,
because it had a free student version with a lot of components and footprint s needed. For the
components which w ere not found in the application, new electrical component and also new
pattern which correspond to it, were created . When all this things were done and the electrical
schematic was finished, the next step was the layout of the printed circuit board. While the
PCB’s were in the manufacturing process, test plans were done. When the printed circuit boards
arrived from the produc er, it had been populated with all the components , needing just to do
the tests and the simulatio ns.
The main reason of designing this type of device, a magnetic field detector, is to alert
people who have cardiovascular implantable electronic devices, CIEDs, such as implantable
cardioverter defibrillator (ICD) or pacemaker, to avoid big electromagnetic f ields. Depending
on the magnitude of the magnetic field, its value it will be displayed on the LCD with a level
bar indicator also, and the buzzer will alert the user if it is in a dangerous zone.
The CIEDs are small devices implanted inside the body, in t he chest area. The pacemaker
is used in order to control the heart to beat at a normal rate and it is intended for the people who
suffer from arrhythmias, abnormal heart rhythms. Typical pacemakers simply can keep the
heart from going to slowly. The ICD is similar to a pacemaker, but it can also senses if the heart
stops and can actually shock the heart. This two devices, pacemaker and ICD, are often
confused, both of them being implanted in the chest and for life, but in fact they are different
devices.

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Chapter II – PACEMAKER
2.1. GENERALITIE S
2.2. PACEMAKER SAFETY
2.3. SIDE EFFECTS OF MAGNETIC FIELD

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Chapter III – MAGNETOMETER
3.1 GENERALITIES
3.2 MAGNETOMETER OPERATING SYSTEM

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Chapter IV- CIRCUIT DESIGN
4.1. BLOCK DIAGRAM
4.2. MOTHERBOARD
4.2.1 . POWER SU PPLY BLOCK
4.2.1.1. LOW -DROPOUT (LDO) REGULATOR NUME
4.2.1.2. CARE APRINDE LEDURILE
4.2.1.3. G AS GAUGE NUME
4.2.2. MICROCONTROLLER
4.2.2.1. E XTERNAL OSCILLATING CIRCUIT
4.2.2.2. FILTERS AT VCC AND AVCC
4.2.2.3. PDI CONNECTOR
4.2.3. BLUETOOTH
4.2.4. EEPROM !!!!!
4.2.5. USER INTERFACE
4.2.5.1. P USH BUTTONS
4.2.5.2. B UZZER

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4.3. DAUGHTERBOARD
4.3.1 . MAGNETOMETER NUME
4.3.2 . LCD NUME

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Chapter V – SIMULATIONS

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Chapter V I- TEST PROTOCOL

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Chapter VI I- CONCLUSION

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REFERENCES

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ANNEXES