Real Time Clock with Temperature Sensor: An Engineering Design Project

Desklib provides past papers and solved assignments for students. This project details the design of a real-time clock with temperature.

DESIGNING A PRODUCT
THAT MEETS
CUSTOMER’S
REQUIREMENTS
Student Name:
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Contents
LO1 Plan a design solution and prepare an engineering design specification in response to a
stakeholder’s design brief and requirements........................................................................................3
a. Produce a design specification from a given design brief..............................................................3
b. Explain the influence of the stakeholder’s design brief and requirements in the preparation of
the design HNC/HND Engineering 3 specification..............................................................................3
c. Produce a design project schedule with a graphical illustration of the planned activities.............3
d. Evaluate potential planning techniques, presenting a case for the method chosen.....................4
e. Compare and contrast the completed design specification against the relevant industry
standard specification.......................................................................................................................5
f. Compare and contrast the completed design specification against the relevant industry standard
specification.......................................................................................................................................6
LO2 Formulate possible technical solutions to address the student-prepared design specification
specifications.........................................................................................................................................8
a. Explore industry’s standard evaluation and analytical tools in formulating possible technical
solutions............................................................................................................................................8
b. Use appropriate design techniques to produce a possible design solution...................................8
c. Apply the principles of modelling/ simulation/prototyping, using appropriate software, to
develop appropriate design solutions...............................................................................................9
d. Evaluate potential technical solutions, presenting a case for the final choice of solution...........11
LO3 Prepare an industry-standard engineering technical design report.............................................14
a. Prepare an industry-standard engineering technical design........................................................14
b. Assess the presented technical design and identify any potential limitation it may have...........14
c. Explain the role of design specifications and standards in producing a finished product............14
d. Identify any compliance, safety and risk management issues present in the chosen solution....15
e. Evaluate the effectiveness of the presented industry standard engineering technical design
report for producing a fully compliant finished product..................................................................15
LO4 Present to an audience a design solution based on the design report and evaluate the
solution/presentation......................................................................................................................18
a. Present the recommended design solution to the identified audience.......................................18
b. Explain possible communication strategies and presentation methods that could be used to
inform the stakeholders of the recommended solution..................................................................19
c. Reflect on effectiveness of communication strategy in presenting the solution..........................19
d. Justify potential improvements to the presented design solution, based on reflection and/or
feedback obtained from the presentation.......................................................................................21
Conclusion...........................................................................................................................................22
References...........................................................................................................................................23
Appendix.............................................................................................................................................24
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List of Figures
Figure 1: Weight graph of client's specification and desired parameter for part selection...................3
Figure 2 Block diagram of RTC...............................................................................................................4
Figure 3 Design flow chart.....................................................................................................................5
Figure 4 Gantt chart of process scheduling............................................................................................6
Figure 5 Critical path analysis of process scheduling.............................................................................6
Figure 6 Schematic of technical design 1...............................................................................................8
Figure 7 Schematic of technical design 2...............................................................................................9
Figure 8 Schematic of technical design 3.............................................................................................10
Figure 9 Schematic of technical design 4.............................................................................................11
Figure 10 Evaluation of technical designs............................................................................................12
Figure 11 Technical design components..............................................................................................14
Figure 12 Contribution of product design steps..................................................................................15
Figure 13 Screen display when RTC is off.............................................................................................16
Figure 14 Screen display for time setting.............................................................................................16
Figure 15 Screen display when switch S1 is pressed............................................................................16
Figure 16 Screen display when time and date is being set..................................................................16
Figure 17 Screen display for erasing EEPROM.....................................................................................16
Figure 18 Screen display while EEPROM being erased........................................................................17
Figure 19 Screen displaying Time, Date, and Temperature.................................................................17
Figure 20 Screen displaying logged data..............................................................................................17
Figure 21 Hardware design of RTC unit...............................................................................................19
Figure 22 Analysis of presentation strategies......................................................................................20
List of Tables
Table 1 Comparison of Real Time Clock modules..................................................................................6
Table 2 Feedback questionnaire..........................................................................................................20
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LO1 Plan a design solution and prepare an engineering design specification
in response to a stakeholder’s design brief and requirements.
a. Produce a design specification from a given design brief
 Real Time Clock (RTC) with Temperature
 RTC display day, time, and temperature
 Use of Arduino or microcontroller for RTC designing purpose
 A temperature sensor to temperature input
 LED to display readings of RTC (Lee, 2018)
b. Explain the influence of the stakeholder’s design brief and requirements in the
preparation of the design HNC/HND Engineering 3 specification.
Specification weight and desired parameter for selection of parts for building amplifier rated
on a scale of 1 – 50.
RTC Module Temperature Sensor Microcontroller/Arduino LED Display
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35
40
45
50 47
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35
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40 39
42 40
45
35
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40
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Weightage of Specification Durability Compatibility
Reconfiguration Assembling
Figure 1: Weight graph of client's specification and desired parameter for part selection
c. Produce a design project schedule with a graphical illustration of the planned
activities.
When I studied project description, I have devised the possible target specification. I will
select final design after evaluating technical solutions that will devise to reach a final
technical design.
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 For RTC module: DS3231 and DS1307
 For controller module: Arduino or Microcontroller
 For temperature sensor: LM35, Integrated temperature compensated crystal oscillator
(TXCO), or DS18B20
 For display: LCD, TFT, or LED
d. Evaluate potential planning techniques, presenting a case for the method
chosen.
Design process of an RTC unit is consist of five stages:
1. Selecting a Real Time Clock (RTC) module
2. A temperature sensor to take temperature input
3. Use of microcontroller or Arduino for design RTC unit
4. An LCD to display day, time, and current temperature (Bi, 2017)
4.1 Real Time Clock block diagram
Considering design stages of RTC, figure 2 illustrate the block diagram of amplifier.
Figure 2 Block diagram of RTC
4.2 Design flow chart
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Figure 3 Design flow chart
e. Compare and contrast the completed design specification against the relevant
industry standard specification.
My first task in design process is to meet with client to get an understanding of desired
product. Requirement is gathered about a product, discuss implications of requirements.
When requirements fully understood the process of developing different design concepts will
be started. These design concepts will be evaluated on basis of certain parameters to select a
final design. When final design selected, its prototype modelling takes place. After
developing, prototype testing will perform keep in view different applications. Suggested
improvement implements on the basis of feedback, and this process will continue to test
design till it satisfies desired requirement. When requirement is satisfied, a final meeting with
client conducted. This meeting present final product and elaborate its design working (Oh,
2015).
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Figure 4 Gantt chart of process scheduling
Figure 5 Critical path analysis of process scheduling
f. Compare and contrast the completed design specification against the relevant
industry standard specification.
Table 1 Comparison of Real Time Clock modules
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Device Power Supply Communication
Speed RAM Battery
MCP79400 1.8V ~ 5.5V 400 kHz 64 byte 3V
DS1307 5.5V 400 kHz 56 byte 3.5V
DS3231 5.5V 400kHz  3.3V
PCF8563 1.0V ~ 5.5V 400kHz  
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LO2 Formulate possible technical solutions to address the student-
prepared design specification specifications.
a. Explore industry’s standard evaluation and analytical tools in formulating
possible technical solutions.
After extensively analyzing requirements, next thing is to develop technical designs for real-
time clock. In this regard, I have design 10 designs and 4 designs are considered for final
design development. While developing a technical solution for project, client requirement of
real-time clock design followed completely. Connection wires and breadboard are generic in
all technical designs (Li, 2017).
b. Use appropriate design techniques to produce a possible design solution.
In this technical design, I have selected Arduino UNO, DS3231 RTC, OLED, and LM35
temperature sensor. In start, I have connected OLED with Arduino through SPI
communication. After connecting OLED, DS3231 connected with Arduino using I2C
communication. For I2C communication, DS3231 connected through SDA and SCL pins
with Arduino. To connect LM35 temperature sensor, its left pin connected with 5V, middle
pin A0, and right pin to ground of Arduino. When circuit for real-time clock assembled then
first I did is initialize SPI communication. After initializing SPI communication, other
variables are also initialized like an LM35 temperature sensor. Temperature sensor LM35 is
declared as input pin because Arduino takes temperature as an input. Next step is to
command DS3231 and OLED to commence communication with Arduino. When
communication started between Arduino and selected components, results of designed project
are displayed on OLED. These results are time, date, and temperature. Figure 6 illustrates the
schematic of design 1.
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Figure 6 Schematic of technical design 1
c. Apply the principles of modelling/ simulation/prototyping, using appropriate
software, to develop appropriate design solutions.
Second technical design considered for project consisted of Arduino Due, DS3231 RTC, and
for display 3.2-inch colour TFT is used. The 3.2-inch colour TFT is connected to Arduino in
first phase, the TFT display has 480x320 resolution, SD card adapter, and 3.3V regulator.
Next, the DS3231 module is connected with Arduino Due using I2C communication, which
is possible through SDA and SCL pins of module. For temperature readings, in this design, I
am using DS3231 integrated temperature compensated crystal oscillator (TXCO) rather than
separate temperature sensor. After assembling all parts of real-time clock, SPI
communication and other variables are initialized. Integrated TXCO of DS3231 use as input
for Arduino for temperature readings. Communication between DS3231 and TFT display is
commenced and clock project results started to display on TFT screen. The TFT screen
displays, time, date, current temperature, and max and minimum temperature. Figure 7
illustrates the schematic of design 2.
Figure 7 Schematic of technical design 2
1.1 Technical design 3
Technical design 3 consists of following components: 1) DS3231 RTC, 2) 16x2 LCD
module, and 3) Arduino Mega. First thing is to mount LCD on Arduino. After that connect
RTC module through I2C communication, for connection purpose RTC module’s SDA and
SCL pins are used. For temperature input, RTC module’s integrated temperature
compensated crystal oscillator (TXCO) is utilized instead of a separate temperature sensor.
All these components will have mounted on a breadboard and powered up. After mounting
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components, first phase is powering up LCD then initialize SPI communication and other
variables. When SPI communication initialized, RTC module and Arduino start
communication with each other. This will result in display of time, date, and temperature on
LCD screen. Figure 8 illustrates the schematic of design 3.
Figure 8 Schematic of technical design 3
1.2 Technical design 4
The 4th technical design I considered consist of Arduino UNO, DS3231 RTC module, and
ST7735 1.8-inch colour TFT. The 1.8-inch colour TFT is connected to Arduino in first phase
of design then RTC module connected for I2C communications. This I2C communication is
possible through SDA and SCL pins of RTC module. The integrated temperature
compensated crystal oscillator (TXCO) is used to take input readings on temperature. The
design setup is assembled and now is the time to power it up. First TXCO will declare as
input for temperature readings then initialize SPI communication and other related variables.
In second phase RTC commanded to commence communication with TFT. When this
communication commences, TFT screen started to display day, time, date, current
temperature, and minimum and maximum temperature. Figure 9 illustrates the schematic of
design 4.
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Figure 9 Schematic of technical design 4
d. Evaluate potential technical solutions, presenting a case for the final choice of
solution
In this section, evaluation of technical designs carried out using certain parameters. This
evaluation activity helps in developing final design for project. On the basis of evaluation,
some components will be selected from technical designs mentioned in previous section and
some new parts will be added if required. All parameters will be rated on a scale of 1 – 10, 1
being lowest and 10 being highest. Each evaluation carries out by keeping in mind technical
designs and client’s requirements.
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