PB171 – Semestral task description (spring 2021)
The semestral task is the only mandatory requirement to pass this subject. The task consists
of two parts. The first part contains several schematics of the hardware you have to design.
The second part is about implementation of API (application programming interface) for the
selected peripherals.
1 General information
• The task will be submitted as one ZIP archive to the corresponding folder at IS MU. If
you use a repository, you can simply compress and upload the whole repository. The link
to the folder at IS MU:
https://is.muni.cz/auth/el/fi/jaro2021/PB171/ode/111395642/
• I recommend to use a repository during the semester and share the temporary results
with me. We can avoid fatal mistakes and I have a feedback from you during the whole
course.
• If I find any fatal mistake in the final submission, I will return it to you for a correction.
• After successful submission I will ask you for a defense as an online meeting. This defense
must be completed before the end of the examination period. You will receive your mark
immediately after your defense.
2 Hardware part
Please submit your electrical schematics as a PDF document. The PDF should contain images
of all your schematics and every image should be commented about what is inside each
schematics and why.
2.1 Abbreviations
• CPU – Your selected microcontroller approved by me. If you work with the PCB from
the faculty, you should use PIC18F44K22.
• LED – Light-Emitting Diode
• IO pin – Input/output pin
• GPIO pin – General purpose input/output pin
• AD converter – Analog to digital converter
• DA converter – Digital to analog converter
• RGB LED – LED with red, green and blue channel
• PWM – Pulse Width Modulation
• UART – Universal asynchronous receiver-transmitter (specific peripheral of the CPU)
• I2C – Inter-Integrated Circuit or Two Wire Interface (specific peripheral of the CPU)
• SPI – Serial Peripheral Interface (specific peripheral of the CPU)
• 3S Li-Ion battery – Li-Ion battery consists of three cells connected serially
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2.2 Basic schematics
1. Draw schematics of the circuit with one LED driven by the CPU. The power supply is
5 V. Please specify a link to the datasheet of the used LED and the used CPU.
2. Draw schematics of the circuit with one switch and one button connected to the CPU as
two input devices connected to two separate pins.
3. Draw schematics of the circuit with one button and one LED connected to any IO pin on
the CPU. If the IO pin is set as output, the LED is driven by the CPU. If the IO pin is
set as input, the CPU is able to read the state of the button and the LED indicates the
state of the button, too.
4. Draw full schematics of the circuit with one LED driven by the CPU, one button connected
as an input device to the CPU, power supply within the range 7 V-12 V, and all the passive
components required by the CPU manufacturer.
5. Draw schematics of the circuit with one potentiometer connected as an analog input to
the CPU. The CPU usually has several AD converters, you can use any of them.
6. Draw schematics of a thermistor connected to any AD converter on the CPU. The CPU
should be able to measure the temperature of the thermistor. Please specify a link to the
selected thermistor.
7. Draw schematics of the circuit with power input 7 V-12 V and one CPU. The CPU is able
to measure the input voltage on its AD converter input. Please note that the CPU runs
at lower voltage than the power supply and the AD converter cannot handle 12V directly.
Please specify a link to the datasheet of every used component.
8. Draw schematics of the circuit with one RGB LED driven by the CPU. The CPU is able
to set the brightness of every channel by PWM.
2.3 Schematics with high power consumption
9. Imagine that you just bought this servomotor:
https://hobbyking.com/en_us/turnigytm-tgy-50090m-analog-servo-mg-1-6kg-0-08sec-9g.html
You want to test the communication between the servo and your CPU. Draw a connection
circuit between the servo and the CPU.
10. Imagine that we are building a small walking robot with 6 legs. Each leg needs 3 servos.
You can find an example in this video:
https://youtu.be/ull5TyOnoFo
Draw full schematics of the circuit with one 3S Li-Ion battery (or two batteries if needed),
one CPU and 18 servos. You do not have to draw all the 18 servos, the most important
part is how you solve the power supply.
11. Imagine that you just bought this DC motor:
https://www.tme.eu/cz/en/details/sf-rob-11696/dc-motors/sparkfun-electronics-inc/rob-11696/
You want to control it by CPU using PWM. Draw schematics of a connection between
the CPU and the motor.
12. Change the previous schematics to allow to control the motor rotation in both directions.
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13. Imagine that you have this motor:
https://hobbyking.com/en_us/turnigy-aerodrive-sk3-2826-980kv-brushless-outrunner-motor-1.html
with this speed controller:
https://hobbyking.com/en_us/blheli-s-20a.html
Draw schematics of the connection between your CPU used as the PWM source for this
speed controller connected to this motor. Include the battery and provide a link to a
suitable one.
2.4 Schematics of the peripherals
14. Draw schematics of this FTDI chip:
http://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT232R.pdf
connected to the PC via USB and to your CPU via UART.
15. Imagine that you have this absolute orientation sensor:
https://cz.mouser.com/datasheet/2/783/BST_BMX055_DS000-1509552.pdf
Draw schematics of a connection between this sensor and your CPU using SPI interface.
16. Change the previous schematics to I2C interface.
17. Imagine that you have two CPUs. The distance between them is 20 meters. Draw
schematics of the UART connection between them.
18. Draw schematics of a connection between an SD card and your CPU. You can select
between SPI or SDIO interface.
3 Software part
The software API should be submitted as a full project with demo setup() and loop()
functions. I have to be able to compile your solution and upload it to the real microcontroller.
If you use the PCB from the faculty or if you use the remote connection to the server, you
can find some basic information including a template for your work here:
https://github.com/bsaid/PB171
You will implement the selected part of the Arduino API for your CPU as shown in the
example here:
https://github.com/bsaid/PB171/tree/main/ArduinoExamplePIC.X
Please implement the functions below. Their documentation is available here:
https://www.arduino.cc/reference/en/
3.1 Platform independent functions
• bit()
• bitClear()
• bitRead()
• bitSet()
• bitWrite()
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• highByte()
• lowByte()
3.2 Basic functions
• pinMode()
• digitalWrite()
• digitalRead()
• analogRead()
• analogWrite()
• delay()
• delayMicroseconds()
• millis()
• micros()
3.3 Class for communication with UART interface
Please follow the documentation here:
https://www.arduino.cc/reference/en/language/functions/communication/serial/
• available()
• availableForWrite()
• begin()
• end()
• flush()
• parseInt()
• peek()
• print()
• println()
• read()
• readBytes()
• write()
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3.4 Advanced peripherals
Please select one of the following classes (ideally everybody different one) and implement it:
• https://www.arduino.cc/en/Reference/EEPROM
• https://www.arduino.cc/reference/en/libraries/servo/
• Design your own API to control the onboard display. You can find your inspiration, for
example, here: https://www.arduino.cc/en/Reference/LiquidCrystal
• https://playground.arduino.cc/Code/StopWatchClass/
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