Ανακοινώσεις μαθήματος Ενσωματωμένα Συστήματα

Evaluation (winter semester 2025-2026)

Fri, 13 Feb 2026 11:29:49 +0300

Dear All,

after considering your effort during the winter semester, I summarize next.

One key point in your work, reporting, and overall demonstration is to present

clearly your methodology, evaluation/testing, weak and strong points/features

based on criteria you set and/investigate.

For example, regarding the project, you could expore different methods using

a single or multiple threads, mutexes for resource protection or light-weight locks,

circular of fifos in DRAM or is SRAM, different methods of representing sensor values,

different compression techiques, and related tradeoffs.

	Labs	Exams	Project	Final
	`(25%)	`(50%)	`(25%)
ΤΗ20052	7.5	6.5		5.125
ΤΗ20010	8	8.7	4	7.35
ΤΗ20056	9	9.5	4.5	8.125
ΤΗ20175	9	9.5	9	9.25
ΤΗ20156	7	9	9	8.5
ΤΗ20049
ΤΗ20481	5	8		5.25
ΤΗ20330	9	9.5	9	9.25
ΤΗ20286
ΤΗ20391	9	9	9	9
ΤΗ20591	9	8	7.5	8.125

tp4356		6	7.5	6.75
tp4969		1
tp4941		2
tp5061		2
tp4703		1
tp5052		0
tp4904		8.5	7	7.75
tp4900		7.5
tp4877		5	7	6
tp4543			7	3.5
tp4860			5	2.5

ΕΡ2337	9	8	8	8.25
ΕΡ2257	10	9.5	9.5	9.625
ΕΡ2330	8	8.5	8	8.25

Lab 10/12/2025

Wed, 10 Dec 2025 08:42:49 +0300

Dear All,

the goal of this Lab is to test/experiment with methods to optimize the

performance (+energy efficiency) of an embedded application, such as of the previous Lab.

1. Change the previous application (collecting and sending a batch of temperatures),

by placing the application in the internal SRAM, and calculate the difference from the original application

in the external DDR RAM.

2. change the temperature values from float to int and calculate the total time now.

What if instead of integer of 4 bytes : from 4 bytes an integer use just the 2

and pack two values in one integer, the receiving thread should do the opposite.

(https://stackoverflow.com/questions/66933656/c-c-compressing-integer-to-short-and-decompressing-to-integer)

3. use some other simple compression method, e.g.:

https://github.com/fast-pack/LittleIntPacker

have a nice day

George.

Measuring elapsed time in Zedboard (and FreeRTOS)

Wed, 26 Nov 2025 10:25:52 +0300

Method 1:

by using the Global timer/counter:

a) https://adaptivesupport.amd.com/s/question/0D52E00006hpU6USAU/time-measurement-in-sdk?language=en_US

b) https://forums.freertos.org/t/measure-time-within-a-task-with-xtaskgettickcount/7401

Method 2:

by using the XScuTimer, such as the following example:

static void prvRxTask( void *pvParameters )
{
int message = 0;
int Status;
volatile u32 CntValue2 = 0;
XScuTimer Timer;
XScuTimer_Config *ConfigPtr;

ConfigPtr = XScuTimer_LookupConfig(TIMER_DEVICE_ID);

Status = XScuTimer_CfgInitialize(&Timer, ConfigPtr, ConfigPtr->BaseAddr);
if (Status != XST_SUCCESS) {
print("ERROR\n");
return;
}

XScuTimer_LoadTimer(&Timer, TIMER_LOAD_VALUE);

/* Block to wait for data arriving on the queue. */
xQueueReceive(xQueue, /* The queue being read. */
&message, /* Data is read into this address. */
portMAX_DELAY ); /* Wait without a timeout for data. */

XScuTimer_Start(&Timer);

CntValue2 = XScuTimer_GetCounterValue(&Timer);

XScuTimer_Stop(&Timer);
xil_printf("Elapsed: %d ticks\r\n", TIMER_LOAD_VALUE - CntValue2);
printf("Elapsed: %f micro seconds\r\n", (TIMER_LOAD_VALUE - CntValue2)/(float)333);
}

Lab 26/11/2025

Tue, 25 Nov 2025 23:25:45 +0300

Dear All,

please use the freertos c code example you can find in lab folder.

step 1.

create a global array of 100 floats with random values - representing temperatures - ranging from -10 to 30 .

step 2.

create (or modify) a transmit thread that sends 20 values to a receiving thread.

step 3.

the receiving thread computes the average of these 20 values and the total average (and prints it)

step 4.

the receiving thread uses the least squares method to compute the trend,

according to this example: https://stackoverflow.com/questions/5083465/fast-efficient-least-squares-fit-algorithm-in-c

and print one prediction after 100 values (assuming 1 value will be captured per sec).

Best regards,

George

Project (deadline end of Jan 2026)

Mon, 24 Nov 2025 09:47:36 +0300

Dear All,

the course project can be found in https://eclass.hmu.gr/modules/document/file.php/ECE292/Projects/projectwinter2025.pdf

More details to discuss on Wednesday.

Best regards,

George Kornaros

Lab 19/11/2025

Wed, 19 Nov 2025 06:57:47 +0300

Dear All,

please check the following file for today's Lab (19/11/2025):

Lab8_tempsensor.pdf

You should use the previous platform, with the leds,buttons,switches,

(maybe also the OLED display if you prefer to display the temperature in the OLED display).

More details later in the Lab,

Best regards,

George

Elevator simulation on board

Wed, 05 Nov 2025 08:39:37 +0300

Dear All,

Extra cases:

- the user may press the central button to freeze the elevator, then the led should blink with a duration of 100 ms,
and the up or down button should un-freeze the elevator (which maintains its previous schedule, i.e. it will not
change direction)
- if multiple switches are turned on during the movement the initial target should be maintained
- if multiple switches are turned on before the elevator starts to move, then the closest one is considered.

You may use the hardware time, or functions usleep(), sleep().

George.

Important- Project evaluation

Wed, 12 Feb 2025 19:03:53 +0300

Dear All,

in order to evaluate your report (uploaded at eclass),

it is needed for you to upload your Vivado project (maybe at some external public repository).

Otherwise, it is not possible to assess your report, without the possibility for me to test your code.

Best regards,

George

Lab 11/12/2024

Tue, 10 Dec 2024 20:35:31 +0300

Dear All,

please use the freertos c code example you can find in lab folder.

step 1.

create a global array of 100 floats with random values - representing temperatures - ranging from -10 to 30 .

step 2.

create (or modify) a transmit thread that sends 20 values to a receiving thread.

step 3.

the receiving thread computes the average of these 20 values and the total average (and prints it)

step 4.

the receiving thread uses the least squares method to compute the trend,

according to this example: https://stackoverflow.com/questions/5083465/fast-efficient-least-squares-fit-algorithm-in-c

and print one prediction after 100 values (assuming 1 value will be captured per sec).

Best regards,

George

Lab 27 Nov 2024

Mon, 25 Nov 2024 08:30:49 +0300

Dear All,

please prepare the next Lab in order to test the application with the OLED display

of the board. You may find code/instructions in the file Lab_withOLED.zip

After that, you may test another software project based on the example code

based on the freeRTOS (also in eclass).

For any additional information please contact me by email, or tomorrow during the class.

Best regards,

George.

Lab 13 Nov 2024

Tue, 12 Nov 2024 20:46:36 +0300

Please have a look at lab8_tempsensor.pdf

This is a quite simple application to test a temperature sensor ( which is already integrated on the board).

G.K.

Lab - Simple Elevator

Sun, 10 Nov 2024 08:36:38 +0300

Dear All,

Develop a new application project in SDK, called LabXX_elev, (XX stands for your AM) to simulate
a simple elevator.
- use the leds to indicate the current floor (the righmost represents the ground floor)
- use the switched to indicate the floor tha the user wishes to move to
- use the up and down button to trigger the led (the elevator) to move
- the duration of the led turned on is 1 sec
Extra cases:
- the user may press the central button to freeze the elevator, then the led should blink with a duration of 100 ms,
and the up or down button should un-freeze the elevator (which maintains its previous schedule, i.e. it will not
change direction)
- if multiple switches are turned on during the movement the initial target should be maintained
- if multiple switches are turned on before the elevator starts to move, then the closest one is considered.

You may use the hardware time, or functions usleep(), sleep().

George.

Lab 30 Oct 2024

Tue, 29 Oct 2024 20:01:50 +0300

Dear All,

please check the lab5_gr.pdf and the corresponding template lab5.c

focusing on using the hardware timer.

Please also check an example with interrupts (called lab5_xscutimer_int.c).

The goal is to achieve a moving led from end to end, with 10-100ms delay.

George Kornaros

Using a single cable for ZedBoard for programming anf UART debugging

Wed, 16 Oct 2024 10:33:29 +0300

Οδηγίες Zedboard jtag-uart

SDK:

Right click "Board Support Package Settings"
Overview->standalone
stdin : ps7_coresight_comp_0
stdout : ps7_coresight_comp_0

Program FPGA (download bitstream)

c)
TestApp right click
Run As -> Launch on Hardware (System Debugger)

d)
Sto xsdb (System Debugger)

connect -host localhost -port 3121
targets
targets 2
jtagterminal -start

Video - μάθημα 14 Δεκεμβρίου 2023

Thu, 14 Dec 2023 11:14:59 +0300

https://drive.google.com/file/d/1YH2j3GrZTdE852a37_IuU2xEATID96wZ/view?usp=sharing

State machines in C

Fri, 08 Dec 2023 10:23:34 +0300

Καλημέρα σας,

ενημερωτικά, για ανάπτυξη δομημένου, robust code για το προτζεκτ σας,

θα βρείτε σχετικές πληροφορίες και code templates για state machines in C,

1. https://github.com/endurodave/C_StateMachine

2. https://www.controleng.com/articles/finite-state-machine-for-embedded-systems/
3. https://aticleworld.com/state-machine-using-c/

Καλή συνέχεια,

Γιώργος

Video - μάθημα 7 Δεκεμβρίου 2023

Fri, 08 Dec 2023 10:20:07 +0300

https://drive.google.com/file/d/1juamstQ4goYXrM0irzQVGpeZ0z0erlub/view?usp=sharing

Lab 6 Dec 2023

Wed, 06 Dec 2023 07:13:31 +0300

Καλημέρα,

Στόχος: εξοικείωση με FreeRTOS (από την version Vivado 2015.4 και μετά).

Στο Vivado του 2015.2 δεν υπάρχει ενσωματωμένο στο SDK to FreeRTOS.

Ενσωματώθηκε στην έκδοση 2015.4.

1. Ξεκινήστε από το προηγούμενο εργαστήριο με το OLED display

(αν δεν λειτουργεί το δικό σας υπάρχει διαθέσιμο ένα Lab έτοιμο να σας μεταφέρω)

2. Δημιουργήσετε στο SDK ένα νέο application lab6Dec, όπου προσέξτε αντί standalone να επιλέξετε freeRTOS
(version 2015.4)

3. Το παράδειγμα hello δημιουργεί 2 threads που στέλνει το ένα στο άλλο ένα μήνυμα και τυπώνεται από
το Rx thread.

4. Προσθέσετε να τυπώνεται ένας χαρακτήρας στο OLED display από το Rx thread.

5. Προσθέσετε έναν μετρητή (μεταβλητή int) στο Rx thread και όποτε έρχεται μήνυμα να στέλνετε τον μετρητή
στο OLED display (υπενθύμιση) χρειάζεται μετατροπή από int se string)

6. Δημιουργία ενός software timer (ακριβής timer αν και όχι με hardware timer, με βάση το FreeRTOS):
Προσθέσετε στο παράδειγμα σας τον κώδικα από το
https://github.com/LogicTronix/FreeRTOS-Development/blob/master/Creating-Software-Timer/freertos-soft-timer.c
ώστε να εκτυπώνεται ένα μήνυμα κάθε 1 sec.
Θα πρέπει να βλέπετε ένα μήνυμα από τον timer και ένα από το RX thread εναλλάξ.
Αλλάξτε τον timer se 0.5 sec. Τώρα πρέπει να βλέπετε 2 μηνύματα του timer και 1 του Rx.

Καλή σας μέρα,

Γιώργος

Video - μάθημα 30 Νοεμβρίου 2023

Thu, 30 Nov 2023 11:20:20 +0300

part1:

https://drive.google.com/file/d/1nQCt6BQHZ0GpE13MDs-ehc8eI8ZW2NkJ/view?usp=sharing

part2:

https://drive.google.com/file/d/1pLgXSgJMO8xMNFJo8yts1IZSt4_2ISta/view?usp=sharing

Video - μάθημα 23 Νοεμβρίου 2023

Thu, 23 Nov 2023 11:59:24 +0300

https://drive.google.com/file/d/17cM5Twsho7HWDF7OO34UTL5t-txMGQkb/view?usp=sharing

Video - μάθημα 16 Νοεμβρίου 2023

Thu, 16 Nov 2023 11:56:39 +0300

https://drive.google.com/file/d/12ccsRsMCj7WienFk-P8LgCA-GiitDJpe/view?usp=sharing

https://drive.google.com/file/d/1Qhn14dXWCmLrT3RigaF1lRmpL9WtrOhd/view?usp=sharing

Video - μάθημα 2, 9 Νοεμβρίου 2023

Thu, 09 Nov 2023 10:18:28 +0300

https://drive.google.com/file/d/1RoCW9HFn0yZJ5bXYxyiO6qenI2w8yZsc/view?usp=sharing

https://drive.google.com/file/d/1eKquyv1hr2VK9DrNnhkmZhDRMBNggApr/view?usp=sharing

Χρονομέτρηση / Profiling ενός προγράμματος

Wed, 08 Nov 2023 10:43:33 +0300

Χρονομέτρηση / Profiling ενός προγράμματος

Έστω ότι έχουμε τις ακόλουθες δηλώσεις
#define N 100
int arrA[N];
int arrB[N];
int arrC[N];

Κάνετε μια συνάρτηση vectoradd( ) που υπολογίζει το:
C[i] = A[i] + B[i], i=0,..,n

(εφόσον τους έχετε αρχικοποιήσει σε τυχαίες ή ακολουθιακές τιμές)

α)

Με χρήση του XScuTimer μετρήσετε πόσους κύκλους ρολογιού χρειάζεται

ο παραπάνω υπολογισμός και μετά σε πόσο χρόνο αντιστοιχεί (sec).

β)
αλλάξτε το επίπεδο βελτιστοποίησης του compiler: -O0, -O1, -O2, -O3
τι παρατηρείτε ?

γ)
αλλάξετε το define σε 100000
γίνεται compile η εφαρμογή σας? αν ναι, τι μέγεθος έχει?
αν όχι αλλάξτε τις ρυθμίσεις sto linker script ώστε να γίνεται compile

δ)
μπορούμε μέσω software να ενεργοποιήσουμε ή απενεργοποιήσουμε την cache,
πρέπει να γίνει όμως πρώτα #include "cache.h"

(Εξετάστε περιπτώσεις για L1 , L2 cache).

Παράδοση Τετάρτη 8/11/2023

Please upload your Lab in the appropriate folder : "Εργασίες"

George.

Video - μάθημα 19 Οκτωβρίου 2023

Thu, 19 Oct 2023 11:06:10 +0300

Καλημέρα,

https://drive.google.com/file/d/1xxKGvVMDi67bHUA7DJ412yU_O1y5KCVS/view?usp=sharing

https://drive.google.com/file/d/1CG31041Kv7HD4XK_pEHbjKFzXAq7FMBR/view?usp=sharing

Video - μάθημα 12 Οκτωβρίου 2023

Fri, 13 Oct 2023 09:25:41 +0300

https://drive.google.com/file/d/11jYvAIkhOVP3IVz-XrH6dmZKJEIMl4NG/view?usp=sharing

Video - μάθημα 5 Οκτωβρίου 2023

Thu, 05 Oct 2023 12:30:11 +0300

https://drive.google.com/file/d/1RoCW9HFn0yZJ5bXYxyiO6qenI2w8yZsc/view?usp=drive_link

Μάθημα 5-Οκτ-2023

Wed, 04 Oct 2023 20:06:33 +0300

Καλησπέρα σας,

το μάθημα αύριο 5-Οκτ-2023 θα λάβει χώρα στο Εργ1, στις 08:30.

Γιώργος