October (Issue #435) Circuit Cellar

Click here for the Circuit Cellar article code archive

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This issue is available in PDF format from our webshop.
As individual articles are made available on the website they will be linked on the TOC page-here

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4: CodeBuddy Timmy – A Mini Educational Robot for Interactive Learning, By Madelin Prak and Junwoo Kwon

RESOURCES

REFERENCES
[1] Adam Dunkels. “Protothreads.”  https://dunkels.com/adam/pt/
[2] Demonstration video of CodeBuddy Timmy in action.  https://www.youtube.com/watch?v=teVmPDNyPdc

Article Materials & Code Files

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4: Automated Test Equipment for 7400-Series Integrated Circuits – Use an RP2040 MCU to Find Manufacturing Flaws in Chips, By Michelle Yang

RESOURCES
Microchip | www.microchip.com
Raspberry Pi | www.raspberrypi.com

SOURCES
Test ICs (7400 NAND, 7402 NOR, 7404 NOT, 7408 AND, 7432 OR, 7474 D FLIP-FLOP) from Texas Instruments, purchased on DigiKey.
https://www.digikey.com/en/products/filter/logic/gates-and-inverters/705

MCP23s17 port expander from Microchip.
https://www.microchip.com/en-us/product/mcp23s17

Raspberry Pi Pico RP2040 from Raspberry Pi:
https://www.raspberrypi.com/products/raspberry-pi-pico/

VGA adapter from Hunter Adams (Cornell University):
https://vanhunteradams.com/Pico/VGA/VGA.html

REFERENCES
[1] Adam Dunkels, “Protothreads.” https://dunkels.com/adam/pt/

[2] Bruce Land, MCP23s17 port expander documentation: https://people.ece.cornell.edu/land/courses/ece4760/PIC32/index_port_expander.html

[3] V. Hunter Adams’ VGA graphics documentation for the RP2040
https://vanhunteradams.com/Pico/VGA/VGA.html

[4] Pending

[5] TTSMP3, a free text-to-speech converter. https://ttsmp3.com/

[6] FreeConvert:  https://www.freeconvert.com/

[7] FileToCArray: https://notisrac.github.io/FileToCArray/

Article Materials & Code Files

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10: Optimizing Wireless Communications – Make the Right Choices for Best Performance, By Pedro Bertoleti

RESOURCES
LoRa | lora-alliance.org
LoRaWAN | lora-alliance.org/about-lorawan

REFERENCES
[1] https://www.researchgate.net/figure/LoRa-uses-a-chirp-spread-spectrum-modulation-technique-The-figure-also-shows-that-LoRa_fig3_332151302)
[2] “Wireless Communications: Principles and Practice”: T. S. Rappaport, Wireless Communications: Principles and Practice, 2nd ed. Upper Saddle River, NJ, USA: Prentice Hall, 2002.
[3] “Computer Networking: A Top-Down Approach”: “Computer Networking: A Top-Down Approach”: J. F. Kurose and K. W. Ross, Computer Networking: A Top-Down Approach, 8th ed. Chennai, India: Pearson India Education Services, 2022.

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18: Building a Small, Autonomous Car – Two Raspberry Pi Picos Carry the Load, By Gebran Kastoun, Ruby Wu, and Sarah Zhong

RESOURCES
Bosch Sensortec | bosch-sensortec.com
Raspberry Pi Foundation | raspberrypi.com

REFERENCES
[1] https://github.com/JRDPropulsion/BNO055-RP2040-Library/blob/main/src/BNO055.cpp

[2] Autonomous drawing vehicle with Raspberry Pi Pico

Data Sheets

Bosch BNO055 9-DOF Absolute Orientation Sensor Datasheet

Raspberry Pi Pico W Datasheet

RP2040 Microcontroller Datasheet

Vendor Sites

Raspberry Pi Foundation: https://www.raspberrypi.com/

Bosch Sensortec: https://www.bosch-sensortec.com/

Code/Designs Borrowed from Others

JRDPropulsion BNO055-RP2040-Library: https://github.com/JRDPropulsion/BNO055-RP2040-Library/blob/main/src/BNO055.cpp (C++ library adapted to C)

UDP Networking: Andrew McDonnell (2022), Stephan Linz (2016), Raspberry Pi Pico examples (https://github.com/raspberrypi/pico-examples/tree/master/pico_w/wifi/udp_beacon)

Protothreads: Original by Adam Dunkels (Swedish Institute of Computer Science, 2004-2005), Cornell RP2040 version by Bruce Land (BRL4), Cornell University

VGA Graphics: Original by Hunter Adams (vha3@cornell.edu), 16-color modifications by Bruce Land (BRL4)

TinyUSB: Ha Thach (tinyusb.org), https://github.com/hathach/tinyusb

lwIP: https://savannah.nongnu.org/projects/lwip/

Raspberry Pi Pico SDK: https://github.com/raspberrypi/pico-sdk

Professors Bruce Land and Van Hunter Adams’ ECE 4760 Examples: USB Host HID (Professor Land), UDP communication (Professor Land), VGA graphics framework (Professors Land and Hunter Adams), protothreads (Professor Land), PWM motor control (Professor Hunter Adams), I2C communication (Professor Hunter Adams), sensor interfacing (Professor Hunter Adams)

Background Sites/Papers

Raspberry Pi Pico C/C++ SDK Documentation: https://datasheets.raspberrypi.com/pico/raspberry-pi-pico-c-sdk.pdf

lwIP Documentation: https://www.nongnu.org/lwip/2_1_x/index.html

TinyUSB Documentation: https://docs.tinyusb.org/

Protothreads Documentation: https://dunkels.com/adam/pt/

Cornell ECE 4760 Course Materials: https://people.ece.cornell.edu/land/courses/ece4760/

Citations

JRDPropulsion. (n.d.). BNO055-RP2040-Library [Computer software]. GitHub. BNO055-RP2040-Library

Land, B. (n.d.-a). RP2040 Protothreads. Cornell University, ECE 4760. Cornell RP2040 Protothreads

Land, B. (n.d.-b). UDP data array from PicoW to PicoW. Cornell University, ECE 4760. Cornell Pico W UDP example

Land, B., & Adams, V. H. (n.d.). Protothreads with 640 × 480 VGA 16-color. Cornell University, ECE 4760. Cornell VGA/Protothreads example

Article Materials & Code Files

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34: TECHNOLOGY FEATURE: Control and Protect Critical Infrastructure – The Two Sides of OT Management and Cybersecurity, By Curtis Franklin

RESOURCES

ABB | new.abb.com

Cisco | cisco.com

Claroty | claroty.com

CrowdStrike | crowdstrike.com

Dragos | dragos.com

Emerson | emerson.com

Fortinet | fortinet.com

Honeywell | process.honeywell.com

IBM | ibm.com

Microsoft | microsoft.com

Nozomi Networks | nozomi.com

Palo Alto Networks | paloaltonetworks.com

Rockwell Automation | rockwellautomation.com

Schneider Electric | se.com

Siemens | siemens.com

Splunk | splunk.com

Tenable | tenable.com

TXOne Networks | www.txone.com

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40: DATASHEET: System Testing Components – Put Systems Through Their Paces – Frameworks and Instruments for Ensuring Things Are Right, By Curtis Franklin

Datasheet URLs:

CppUTest: https://cpputest.github.io/manual.html

Fluke: https://www.fluke-direct.com/pdfs/cache/www.fluke-direct.com/87v-max/datasheet/87v-max-datasheet.pdf

RIGOL Technologies: https://www.rigolna.com/products/dc-power-loads/dp800/l

Salea: https://downloads.saleae.com/specs/logic_pro_16_data_sheet.pdf

SEGGER Microcontroller Systems: https://www.segger.com/products/debug-probes/j-link/models/j-link-plus/

Siglent Technologies: https://shop-us.siglent.com/wp-content/uploads/2025/11/SDS2000X-HD_Datasheet_EN02A.pdf

STMicroelectronics: https://www.st.com/en/development-tools/stlink-v3set.html

Tekctronix: https://www.tek.com/en/datasheet/4-series-b-mso-mixed-signal-oscilloscope-datasheet

Throw the Switch: https://www.throwtheswitch.org/ceedling

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44: START TO FINISH: Standing Wave Ratio – Understanding Antenna Efficiency, By Stuart Ball

RESOURCES

DigiKey | www.digikey.com

NanoVNA | nanovna.com

TE Connectivity | te.com

References:

[1] Wikipedia article on Abraham-Lorentz force: https://en.wikipedia.org/wiki/Abraham%E2%80%93Lorentz_force

[2] Wikipedia article on radiation resistance: https://en.wikipedia.org/wiki/Radiation_resistance

[3] Wikipedia article on Maxwell’s equations: https://en.wikipedia.org/wiki/Maxwell%27s_equations

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49: MODERN EMBEDDED INSIGHTS: Zephyr RTOS – Leveraging an Ecosystem of Drivers and Middleware, By Jacob Beningo

RESOURCES

NXP | www.nxp.com

Zephyr Project | www.zephyrproject.org

Additional Resources

Free Webinar – Getting Started with the MCUXpresso SDK for NXP MCUs

Free Webinar – Migrating from FreeRTOS to Zephyr RTOS

Free Webinar – Mastering Zephyr Devicetree

[1] https://www.beningo.com/mastering-the-zephyr-rtos-devicetree-and-overlays/

[2] FRDM-MCXN947 https://www.nxp.com/part/FRDM-MCXN947

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54: UNCHARTED HARDWARE: A Steampunk GPS Desk Clock –    Building with a Tiny LCD Screen and GPS, By Rob “Dr. Torq” Reilly

RESOURCES

Adafruit | www.adafruit.com

FreeCAD | www.freecad.org

Fritzing | fritzing.org

Sparkfun | www.sparkfun.com

Adafruit 2.0″ 320×240 Color IPS TFT Display with microSD Card breakout board. https://www.adafruit.com/product/4311

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63: TECH THE FUTURE: The Future of Temperature Monitoring –    Refrigerator Failure Prevention -Temperature Monitoring Must Move Beyond the Clipboard, By Chris Potts

RESOURCE

ANT Telecom
www.anttelecom.co.uk