Silicon ChipNon-contact cloud-based temperature sensor with speech - December 2021 SILICON CHIP
  1. Outer Front Cover
  2. Contents
  3. Publisher's Letter: Making kits is not easy!
  4. Mailbag
  5. Feature: Big Brother is Tracking You! – Part 2 by Dr David Maddison
  6. Project: Hummingbird Audio Amplifier by Phil Prosser
  7. Feature: SMD Soldering – tips and tricks by Tim Blythman
  8. Project: SMD Trainer Board by Tim Blythman
  9. Feature: El Cheapo Modules: 35MHz-4.4GHz Signal Generator by Jim Rowe
  10. Review: Raspberry Pi Pico by Tim Blythman
  11. Project: Digital Lighting Controller Translator by Tim Blythman
  12. Serviceman's Log: A mixed bag of odds, sods, ends and bobs by Dave Thompson
  13. Product Showcase
  14. Circuit Notebook: Orrery (planetarium) using a Micromite LCD BackPack by Kenneth Horton
  15. Circuit Notebook: Non-contact cloud-based temperature sensor with speech by Bera Somnath
  16. Circuit Notebook: Switching cells between parallel and series by Benabadji Mohammed Salim
  17. Circuit Notebook: Connecting two pushbuttons to an input-only pin by Amine Houari
  18. Project: USB Cable Tester – Part 2 by Tim Blythman
  19. Vintage Radio: Restoring a Sony 5-303E Micro-TV by Dr Hugo Holden
  20. Subscriptions
  21. PartShop
  22. Ask Silicon Chip
  23. Market Centre
  24. Advertising Index
  25. Notes & Errata: Tele-com Intercom, October 2021; Hybrid Lab Supply with WiFi, May & June 2021
  26. Outer Back Cover

This is only a preview of the December 2021 issue of Silicon Chip.

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Articles in this series:
  • Big Brother is Tracking You! – Part 1 (November 2021)
  • Big Brother is Tracking You! – Part 2 (December 2021)
Items relevant to "Hummingbird Audio Amplifier":
  • 6-way Loudspeaker Protector PCB [01101221] (AUD $7.50)
  • 4-way Loudspeaker Protector PCB [01101222] (AUD $5.00)
  • The Hummingbird Audio Amplifier PCB [01111211] (AUD $5.00)
  • Hard-to-get parts for the Hummingbird Amplifier (Component, AUD $15.00)
  • Multi-Channel Speaker Protector PCB patterns (PDF download) [01101221-2] (Free)
  • The Hummingbird Audio Amplifier PCB pattern (PDF download) [01111211] (Free)
Items relevant to "SMD Trainer Board":
  • SMD Trainer PCB [29106211] (AUD $5.00)
  • Kit for the SMD trainer (Component, AUD $20.00)
  • SMD Trainer PCB pattern (PDF download) [29106211] (Free)
Articles in this series:
  • El Cheapo Modules From Asia - Part 1 (October 2016)
  • El Cheapo Modules From Asia - Part 2 (December 2016)
  • El Cheapo Modules From Asia - Part 3 (January 2017)
  • El Cheapo Modules from Asia - Part 4 (February 2017)
  • El Cheapo Modules, Part 5: LCD module with I²C (March 2017)
  • El Cheapo Modules, Part 6: Direct Digital Synthesiser (April 2017)
  • El Cheapo Modules, Part 7: LED Matrix displays (June 2017)
  • El Cheapo Modules: Li-ion & LiPo Chargers (August 2017)
  • El Cheapo modules Part 9: AD9850 DDS module (September 2017)
  • El Cheapo Modules Part 10: GPS receivers (October 2017)
  • El Cheapo Modules 11: Pressure/Temperature Sensors (December 2017)
  • El Cheapo Modules 12: 2.4GHz Wireless Data Modules (January 2018)
  • El Cheapo Modules 13: sensing motion and moisture (February 2018)
  • El Cheapo Modules 14: Logarithmic RF Detector (March 2018)
  • El Cheapo Modules 16: 35-4400MHz frequency generator (May 2018)
  • El Cheapo Modules 17: 4GHz digital attenuator (June 2018)
  • El Cheapo: 500MHz frequency counter and preamp (July 2018)
  • El Cheapo modules Part 19 – Arduino NFC Shield (September 2018)
  • El cheapo modules, part 20: two tiny compass modules (November 2018)
  • El cheapo modules, part 21: stamp-sized audio player (December 2018)
  • El Cheapo Modules 22: Stepper Motor Drivers (February 2019)
  • El Cheapo Modules 23: Galvanic Skin Response (March 2019)
  • El Cheapo Modules: Class D amplifier modules (May 2019)
  • El Cheapo Modules: Long Range (LoRa) Transceivers (June 2019)
  • El Cheapo Modules: AD584 Precision Voltage References (July 2019)
  • Three I-O Expanders to give you more control! (November 2019)
  • El Cheapo modules: “Intelligent” 8x8 RGB LED Matrix (January 2020)
  • El Cheapo modules: 8-channel USB Logic Analyser (February 2020)
  • New w-i-d-e-b-a-n-d RTL-SDR modules (May 2020)
  • New w-i-d-e-b-a-n-d RTL-SDR modules, Part 2 (June 2020)
  • El Cheapo Modules: Mini Digital Volt/Amp Panel Meters (December 2020)
  • El Cheapo Modules: Mini Digital AC Panel Meters (January 2021)
  • El Cheapo Modules: LCR-T4 Digital Multi-Tester (February 2021)
  • El Cheapo Modules: USB-PD chargers (July 2021)
  • El Cheapo Modules: USB-PD Triggers (August 2021)
  • El Cheapo Modules: 3.8GHz Digital Attenuator (October 2021)
  • El Cheapo Modules: 6GHz Digital Attenuator (November 2021)
  • El Cheapo Modules: 35MHz-4.4GHz Signal Generator (December 2021)
  • El Cheapo Modules: LTDZ Spectrum Analyser (January 2022)
  • Low-noise HF-UHF Amplifiers (February 2022)
  • A Gesture Recognition Module (March 2022)
  • Air Quality Sensors (May 2022)
Items relevant to "Digital Lighting Controller Translator":
  • Flexible Digital Lighting Controller main PCB [16110202] (AUD $20.00)
  • Flexible Digital Lighting Controller Micromite Master PCB [16110201] (AUD $5.00)
  • Flexible Digital Lighting Controller CP2102 Adaptor PCB [16110204] (AUD $2.50)
  • Flexible Digital Lighting Controller LED slave PCB [16110205] (AUD $5.00)
  • PIC16F1705-I/P programmed for the Flexible Digital Lighting Controller [1611020A.HEX] (Programmed Microcontroller, AUD $10.00)
  • PIC32MX170F256B-50I/SP programmed for the Flexible Digital Lighting Controller Micromite master [1611020B.hex] (Programmed Microcontroller, AUD $15.00)
  • PIC16F1455-I/P programmed for the Flexible Digital Lighting Controller WS2812 Slave [16110205.HEX] (Programmed Microcontroller, AUD $10.00)
  • Micromite LCD BackPack V3 complete kit (Component, AUD $75.00)
  • Flexible Digital Lighting Controller front panel PCB [16110203] (AUD $20.00)
  • Firmware and software for the Fiexible Digital Lighting Controller (Free)
  • Firmware and PC software for the Digital Lighting Controller [1611010A.HEX] (Free)
  • Flexible Digital Lighting Controller mains slave PCB patterns (PDF download) [16110202-3] (Free)
  • Flexible Digital Lighting Controller Master PCB patterns (PDF download) [16110201, 16110204] (Free)
  • Flexible Digital Lighting Controller LED slave PCB pattern (PDF download) [16110205] (Free)
  • Drilling and cutting diagrams for the Flexible Digital Lighting Controller Micromite master (PDF download) (Panel Artwork, Free)
  • Cutting diagram for the Flexible Digital Lighting Controller mains slave rear panel (PDF download) (Panel Artwork, Free)
  • Cutting diagrams and front panel artwork for the Flexible Digital Lighting Controller LED slave (PDF download) (Free)
  • Digital Lighting Controller Translator PCB [16110206] (AUD $5.00)
  • PIC16F1705-I/P programmed for the Digital Lighting Controller Translator [1611020F.HEX] (Programmed Microcontroller, AUD $10.00)
  • Firmware for the Digital Lighting Controller Translator [1611020F.HEX] (Software, Free)
  • Digital Lighting Controller Translator PCB pattern (PDF download) [16110206] (Free)
  • Drilling/cutting diagrams and lid panel artwork for the Digital Lighting Controller Translator (Free)
Articles in this series:
  • Flexible Digital Lighting Controller, part 1 (October 2020)
  • Flexible Digital Lighting Controller, part 2 (November 2020)
  • Flexible Digital Lighting Controller, part 3 (December 2020)
  • Digital Lighting Controller Translator (December 2021)
Items relevant to "Orrery (planetarium) using a Micromite LCD BackPack":
  • Firmware for the Orrery using a Micromite LCD BackPack (Software, Free)
Items relevant to "Non-contact cloud-based temperature sensor with speech":
  • Firmware for the Contactless temperature sensor with speech (Software, Free)
Items relevant to "USB Cable Tester – Part 2":
  • USB Cable Tester main PCB [04108211] (AUD $7.50)
  • PIC16F18877-I/P programmed for the USB Cable Tester [0410821C.HEX] (Programmed Microcontroller, AUD $15.00)
  • Relay - EA2-5NU (Component, AUD $3.00)
  • IPP80P03P4L-07 high-current P-channel Mosfet (Component, AUD $2.50)
  • Short form kit for the USB Cable Tester (Component, AUD $110.00)
  • USB Cable Tester front panel PCB [04108212] (AUD $5.00)
  • Laser-cut acrylic bezel for USB Cable Tester (PCB, AUD $2.50)
  • Firmware and bezel laser cutting files for the USB Cable Tester [0410821A.HEX] (Software, Free)
  • USB Cable Tester PCB patterns (PDF download) [04108211/2] (Free)
Articles in this series:
  • USB Cable Tester – Part 1 (November 2021)
  • USB Cable Tester – Part 2 (December 2021)

Purchase a printed copy of this issue for $11.50.

Non-contact cloud-based temperature sensor with speech To help track the health of the employees in our department, I have created this non-contact temperature sensor at the entry point. All you need to do is place your forehead close to it (within 2-5cm), and it measures your body temperature and plays back audio to indicate whether it is normal or high. It also uploads the data to a cloud server (www.thingspeak.com) for later analysis. It uses an HC-SR04 ultrasonic sensor to measure the distance to the person. Once that distance is close enough, it measures the temperature, plays back an audio file depending on the reading, then uploads the data to the internet. If it detects that someone is nearby, but not close enough (between 5cm and 78 Silicon Chip 15cm), it plays back an audio file asking them to approach closer. The ESP32 has two digital-to-analog (DAC) outputs at pins 9 & 10 (IO25/26). Audio playback in this case is from pin 9. One of two 8kHz PCM (pulse-code modulated) audio files is played back depending on whether the temperature measurement is below or above 37°C. A special Arduino library is used for this capability (XT_DAC_Audio from xtronical.com). A small 5V audio amplifier using the PAM8403 IC is used to deliver this sound to a 3W 8W loudspeaker. The ESP32’s WiFi capability is used to upload the temperature data to the cloud server at www.thingspeak.com The Arduino sketch to load onto Australia’s electronics magazine the ESP32 is available for download from siliconchip.com.au/Shop/6/6052 You will need to open a free account at www.thingspeak.com and modify the API key in the software to match the one you are supplied with before it will upload data. It supports multiple WiFi networks with separate SSIDs and passwords, so that whichever one is found will be used to transfer data to the cloud. You will need to modify the SSID and Password section of the sketch to contain your network details. The circuit uses two ESP32 modules; one is dedicated to handling the audio playback while the other monitors the temperature and distance sensors and drives the display. siliconchip.com.au The voice-handling module is programmed to play back one of the two sound files when pin 28 or 29 is brought high, and these pins have pulldown resistors to prevent audio playback at power-up or when the other micro is reset. The main ESP32 connects to the ILI9163 colour TFT display via an SPI serial bus, the HC-SR04 ultrasonic ranger via a two-pin digital interface and the MLX90614 IR temperature sensor via an I2C serial bus. As well as playing back the appropriate sound file, the unit also lights the red or green LED (red = high temperature, green = normal temperature), and it sounds the connected piezo buzzer if the temperature is high. Both the ESP32s may be powered from one 5V DC power supply. The audio data I have created is in the files “fever.h” and “ok.h”, while the file that is played when someone is not close enough for measurement is in “wel.h” (short for “welcome”). To change this, first record your desired audio to 8kHz, 16-bit WAV files. You then need to change these files to HEX format. There are many online sound converter sites such as www. fromtexttospeech.com that can do this. You then need to convert the HEX data to C code by using the software HxD from www.mh-nexus.de which produces a simple text file that you can use to replace “fever.h”, “ok.h” or “wel.h”. You can see the data recorded on my cloud server at www.thingspeak. com/channels/1371171 Besides showing the temperature readout on the screen, it also shows a letter code in the lower-left corner. C = Connected to WiFi, U = Data Uploaded, D = Distance measurement. Any form of ESP32, ESP32S or ESP32 S2 module will work for this project. Bera Somnath, Vindhyanagar, India. ($100) Editor’s note: while normal body temperature is generally considered to be 36.5-37°C, it is possible to measure above 37°C without being ill. Some people are simply hotter than others, and exertion and other factors can affect your core temperature to a certain extent. That time of year is nearly here... CHRISTMAS Spice up your festive season with eight LED decorations! Tiny LED Xmas Tree 54 x 41mm PCB SC5181 – $2.50 Tiny LED Cap 55 x 57mm PCB SC5687 – $3.00 Tiny LED Stocking 41 x 83mm PCB SC5688 – $3.00 Tiny LED Reindeer 91 x 98mm PCB SC5689 – $3.00 Tiny LED Bauble 52.5 x 45.5mm SC5690 – $3.00 Tiny LED Sleigh 80 x 92mm PCB SC5691 – $3.00 Tiny LED Star 57 x 54mm PCB SC5692 – $3.00 Tiny LED Cane 84 x 60mm PCB SC5693 – $3.00 We also sell a kit containing all required components for just $14 per board ➟ SC5579 siliconchip.com.au Australia’s electronics magazine December 2021  79