list of posts

  1. [thumb] 55. Speech to birdsong conversion

    How human speech could be converted to a birdsong by extracting one of the harmonics.

  2. [thumb] 54. Plotting patterns in music with a fantasy record player

    Sometimes you can see patterns on the surface of vinyl records. What do they mean?

  3. [thumb] 53. Capturing PAL video with an SDR (and a few dead-ends)

    Trying to get live digital video from a 1980s gaming console.

  4. [thumb] 52. Beeps and melodies in two-way radio

    My PMR listening stations classifies and visualizes tones and beeps it hears.

  5. [thumb] 51. Animated line drawings with OpenCV

    Creating simple animations at pixel level with a C++ computer vision library.

  6. [thumb] 50. In pursuit of Otama's tone

    Simulating the sound of the Otamatone for a music project.

  7. [thumb] 49. Descrambling split-band voice inversion with deinvert

    A tool to reverse a primitive kind of voice encryption.

  8. [thumb] 48. Gramophone audio from photograph, revisited

    Examining Tommy the robot's voice box once more.

  9. [thumb] 47. Virtual music box

    Findings and sound samples from a music box synthesizer project.

  10. [thumb] 46. CTCSS fingerprinting: a method for transmitter identification

    Identifying FM walkie-talkies from demodulated baseband audio.

  11. [thumb] 45. Redsea 0.7, a lightweight RDS decoder

    Redsea the RDS decoder got fast enough to be run on a Raspberry Pi 1.

  12. [thumb] 44. Barcode recovery using a priori constraints

    Blurring is not enough to remove a barcode from a picture.

  13. [thumb] 43. Pea whistle steganography

    Would anyone notice if a referee's whistle transmitted a secret data burst?

  14. [thumb] 42. The microphone bioamplifier

    Examining biological signals using a microphone preamplifier.

  15. [thumb] 41. Case study: tinnitus with distortion

    Speculation on the etiology of a specific type of tinnitus.

  16. [thumb] 40. Trackers leaking bank account data

    Under no circumstance is our customers' personal information transmitted to a third party.

  17. [thumb] 39. Receiving RDS with the RTL-SDR

    RTL-SDR support for my RDS decoder, redsea.

  18. [thumb] 38. My chip collection

    Selected specimens from my pile of salvaged ICs.

  19. [thumb] 37. Visualizing hex dumps with Unicode emoji

    All 256 byte values mapped into human-friendly pictograms.

  20. [thumb] 36. Headerless train announcements

    Reverse-engineering a proprietary ADPCM encoding.

  21. [thumb] 35. Time-coding audio files

    Ways to embed UTC time into audio recordings.

  22. [thumb] 34. Mystery signal from a helicopter

    Decoding helicopter telemetry first mistaken as interference.

  23. [thumb] 33. Misleading representations of discrete-time signals

    A weird artifact displayed by some audio tools, and ways around it.

  24. [thumb] 32. Decoding radio-controlled bus stop displays

    Decoding the rest of the DARC layers plus the bus stop application.

  25. [thumb] 31. Broadcast messages on the DARC side

    Physical layer decoding of the DARC protocol.

  26. [thumb] 30. The burger pager

    Examining pager devices used in restaurants.

  27. [thumb] 29. LAN file transfer with netcat

    Silly hack for quick file transfer from the *nix command line.

  28. [thumb] 28. Squelch it out

    Silencing quiet passages of signals to lose entropy and save space.

  29. [thumb] 27. Reader challenge explained

    Explanations to the puzzles, but no actual solutions.

  30. [thumb] 26. The flyback sonar

    Could a CRT flyback transformer be used as a Doppler sonar?

  31. [thumb] 25. Reader challenge: Obfuscated messages

    Little puzzles for my beloved readers.

  32. [thumb] 24. A home-made hand-held Ethernet wiretap

    An Ethernet hub can be used to eavesdrop on passing traffic.

  33. [thumb] 23. Descrambling the voice inversion scrambler

    Simple methods to digitally reverse voice inversion.

  34. [thumb] 22. A determined 'hacker' decrypts RDS-TMC

    Cryptanalysis of the cipher used in RDS-TMC.

  35. [thumb] 21. Tomy Electronic PUCKMAN

    A toy I found at a flea market.

  36. [thumb] 20. How I discovered RDS

    My roundabout journey into FM-RDS and how I initially decoded it using only my radio's Line Out.

  37. [thumb] 19. Portable TV, Raspberry-Pified

    Mini-teardown of a mini-CRT, interfacing it with a Raspberry Pi, and destroying the Pi.

  38. [thumb] 18. Rendering PCM with simulated phosphor persistence

    A method for plotting nice-looking waveforms.

  39. [thumb] 17. Eavesdropping on a wireless keyboard

    Is it safe to use an old Logitech wireless keyboard?

  40. [thumb] 16. RDS display on a Raspberry Pi

    Porting the RDS decoder to the Raspberry Pi and attaching a little LCD.

  41. [thumb] 15. Beyond the hiss

    The various components in cassette tape noise and interference.

  42. [thumb] 14. Voice over laser

    Modulating a laser beam with voice using everyday equipment.

  43. [thumb] 13. The laser-equipped Lego train

    Optical capture of gramophone audio from the Atomic Powered Robot.

  44. [thumb] 12. Case modding, the polish way

    Improving CD jewel cases using nail polish.

  45. [thumb] 11. The atomic powered robot

    Teardown of an old toy and examining its audio device.

  46. [thumb] 10. The GSM buzz

    What does the iconic sound mean?

  47. [thumb] 9. SSTV reception on Linux

    A C program for shortwave listeners.

  48. [thumb] 8. The infrared impulse

    Receiving an IR remote using a sound card.

  49. [thumb] 7. The sound of the dial-up, pictured

    Explaining the various phases of the familiar dialup handshake process.

  50. [thumb] 6. Enchanting subcarriers on FM, part 2

    Modifying my radio by adding a digital RDS output connector.

  51. [thumb] 5. Enchanting subcarriers on FM

    Planning a direct RDS output from the radio's decoder chip, instead of the Line Out hack.

  52. [thumb] 4. Character recognition, the simple way

    A Perl hack for reading 1's and 0's out of a picture.

  53. [thumb] 3. Vintage bits on cassettes

    Save digital data on a compact cassette using an ordinary cassette deck.

  54. [thumb] 2. Summer fun: tinkering with a broken GPS

    Fixing a vintage GPS receiver and interfacing it with Linux.

  55. [thumb] 1. Google Earth on 64-bit Linux

    A tip to get it working.


  1. I coincidentally (seems I participated in the slashdotting of your site) discovered your blog today and I really enjoyed reading it, have bookmarked it and visit again. It is very well written and above all it is about projects that are very interesting to me. I really liked 'beyond the hiss' and the other RF / signals posts. Exploring these kind of things has always been a driver for my interest in electronics and later my career.


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