concept demos
small interactive apps, one idea each. play with them; the concepts are from the lifi project.
input, processing & output
the ipo test lab
change sensor values and the classification rule, compare actual with expected output, and watch the test pass or fail.
measurement and experiments
the noisy sensor
send a symbol over a noisy link and let the same readings decide it three times: alone, averaged over five, averaged over ten. fewer wrong decisions, less speed.
symbols & information
question game
find the secret face among sixteen: every answer shrinks the crowd, the shrinking is measured in bits, and the halving strategy shows why four questions are enough.
analog & digital
the copier
press copy and hang each generation on the wall: watch the analog picture fade copy by copy, then ask what a file would have done.
the photo digitiser
turn an analog photo into numbers: pick resolution and colour depth (down to the game boy's four greys), see the picture change, and watch the byte count grow.
the audio digitiser
the same two cuts for sound: choose sampling rate and bit depth, see the staircase on the wave — and hear what gets thrown away.
signal & noise
distinguishability lab
send symbols over a noisy channel, oscilloscope style: grow the alphabet, tune the window, inject a disturbance, and watch the error rate fight the throughput.
sampling & synchronization
drift simulator
two clocks, slightly apart: watch the receiver’s sampling points wander out of the time slots until the message turns to garbage, then let a sync marker save it.
throughput & limits
where did the bits go?
send a photo over a framed link: watch every symbol cross while headers, checks and retries consume time without growing the picture.
number systems
byte switchboard
flip eight bits and watch the number appear: binary, decimal, hex, and the ascii character behind it.
code systems
the prefix trap
write your own code words, send a word, and see every reading the receiver could pick. get the list down to one and you have built a code that works.
pixel painter
an 8×8 picture, one bit per pixel: paint and watch the bytes write themselves, edit the hex and paint with numbers, then break a byte and see the damage.
files
inside a file
a real bitmap in a hex editor: header fields underlined, click a pixel to find its three bytes, then change a byte — and watch the picture obey, or the viewer refuse.
logic & arithmetic
the pixel filter
make a photo brighter one addition at a time: step through a single pixel with its bits and carries, then let the machine do the other sixteen thousand in a blink.
the gate lab
switches in, lamps out: flip the inputs of a single gate, watch a half adder carry, chain eight full adders into a byte adder, and make two gates remember a bit.
more concepts
more demos will appear here as the course grows.