Writing about raspberry-pi


So far we've built the Etch-A-Snap and processed an image to produce a 1 bit image. In this part we’ll look at how to take this image and generate the draw instructions for the plotter.

Etch-A-Sketch is a very simple 2D plotter which is limited to drawing a single …

The image processing produces a 1 bit image (B&W) of 240x144 pixels. The next step is to take this image and convert it into movements for the motors.

An example processed 1 bit image

The way this is done is governed largely by the design of the Etch-A-Sketch — any drawing must be made in one …

Etch-A-Sketch is a very simple 2D plotter which is limited to drawing a single unbroken line, of a single thickness and colour which is dark-ish on a silver-ish screen. To be able to plot a photo onto the Etch-A-Sketch we need to transform the image so that —

  1. the resolution makes …
Pocket Etch-A-Sketch Not the really really tiny one. amazon
3D PrinterI have & recommend the Anycubic i3 Mega. amazon
PLARed, white & black amazon
2x 5V 28BYJ-485V stepper motor. amazon
2x ULN2003A IC Darlington array, as stepper driver chip. amazon
1x 330Ω resistor for LED driven off Pi …

Etch-A-Snap is (probably) the worlds first Etch-A-Sketch Camera. Powered by a Raspberry Pi Zero (or Zero W) it snaps photos just like any other camera, but outputs them by drawing to an Pocket Etch-A-Sketch screen. Quite slowly.

Photos are processed down to 240x144 pixel 1-bit (black & white) line drawings using …


Pulse sensors are a common feature of fitness monitors, used to track your activity and cardiac fitness over time. These external monitors use the reflection and absorption of bright green/infra-red light to detect the pulse wave travelling down the artery — a technique called photoplethysmography (PPG). This same techique is …


KropBot is a little multiplayer robot you can control over the internet. Co-operate with random internet strangers to drive around in circles and into walls.

If it is online, you can drive the KropBot yourself!

Raspberry Pi Zero W amazon
Pi Zero Camera amazon
Pi Zero Camera Cable Watch …

The Scroll pHAT is a little 11x5 (55) white LED matrix pHAT which you can control easily from a Raspberry Pi. In this project we'll squeeze a tiny-yet-playable game of Tetris onto the Scroll pHAT.

Raspberry Pi Zero / Zero W You don't need wireless for this project, but it …
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