Tag Archives: phototransistor

Arduino reading screen flashes

I’ve upgraded the hardware to include two LEDs in addition to the phototransistor. Based on the reading of the screen flashes, the LEDs flash according to the key shown. Here’s a video of the system in action: This is at … Continue reading

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Arduino Phototransistor Signal Protocol

I’ve designed a signal protocol for the Arduino to convert phototransistor readings from the laptop screen into bytes of data. Here’s what I came up with today: In the illustration, the white boxes in the black strip are light pulses … Continue reading

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Arduino reads screen flashes with phototransistor

This is the first test of the communication system as described in the previous entry. The flashes are one millisecond, followed by a one second delay. The serial monitor informs me that the microcontroller is able to count them. Here’s … Continue reading

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Computer/Arduino Communication Via Phototransistor

Here’s the basic idea: I’ll send commands to the Arduino by flashing a rectangle on the screen and having a phototransistor on the Arduino read the light level. The above photo shows the test bed set-up. This is very similar … Continue reading

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Arduino Cheapbot gets a Mini Breadboard Makeover

Videos of delivery guys gone wild may be viral these days, but Santa Zero was good to me and delivered these presents intact and on time. They will help in making my cheapbot kit a reality. I’ve only just browsed … Continue reading

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Arduino robot with phototransistor mode switch (attempt #1)

I have a program (aka ‘sketch’) which steers my arduino robot (ie, cheapbot) in a square path. I revised it to use a phototransistor as a mode switch between standby and act (ie, move) modes. Originally, I used the delay() … Continue reading

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Phototransistor as robot mode switch

Here’s the thing about cheapbot: as soon as you program it, it wants to go. It really needs a mode switch with two modes: one to accept commands, and the other to execute them. Also I want to be able … Continue reading

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