Prototype wiring preparations

A project log for TextEye: Raspberry Pi (Zero) Mobile Textreader

A mobile text scanner/reader for people with severe visual impairments

Markus DieterleMarkus Dieterle 03/28/2016 at 16:370 Comments

Time for another project update...

Breadboard prototype

I did not do much coding over the Easter weekend, but instead took some time to get more familiar with Fritzing and think about how to wire up the different components. A few things are still missing, but here is the wiring for the breadboard prototype that I came up with so far:

For the Raspberry Pi Zero, the prototype setup looks the same, just with the Pi Zero instead of the Model B(+)/2:

The only thing still missing from the Fritzing sketches is essentially the USB webcam. I'm thinking about creating a custom part for Fritzing in order to complete the sketch in this direction.

The NeoPixel strip in the upper right corner is just for additional lighting when taking a picture. It can be omitted or replaced by a bright white LED or even an external light source.

The T-Cobbler is just used for a cleaner and easier connection between the GPIO pins on the Raspberry Pi and the rest of the parts. It can be considered to be part or the overall wiring.

At the moment, the rest of the parts are as follows:

This setup should provide enough power for a mobile usage of the Raspberry Pi while also providing audio output for the Pi Zero.

Wiring up the parts

Here are the details for the part connections of the different parts mentioned above:

Raspberry Pi GPIO:

MCP4725 12-bit DAC board:

PAM8302A 2.5W mono amplifier board:

NeoPixel Stick/Strip:

1N4001 Diode:

Powerboost 1000C charger board:

Optional/Temporary slide switch:

The next thing to do - apart from finishing the software - will be to solder some additional pins and connections so that everything can be tested. The audio output via the DAC board and amplifier board will also need some additional configuration and testing.

That's all for now.