Article was first published on wechat official account @codename XY author: codename XY

Hello, I’m XY.

“Everyday Tips” is a list of tips I discovered while working on a project with RZ,

It can be applied in everyday life.

In the future we will accumulate the relevant procedures to write open source.

① First, you need a camera

The average price of a certain treasure ranges from 20 yuan to 200 yuan to 400 yuan. Just like choosing a camera, pixel and frame rate are hard indicators.

It’s something you can reuse and easily disassemble.

② You also need a microphone, a pair of speakers, or a speaker,

USB, cable, or traditional audio ports are optional.

③ But it is a pity that

To make 🐈 call, there is no inevitable ta, only “chance”. Of course, you can try to train them.

We need a sensor to get its jio or body to start talking.

Like a button

Or touch sensors,

Or photosensitive resistance.

Pressure film sensor:

Pressure signal

When the sensor senses the external pressure, the resistance value of the sensor will change. The simple circuit can make the sensor change the pressure signal into the electrical signal output of the corresponding change intensity after sensing the pressure change

Touch switch sensor:

Generates a signal that indicates whether it is touched by a finger, and switches the circuit according to this signal.

Photosensitive resistor:

Light as signal

A special resistance that utilizes the effect of photoconductivity and whose resistance is directly related to the intensity of the incident light. When the light intensity increases, the resistance decreases. As the light intensity decreases, the resistance increases.

④ Most importantly, you’ll need a development board, and raspberry Pie is recommended.

It runs Linux and is itself a small computer on which Android is based.

Equipped with wifi module, you can access wireless network.

⑤ Of course, you will also need some wires

You need to plan their length

And a shield to cover the protective raspberry PI and the camera.

You can buy a shell like this,

Or you can do it yourself.

To get the hardware to work,

I need to program the Raspberry PI,

Fortunately, there are many open source software packages available online

(This code is so tired that I can’t read it. Let’s skip this.)

⑤ Then, you need to find a live video calling service

This type of PaaS service can be invoked directly in raspberry Pie

So you can make video calls with raspberry PI.

Usually this service is within a certain range

For example, 10,000 minutes is free.

⑥ Let’s connect those modular devices to the Raspberry PI

You need to position each module properly,

The length of the connections between the various hardware modules,

Don’t let the cat break the camera or the raspberry pie,

It’s important to think about where to put the sensor for its Jio touch.

Come to think of it

Preferably somewhere cats spend a lot of time

For example, he or she often looks over a distant window

Like where they eat, in front of the cat bowl

Or anywhere

Is it going to step on that button or sensor

See fate (???)

We didn’t do anything like that

But we did test the video call part

Agora for Video calling Services (non-advertising)

A success

The window on the right is raspberry pie

So you can make your own hardware video

You can also apply this “combination” to more ideas.

RZ says one of the most interesting findings of the camera, microphone and speaker tests was “latency.”

Although this is common sense, it is only strongly felt when tested. When the voice or video becomes a digital signal to the person we are talking to, there is always a delay. Even for a few milliseconds.

Unless we can travel faster than light.

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