[Shenzhen IO] precise Food Scale (some understanding of assembly language)

Steam game ： Shenzhen IO

In the near future , Contact Shenzhen IO This game , In the main task of learning the deep learning network, the branch task of assembly language is started , I found it interesting to learn assembly language , But also quite exercise programming thinking .

As a little white who has never learned embedded system or assembly language , At present already “ play ” 了 38h, Here we go Accurate food scale this , Record some understanding .

Ironically , This “Shenzhen IO” The game cannot be played in the national service , You need to register an overseas account .

Precise food is called functional requirement

It is no different from the electronic scales we use everyday , This scale has “ Turn it on ”,“ To turn it off ”,“ Net weight ”（ peel ） These three functions .

Code implementation

The idea of this design and implementation is very simple , The chip on the left is used to judge the current state of the electronic scale , Press down “ Button ” after , It should be turned on （dat Set up 1）, Or turn it off （dat Set up 0）, Or record the tare weight , And clear the current weight （dat Set up 3）.
This design can really meet the requirements , But look at the results , The segment that belongs to the tail of the crane among global players .

The best way to see the product cost is ￥5, There's no doubt about it ：
This electronic scale can use a MC6000 Realized ！

Code optimization ideas

When learning advanced languages , Will often apply Combine several simple logic , Do complex functions The logic of , in other words , Sometimes code , Fine “ Without brains ”, As long as the conditions , Simply and crudely knock it all out .
But that's how it works , In compiling this “ low-level ” Language , It often doesn't work , Mainly because ： The chip limits the number of lines of code , And the ability of assembly language in nested logic , Higher level languages are really hard to use .

At least in Shenzhen IO This game is like this , Involving nested logic , It's really a headache , And high-level languages directly write more layers if That's it

So when using assembly , It has to be “ With brain ”, Before you write a program, think about how the code can be streamlined and smart . And the most important method that I summarize personally is ： Conduct Conditional merger , Find the key conditions .

Code optimization methods

Signal Planning

If only one piece is used MC6000 chip , That can be operated acc Must be used for net weight ,dat Used to record tare （ Input as gross weight ）

Condition sorting

The core focus of this design task & The difficulty lies in how to distinguish “ Turn it on ”,“ To turn it off ”,“ Zeroing （ peel ）” These three functions .

① Startup conditions

• Button =100
• weight （ Gross weight ）=0
• tare =999（ The state before power on must be turned off , The shutdown status is defined as net weight =-999）

② Shutdown conditions

• Button =100
• weight （ Gross weight ）=0
• tare =0

③ Set zero condition

• Button =100
• weight （ Gross weight ）＞0
• tare =0（ The tare weight is still 0, In the next state , The tare weight will be equal to the gross weight at this time ）

Now let's start sorting and merging , First , The three functions can be combined into two , Starting and zeroing are essentially a state （ Boot tare is 0）
Next , As long as from the above conditions , find The simplest sufficient condition to distinguish between shutdown and zero setting states That's it .
That's it ：
① Set zero condition

• weight ≠ tare

② Shutdown conditions

• weight = tare

Find this condition , You can build a new design .

Design optimization

Running results ,world best design！