pxt-calliope/docs/lessons/seismograph/challenge.md

# Seismograph Challenge 

Coding challenges for the seismograph. 


### ~avatar avatar

Engineering: In this project, you will build a remote control based on the seismograph micro:bit activity using a second micro:bit and micro USB cable. 

### ~

## What you'll need: 

* BBC micro:bits (2)
* micro USB cables (2) 
* Plate 
* Tape 
* Scissors

![](/static/mb/lessons/seis_challenge01.png)

## Before we get started

Complete the [seismograph](/lessons/seismograph/activity) activity and your code will look like this:

```blocks
basic.forever(() => {
    led.plotBarGraph(input.acceleration(Dimension.Strength) - 1023, 0);
});

```

### ~avatar avatar 
Computer Science: Welcome! The activity will teach you how to code the acceleration of the 1st micro:bit and to visualize the acceleration on the 2nd micro:bit. Let's get started!
### ~

# Computer Science Steps

## 1.
We want to simply detach the blocks from the recent activity. We will use blocks from the activity to create a brand new program to show the way micro:bit devices communicate through the BLE (Bluetooth low energy) radio. 

```shuffle
basic.forever(() => {
    led.plotBarGraph(input.acceleration(Dimension.Strength) - 1023, 0);
});

```

## 2. 
Let's measure `acceleration (mg)` and then `send number`. `Acceleration` is measured in **milli-gravities**, so a value of -1000 is equivalent to -1g or -9.81m/s^2. We will be able to get the acceleration value (g-force), in the specified "x" dimension. `Send number` will broadcast a number data packet to other micro:bits connected via radio.

We need add send number block found in the Radio drawer. We will attach send number to acceleration and subtract the gravity from acceleration strength.  

Your finished code will look like this:

```blocks
radio.sendNumber(input.acceleration(Dimension.Strength) - 1023);
```

## 3. 
We want to display the acceleration forever. In order to do so, we need a `forever` loop. A forever loop will repeat code in the background forever. We need attach forever loop to send number. 

Your finished code will look like this:

```blocks
basic.forever(() => {
    radio.sendNumber(input.acceleration(Dimension.Strength) - 1023);
});

```

## 4. 
We want to register code to run when a packet is received over radio. We can implement this code by adding `on data received`block found in the radio drawer.

Your finished code will look like this:

```blocks
basic.forever(() => {
    radio.sendNumber(input.acceleration(Dimension.Strength) - 1023);
});
radio.onDataReceived(() => {
});

```

## 5. 
Finally, we want to chart the acceleration. So we must first implement `plot bar graph`. `Plot Bar Graph` will display a vertical bar graph based on the value and high value. In order to transfer the receive the number from the 1st micro:bit, we must implement `receive number` to constantly display a vertical bar graph based on the value. Remember, the value will equal to the micro:bit's acceleration in the "x" direction.

Your finished code will look like this:

```blocks
basic.forever(() => {
    radio.sendNumber(input.acceleration(Dimension.Strength) - 1023);
});
radio.onDataReceived(() => {
    led.plotBarGraph(radio.receiveNumber(), 0);
});
```

### ~avatar avatar 
Science: Welcome! The activity will teach you how to chart the acceleration of the 1st micro:bit and to visualize the acceleration on the 2nd micro:bit. Let's get started!
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# Science Steps

## 6. 
First, notice that moving the 1st micro:bit in the simulator in any direction, you will change the acceleration value of the 2nd micro:bit. Also, notice that by moving the micro:bit simulator, there is a changing acceleration value of the second micro:bit. Second, the flat colored horizontal line will start a waving line on the 2nd micro:bit to display the value of the strength as measured in milli-gravities. Finally, notice that the LED display will fluctate based on the movement of the 2nd micro:bit simulator.


![](/static/mb//lessons/seis_challenge02.png)

## 8. 
 
Connect the 2nd micro:bit to your computer using your USB cable. We should have two micro:bit devices attached to the computer. 

![](/static/mb/lessons/seismograph33.png)

Click or tap the compile button for the seismograph program to run the program on the micro:bit. 

![](/static/mb/acc2.png)

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Finally, you must open the Excel CSV file by clicking on the data.xls file that was downloaded to Downloads Folder. 

![](/static/mb/data3.png)

Use the Recommended Charts command on the Insert tab to quickly create a chart that’s just right for your data.

* Select the data that you want to include in your chart.

* Click Insert > Recommended Charts.

![](/static/mb/chart1.png)

* On the Recommended Charts tab, scroll through the list of chart types that Excel recommends for your data.

Click any chart type to see how your data will look in that format. 

When you find the chart type that you want, click it, and then click OK. We want to select the chart called Line. A line chart is used to display trends over time. We will use the line chart because there are many data points over time. 

Tip: If you don’t see a chart type that you want, click the All Charts tab to see all of the available chart types.

![](/static/mb/chart_title.png)

* Use the Chart Elements, Chart Styles, and Chart Filters buttons next to the upper-right corner of the chart to add chart elements like axis titles or data labels, to customize the look of your chart

![](/static/mb/elements_styles_filters.png)

### ~
Have fun reviewing your simulation and analyze the acceleration by chart the Excel data using Excel.

* Connect the first micro:bit to your computer using your USB cable and run the charting script on it.
* Connect the second micro:bit to your computer using your USB cable and run the charting script on it.
* The first person and second person take turns tilting the micro:bit in the "x" direction while the other player charts the data on the micro:bit!
* Review and analyze the actual micro:bit device acceleration data on Excel
* Display acceleration with y or z using plot bar graph by changing acceleration from "x" to "y" or "z"