Embedded Systems Duration: $2$h$00$

Context

This is a swimming pool management application with devices monitoring characteristics like temperature, pH$,$ and chlorine in different pools at an aquatic center. Each pool has one device that communicates with a central Java server to manage data. There are two types of requests:

Check water quality: For a specific pool over the past week, month, or year.

Store data: Each data entry includes a timestamp, temperature, pH$,$ and chlorine level. Valid ranges are:

Timestamp: seconds since January $1,1970$

Temperature: $-15\mathrm{.}0$ to $35\mathrm{.}0$C

pH: $0\mathrm{.}0$ to $14\mathrm{.}0$

Chlorine: $0\mathrm{.}0$ to $100\mathrm{.}0$ ppm

Assumptions

Each device has an ID $($e$.$g$.,$ "POOL$1")$ identifying the pool.

Data exchanged as lines of text.

Server is single$-$threaded, storing data in maps:

Map$>$ for timestamps,

Map$>$ for temperature, pH$,$ and chlorine.

The server appends new data to the respective maps upon receiving a quadruplet. Its quality$($String poolId, int period$)$ method computes water quality for a pool $(0=$ week, $1=$ month, $2=$ year$).$ Invalid pool ID or period returns $-1$; otherwise, it returns a value from $0$ to $10.$

Protocols

Get Quality: Client sends QUAL id poolid period. Server checks validity; returns ERR error$\_$description for errors, otherwise OK and then water quality.

Store Data: Client sends STORE id timestamp temperature ph chlorine. Invalid data returns ERR error$\_$description, otherwise OK$.$

Microcontrollers $($MC$)$

Q$6.$ Describe an Arduino sketch structure and how it runs post$-$boot.

Q$7.$ Explain Serial.begin$(115200).$

Q$8.$ Provide code to set up a Wi$-$Fi station connecting to poolap with password poolpass, looping until connection is established.

Q$9.$ Assuming a WiFiClient client variable and active Wi$-$Fi$,$ give instructions to establish a TCP connection to server IP $192\mathrm{.}168\mathrm{.}0\mathrm{.}10$ on port $12345,$ looping until successful.

ESP$32$ Dev Board Setup

Pins:

Pin $2($Digital$)$: on$/$off switch $($on $=$ no deep sleep$).$

Pin $4($Digital$)$: LED $($indicates device status$).$

Pins $18$ & $19($Digital$)$: pH sensor $($I$2$C protocol$)$; $1$ byte represents pH $10.$

Pin $22($Digital$)$: Temperature sensor; $1$ byte represents range from $-15$C $(0)$ to $35$C $(150).$

Pin $34($Analog$)$: Chlorine sensor; voltage ranges from $1$V $(0$ ppm$)$ to $2$V $(100$ ppm$).$

Information

On ESP$32,$ analog read returns a value from $0(0$V$)$ to $4095(3\mathrm{.}3$V$).$

To communicate with the pH sensor$,$ the Wire library initializes with Wire phsensor$(18,19).$ Wire offers write$($byte b$)$ and read$()$ functions. Reading the sensor requires writing $1$ byte first, then reading.

For the temperature sensor$,$ the OneWire library initializes with OneWire tempsensor$(22),$ providing a read$()$ function for the current value.

Q$10.$ Provide instructions for setting up read$/$write modes for pins $2,4,18,19,22,$ and $34.$

Q$11.$ Set up an interrupt on pin $2$ to call handleSwitch$()$ when the pin state changes.

Q$12.$ Write the interrupt handler handleSwitch$().$ It checks the switch state: if $1,$ sets nosleep to true and lights the LED; if $0,$ sets nosleep to false and turns off the LED.

Q$13.$ Write the float getPh$()$ function, which retrieves a value from phsensor and converts it to actual pH$.$

Q$14.$ Write the float getTemp$()$ function, which retrieves a value from tempsensor and converts it to actual temperature.

Q$15.$ Write the float getChlorine$()$ function, which retrieves an integer value from pin $34$ and converts it to actual chlorine concentration.

Main Sketch Requirements

Use now$()$ to get timestamp as String.

Use getTemp$(),$ getPh$(),$ and getChlorine$()$ to read respective values.

Send a request to store timestamp, temperature, pH$,$ chlorine for device "POOL$1"$ per protocol.

Read and print server response on Serial.

If nosleep is false, deep sleep for $1$ minute; otherwise, wait $1$ minute.

Q$16.$ Provide instructions to implement the above main sketch steps.

Q$17.$ Battery Details:

Powered by a $3000$mAh battery.

Modified sketch sleeps $3,500$ seconds per hour, active for $100$ seconds.

Power usage: $0\mathrm{.}04$mA in deep sleep, $106\mathrm{.}6$mA while active.

Estimate battery life in hours before depletion, showing computation$$steps$.$

solve this Arduino code please