 # Z- Score analysis for sensors connected using arduino by uart

Hi Guys!

Currently i am working upon a project that contains the sensors connected bolt iot via uart as mentioned in the Docs site! by hardware interfacing. I had uploaded this code in my Arduino Uno.

Now, My requirement is to calculate the Z-score analysis for the sensors connected via the Arduino. I had connected the following sensors in the respective pins at Arduino.

1.LM35 - A0
2.LDR - A1
3.Moisture sensor. - A2.

So, Generally procedure taught in the lecture was reading the sensor value which is connected in the bolt iot module => A0 pin by using the Bolt Python library and code running in a ubuntu server. The code in the lecture to read the value from bolt A0 pin was below.

## Code:

``````    import conf, json, time, math, statistics
from boltiot import Sms, Bolt
def compute_bounds(history_data,frame_size,factor):
if len(history_data)<frame_size :
return None

if len(history_data)>frame_size :
del history_data[0:len(history_data)-frame_size]
Mn=statistics.mean(history_data)
Variance=0
for data in history_data :
Variance += math.pow((data-Mn),2)
Zn = factor * math.sqrt(Variance / frame_size)
High_bound = history_data[frame_size-1]+Zn
Low_bound = history_data[frame_size-1]-Zn
return [High_bound,Low_bound]

mybolt = Bolt(conf.API_KEY, conf.DEVICE_ID)
sms = Sms(conf.SSID, conf.AUTH_TOKEN, conf.TO_NUMBER, conf.FROM_NUMBER)
history_data=[]

while True:
response = mybolt.analogRead('A0') //==> What code to replace to fetch the values from the Arduino for manipulation?

if data['success'] != 1:
print("There was an error while retriving the data.")
print("This is the error:"+data['value'])
time.sleep(10)
continue

print ("This is the value "+data['value'])
sensor_value=0
try:
sensor_value = int(data['value'])
except e:
print("There was an error while parsing the response: ",e)
continue

bound = compute_bounds(history_data,conf.FRAME_SIZE,conf.MUL_FACTOR)
if not bound:
required_data_count=conf.FRAME_SIZE-len(history_data)
print("Not enough data to compute Z-score. Need ",required_data_count," more data points")
history_data.append(int(data['value']))
time.sleep(10)
continue

try:
if sensor_value > bound :
print ("The light level increased suddenly. Sending an SMS.")
response = sms.send_sms("Someone turned on the lights")
print("This is the response ",response)
elif sensor_value < bound:
print ("The light level decreased suddenly. Sending an SMS.")
response = sms.send_sms("Someone turned off the lights")
print("This is the response ",response)
history_data.append(sensor_value);
except Exception as e:
print ("Error",e)
time.sleep(10)
``````

In the above code need to replace the line highlighted that is [mybolt.analogread(‘A0’)].So, what to do now to get the values from the Arduino Analog pins ?and do the z-score analysis.

Help me to sort it out by giving a resolution! @vinayak.joshi@shoeb.ahmed
Thanking you for spending the time here!

Hi @arjunraj,

First of all you will have to upload the following code to the Arduino to get the analog data.

Then in your python code, you will have to replace “response = mybolt.analogRead(‘A0’)” with 2 statements.

``````    mybolt.serialWrite("GetAnalogData")
``````sensor_value = int(data['value'].split(","))