Ahab3030

Mar 30, 2021 - 05:16

I am trying to make a voltage drop calculator but it keep getting an error message that a string can’t be converted to a float, and when I look in the vars the cm, and con values show up as ‘ ‘. So I am doing something wrong. Please help!
```

importing mods for equation and gui

import ui
import math

setting up view that the sub views can be inside and nameing the view

view = ui.View()
view.name = 'Voltage Drop'
view.background_color = '#ffffff'

Variables E: voltage, L: length, I: amprage, con: conducter material, cm: circular mills of the chosen conducter.

E = str()
L = str()
I = str()
con = str()
cm = str()

attempt at place holder for conductor resistence value

ConLbl = ui.Label()
ConLbl.text = con
ConLbl.name = 'Conducter Value'
ConLbl.x = 155
ConLbl.y = 380
ConLbl.width = 60
ConLbl.height = 20
ConLbl.border_width = 1
view.add_subview(ConLbl)

variables for copper and aluminium

def segment_action(sender):
con = ConLbl.text
if sender.selected_index == 0:
sender.superview['Conducter Value'].text = '12.9'
elif sender.selected_index == 1:
sender.superview['Conducter Value'].text = '21.2'

label for conductor

cLbl = ui.Label()
cLbl.text = 'Conductor'
cLbl.x = 140
cLbl.y = 5
view.add_subview(cLbl)

segmented control for conductor material

cOa = ui.SegmentedControl(con)
cOa.segments = ('Copper', 'Aluminium')
cOa.action = segment_action
cOa.x = 80
cOa.y = 70
cOa.width = 200
view.add_subview(cOa)

label for wire gauge

awgLbl = ui.Label()
awgLbl.text = 'AWG'
awgLbl.x = 165
awgLbl.y = 90
view.add_subview(awgLbl)

attempt at place holder for cm value

cmLbl = ui.Label()
cmLbl.text = cm
cmLbl.name = 'CM Value'
cmLbl.x = 155
cmLbl.y = 410
cmLbl.width = 60
cmLbl.height = 20
cmLbl.border_width = 1
view.add_subview(cmLbl)

segmented control action and variables for wire gauge in AWG

def segment_action2(sender):
if sender.selected_index == 0:
sender.superview['CM Value'].text = '4107'
elif sender.selected_index == 1:
sender.superview['CM Value'].text = '6530'
elif sender.selected_index == 2:
sender.superview['CM Value'].text = '10383'
elif sender.selected_index == 3:
sender.superview['CM Value'].text = '16509'
elif sender.selected_index == 4:
sender.superview['CM Value'].text = '26251'
elif sender.selected_index == 5:
sender.superview['CM Value'].text = '41740'
elif sender.selected_index == 6:
sender.superview['CM Value'].text = '66369'
elif sender.selected_index == 7:
sender.superview['CM Value'].text = '105518'
elif sender.selected_index == 8:
sender.superview['CM Value'].text = '133056'
elif sender.selected_index == 9:
sender.superview['CM Value'].text = '167780'
elif sender.selected_index == 10:
sender.superview['CM Value'].text = '211566'

segmented control for awg selection

awg = ui.SegmentedControl(cm)
awg.segments = ('14', '12', '10', '8', '6', '4', '2', '1/0', '2/0', '3/0', '4/0')
awg.action = segment_action2
awg.x = 15
awg.y = 150
awg.width = 350
view.add_subview(awg)

label for voltage

vLbl = ui.Label()
vLbl.text = 'Voltage'
vLbl.x = 160
vLbl.y = 140
view.add_subview(vLbl)

text feild for voltage input

volts= ui.TextField(E)
volts.x = 155
volts.y = 200
volts.width = 60
volts.border_width = 1
volts.height = 20
view.add_subview(volts)

label for length of wire run

LenLbl = ui.Label()
LenLbl.text = 'Length'
LenLbl.x = 160
LenLbl.y = 200
view.add_subview(LenLbl)

text feild input for length (L)

length = ui.TextField(L)
length.x = 155
length.y = 260
length.width = 60
length.border_width = 1
length.height = 20
view.add_subview(length)

label for amprage

ampsLbl = ui.Label()
ampsLbl.x = 160
ampsLbl.y = 265
ampsLbl.text = 'Amps'
view.add_subview(ampsLbl)

text feild input for amprage(I)

amps = ui.TextField(I)
amps.x = 155
amps.y = 330
amps.width = 60
amps.height = 20
amps.border_width = 1
view.add_subview(amps)

label for result

resLbl = ui.Label()
resLbl.text = 'Result'
resLbl.x = 150
resLbl.y = 420
view.add_subview(resLbl)

label that shows result voltage drop calc

Result = ui.Label()
Result.text = str()
Result.x = 100
Result.y = 500
Result.width = 200
Result.height = 20
Result.border_width = 1
view.add_subview(Result)

function for voltage drop calc performed after inputs and button pushed

def button_tapped(sender):
I = float(amps.text)
L = float(length.text)
E = float(volts.text)
Result.text = (2float(con)float(L)*float(I))/float(cm)

button to run calc after inputs are entered

button = ui.Button(frame=[150, 550, 100, 40], title=' Calculate ')
button.background_color=('white')
button.action = button_tapped
button.tint_color = ('black')
button.border_width = 2
view.add_subview(button)

establishing parent view for child views to present in

view.present('fullscreen') ```

brumm

Mar 30, 2021 - 07:54

con and cm are still string. btw. you shouldn‘t use the same name for str and float values or for global and local values.

cvp

Mar 30, 2021 - 08:45

@Ahab3030 you fill the label.text but not the con variable which stays empty thus not convertible to float.

cvp

Mar 30, 2021 - 09:00

@Ahab3030 and you don't convert the result of the calculation to a string
Try

def button_tapped(sender):
    I = float(amps.text)
    L = float(length.text)
    E = float(volts.text)
    con = sender.superview['Conducter Value'].text
    cm = sender.superview['CM Value'].text
    Result.text = str((2*float(con)*float(L)*float(I))/float(cm))