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 Computer Math and Games in Pascal (preview) Lazarus Handbook

### Author Topic: Project: LED Calculator (LedCalc)  (Read 6133 times)

#### ArndtB

• New Member
• Posts: 13
##### Project: LED Calculator (LedCalc)
« on: March 29, 2017, 12:27:45 pm »
Hello together,

I want to share my small Tool LED Calculator (LedCalc) with you, realized with FreePascal and Lazarus, licensed under GPL-3.

LED Calculator (LedCalc) is a small, cross-platform graphical tool to calculate resistor values for single LEDs. Helpful for beginners to calculate and choose the correct resistors for own electronical projects and experiments with light-emitting diodes (e.g. for Arduino, Raspberry Pi or something else). This program was written in FreePascal 2.6.4 supported by the IDE Lazarus 1.4.4.

http://git.braier.net/ArndtB/LedCalc

I hope you like the program and it will be useful for you. For your suggestions, praise and criticism as well as any kind of feedback I am always open, please write me here, on GitHub or an email at dev@braier.net.

Thank you for your Feedback

« Last Edit: June 29, 2018, 05:39:18 pm by ArndtB »

#### wp

• Hero Member
• Posts: 7933
##### Re: Project: LED Calculator (LedCalc)
« Reply #1 on: March 29, 2017, 12:58:24 pm »
Nice.

An interesting extension for the engineer would be: You will not be able to buy a resistor having exactly 193.33 ohms, you only can buy resistors with discrete values. The series E24 with a tolerance of 5%, for example, has values 1.0, 1.1, 1.2, 1.3, 1.5, 1,8, 2.2 etc. (see http://www.logwell.com/tech/components/resistor_values.html). Your program could select the nearest value from this series, and calculate the variation of power loss and LED current within the tolerance limits.
Mainly Lazarus trunk / fpc 3.2.0 / all 32-bit on Win-10, but many more...

#### Edson

• Hero Member
• Posts: 1124
##### Re: Project: LED Calculator (LedCalc)
« Reply #2 on: March 29, 2017, 07:38:48 pm »
Good.

And yes, the resistors have standar values, so it would be better if the program gives this standar value (closer) and standar values of power.
Lazarus 2.0.10 - FPC 3.2.0 - x86_64-win64 on Windows 8

#### avra

• Hero Member
• Posts: 2081
##### Re: Project: LED Calculator (LedCalc)
« Reply #3 on: March 29, 2017, 10:20:44 pm »
Cute
ct2laz - Conversion between Lazarus and CodeTyphon
bithelpers - Bit manipulation for standard types
pasettimino - Siemens S7 PLC lib

#### Graeme

• Hero Member
• Posts: 1430
##### Re: Project: LED Calculator (LedCalc)
« Reply #4 on: March 30, 2017, 04:47:19 pm »
Very nice ,and will definitely be useful for beginners. Thanks for sharing.
--
fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal
http://fpgui.sourceforge.net/

#### eny

• Hero Member
• Posts: 1617
##### Re: Project: LED Calculator (LedCalc)
« Reply #5 on: March 30, 2017, 09:03:46 pm »
Cute
Hehe this is also what I thought.
Cute little program
All posts based on: Win10 (Win64); Lazarus 2.0.10 'stable' (x64) unless specified otherwise...

#### AnthonyTekatch

• Jr. Member
• Posts: 65
##### Re: Project: LED Calculator (LedCalc)
« Reply #6 on: March 31, 2017, 12:18:19 am »
Nice!

You might be able to remove the calculate button if any changes are made then automatically execute the calculate code.
« Last Edit: April 01, 2017, 02:16:31 pm by AnthonyTekatch »

#### ArndtB

• New Member
• Posts: 13
##### Re: Project: LED Calculator (LedCalc)
« Reply #7 on: April 01, 2017, 01:49:19 pm »
Hello together,

thank you all for your great feedback and proposals, I'm very happy about that. I will take this points and try to implement them

Many greetings and have a nice day

#### ArndtB

• New Member
• Posts: 13
##### Re: Project: LED Calculator (LedCalc)
« Reply #8 on: June 29, 2018, 05:39:50 pm »
Hello together,

LedCalc has moved and is now available here:

http://git.braier.net/ArndtB/LedCalc

#### fred1933

• New member
• Posts: 9
##### Re: Project: LED Calculator (LedCalc)
« Reply #9 on: June 29, 2018, 08:03:28 pm »
Hello,
nice program, but be carefull Vf values are not all identical in a class of the same color. By exemple, you can find a blue Led with Vf=2.65V and another one with Vf=3.7V. In any case, it is always recommended to put a resistance in series with a led to limit the current and preserve the Led.