Tag Archives: nspire

The Nspire OS 3.2 has arrived !

Hi there ! Good news for Nspire Lua programmers, TI updated the Nspire OS to version 3.2, which is a great update for Lua scripting ! Indeed, it brings, along with some API changes, 2 main things : – An integrated SDK (Software Development Kit) to the Npire Computer Software, which enables you to program in Lua directly within the software. It features some auto-completion, syntax-coloring, a debugger etc. ūüôā

Screenshot of the 3.2 Lua Script Editor
Lua Script Editor

– A Physics Engine… Yes ! You’ll now be able to create some great physics-based simulations for the Nspire, without having to code everything from scratch !


We encourage you to check out the Wiki (we are currently expanding it with the new functions) which has a page that summarizes all the changes to the API in OS 3.2, as well as the official API Documentation from TI. Have fun !

Starting with Lua programming on the Nspire

Hello and welcome to the tutorials index page!

You have several options to learn TI-Nspire Lua programming.

Inspired-Lua hosts several tutorials, but also links to other websites (like Steve Arnold’s). Here are some good resources:

We highly advise you to start…. by the beginning, and for that, click here for A-to-Z TI-Nspire Lua tutorials.

If you want to dive in the theory-based tutorials about Lua on the TI-Nspire, explaining how things actually work, head over here.

However, if you want to directly start Nspire-Lua scripting on a practice-based way, learning by example, you can go there.

Happy Lua programming on the TI-Nspire !

How to have a nice little “input” function in Lua…

(improved version of Nick Steen’s website’s example)

You could be quite surprised by the fact that there isn’t any native way to have a keyboard text input function on the Nspire Lua API. Indeed, it’s a little weird since this is often used for many types of programs (whether in games for typing the username, or other apps to type user data etc.).

Anyway, don’t worry, you can program it yourself with a little piece of code to add to your script ! It actually catches the keypresses with the on.charIn function, and stores what the user types in a string (appending it). You then just have to display this string on the screen and that’s all.

If you want the user to be able to delete some letters, just add some code to the on.backspaceKey function, and that’s all !

In the example below, we set a character limit to 25, but that’s totally up to you.

Well, here’s the complete code ready to be used :

input = ""   
function on.paint(gc)
    gc:drawString(input,5,5,"top")  -- display string
function on.charIn(char)
    if string.len(input) <= 25 then   -- limit of 25 chars
        input = input..char   -- concatenate
        platform.window:invalidate()   --screen refreh
function on.backspaceKey()
    input = string.usub(input,0,-2)  -- deleting last char

Bye !

End of the Nspire Lua Contest

Some time ago, we announced a contest : Nspire programming in Lua . This was a large scale contest since the total sum of the prizes was of about ‚ā¨ 750, including three awesome TI-Nspire CAS CX !

The contest is now over !

With not less than 14 Lua programs submitted, we think this is a great success for a language so “new” on the TI-Nspire calculator!

We would like to thank all participants, regardless of their results!

The judges (Levak, Critor and myself) are going to analyze everything you have done in the coming days, and the results should be there soon !

In the meantime, here is the list (just name + Screenshot) of entries received.

We recall that these programs, unless otherwise stated on the download page are subject to the following license : CC BY-SA 2.0 . Not respecting the terms of this license will result in legal consequences. The authors of the respective programs can change their licence at their will by contacting us by e-mail, of course.

Games : 7

Bobby Carrot – – – – Lo√Įc P.

Labyrinthe – – – – David L.

Reversi (Othello) – – – – Deep Thought.

MasterMind – – – – Nick V.

TI-Cran – – – – Julien R.

Nspired Phoenix Lua – – – – Florent D.

Tactical Wars CX – – – – Rehn C.

Mathematics: 4

TabVar 3 – – – – JayTe.

LuaCS – – – – Jonathan L.

LogoMagic – – – – Jim B.

ABA Logique – – – – Loulou54.

Physics/Chemistry: 3

Planétarium РРРРBastien V.

FormulaOne – – – – Naji A.

Formules de Chimie – – – – Paul J.


Well, while waiting for the results to come, fell free to comment on these programs !

Once again, congratulations to all !

Graphical chemical reaction analysis (Nspire Lua)

(By the way, don’t think that I’m talking about me at the third-person : this is a translation I’ve done of the original TI-Planet article ūüėČ )

Another exclusive TI-Planet program today!

Our dear member Adriweb, after releasing the Chemical Reaction analysis program for TI-83 + / 84 + ( http://tiplanet.org/forum/archives_voir.php?id=1308 ) , has now programmed its Nspire version ! This is a first on this calculator, especially as it profits from the main new feature offered by the OS 3 : Lua Scripting, like the program TabVar 3, presented yesterday.

This .tns document actually consists of two parts:

-> You run the program (TI-Basic) avancement() and follow the steps to provide information on the chemical reaction to be studied.

-> Go to the next tab and watch the table drawn in detail and in color (Nspire CX only) !

A screenshot?


This program is open source and licensed under the Creative Commons BY-SA 2.0.

Source code : https://github.com/adriweb/Tableau-d-Avancement-LUA/blob/master/TableauAvancement.lua

Link the topic of TIPlanet (more info + download ….): http://tiplanet.org/forum/viewtopic.php?f=43&t=8385

Download link directly : http://tiplanet.org/index.php?mod=archives&ac=voir&id=3754

(Click on the “Telecharger” button)

TI-Planet.org : the website that creates smart programs !

By the way, Happy Halloween;-)

TabVar v3, the ultimate function analysis tool !

Hi everybody,

Today is a great day!

Indeed, for the lucky owners of a TI-Nspire with OS >= 3, JayTe has made an awesome program that combines the simplicity of the TI-Basic with the power of Lua, for our pleasure …
Here is … TabVar 3 !
Yes, the famous program that makes all your work in depth and draws a beautiful variations table (“Tableau de variations” in french), the perfect function analysis tool !!

“Hmm, Doesn’t that exist already ?” You might say.
It does, actually, The idea is not new.
Chronologically, it has indeed been made by Adriweb, the first one for Nspire, and then, TabVar v1 and v2, by JayTe, whose engine is based originally on Adriweb’s program, but everything was done much further by integrating more and better function analysis functions and algorithms.

This program exceeds by far its competitors. No other .tns could can hope to compete so far.

The outstanding feature of this version is that this program (launched exclusively on TI-Planet) deeply uses the features offered by the OS 3 by integrating a dynamic Lua script for an optimal view of the variation table, which for once is completely graphical. No need to have weird graphical hacks to correctly display what we need …

We will not make you wait any longer… Here’s a screenshot of TabVar:

and details of preliminary calculations (click for larger image):

So far, you will not find a more reliable engine (although nothing is perfect, of course, complex functions can be studied incompletely …)
You can, for example, try fairly complex functions, such as polynomial, rational, with or without asymptote(s) and strange behavior with or without limits …
In short, for a high school student (or other!) It’s more than perfect ūüôā

Download link: http://tiplanet.org/forum/archives_voir.php?id=3751

Thank you Who?
Thank you Jayte!

Do not forget, this program is by far the most reliable and practical for the studies of functions ..
A small screenshot to prove that point ?
(Example : TabVar v3 against a competitor for the same function f(x)=1/x)

Yep, do not trust bad imitations if you want a good grade!

TI-Planet.org, the reference website to find everything you need and what you dream of!

Great TI-Nspire Lua Contest 2011

The contest is now over, thanks to everybody who participated !


The websites Inspired-Lua and TI-Planet, with our partner R. JARRETY (where you can order your TI calcs with great TI-Planet prices), are organizing a new, great contest  in  a scale never seen before !

First, for the first time in the history of our site, the competition crosses the borders of France and whatever your country of residence, you can take part in it !

Moreover, the prize is absolutely amazing and unprecedented :
-> 3¬†TI-Nspire¬†CAS¬†CX <- , so that’s three times more likely¬†to win!


No, you’re not dreaming !

You only have to create a Lua program for TI-Nspire in connection with one of these three categories:

  • Mathematics
  • Physics and Chemistry
  • Games

You’ll need¬†an Nspire OS (or software) 3.0 or later (preferably 3.0.2 – see links).

The only requirement is that your program is suitable for a French user. If your program displays text, use single common words in a foreign language is tolerated.

Use Google Translate if needed.

To participate, simply send an email to    info @ tiplanet . org by November 7th, 2011 23:59 GMT +2 (DST French) with these information :

  • your full name
  • your full address
  • a valid email address
  • which is *only* used to send your reward

  • the chosen category
  • an¬†archive¬†as an attachment

The attached archive will contain:

  • the program¬†format ‘tns’
  • source code
  • a description in¬†a¬†file ‘readme.txt’
  • possibly¬†documentation¬†(format and¬†contents are free)

You can submit only one program for the competition, so you can participate in only one category. Choose the right one wisely !

However, it is perfectly possible to update an already submitted or even change the program or the category you chose just by sending a new email to participate, since only the last one received will be taken into account.

Good luck to everybody !


Official Rules
Inspired-Lua (documentation & Lua ressources)
TI-Planet (help & resources)
Lua generator, “Luna”
OS 3.0.2 for TI-Nspire
OS 3.0.2 for TI-Nspire CAS
OS 3.0.2 for TI-Nspire CX
OS 3.0.2 for TI-Nspire CX CAS
TI-Nspire 3.0.2 Software student for PC (free for 30 days)
TI-Nspire 3.0.2 Software student for Mac (free for 30 days)
TI-Nspire 3.0.2 Software teacher for PC (free for 90 days)
TI-Nspire 3.0.2 Software teacher for Mac (free for 90 days)

Object Classes

Back to part 4

In this part, we will talk about a quite interesting and useful topic in Nspire Lua programming, which relies on working with “objects” instead of (or in addition to…) classic variables.

If you already have some Lua knowledge, you should know that it is using a lot of key-indexed or key/value tables. This means that each element of a table (or list) is linked to a key that lets us to refer with. For example the table below is key-indexed with strings :

tab = {"cle1"="valeur1", "cle2"="valeur2"}
print(tab["cle1"]) -- va afficher "valeur1"

In Lua, keys are polymorphic, that way we can easily store strings, tables or functions as key or as value :

tab = {
  [function() return 3 end]="table",
for k, v in pairs(tab) do
  print(k, v)

Will display :

1                 exemple
2                 de
function: 10f6840 table
false             polymorphe

Even the Lua global environment (_G) is a table.

It’s in this way we’re going to introduce Lua object-oriented-programming (“OOP”) : Each object is a table and each object has multiple elements named methods or properties. In the future if we would like to create a new object we simply duplicate the table from its meta-table. If we would like to create inherited objects, we will also duplicate its meta-table and change it a little bit to make it different from the main object.

myObject = {
    ChangerNom=function(self, nom)
        if #nom > 1 then
            self.nom = nom
    ChangerAge=function(self, age)
        if age > 1 then
            self.age = age

We can easily access/write stuff on any element. For example :

print(myObject.age) -- affiche 21
myObject:ChangerAge(18) -- identique à myObject.ChangerAge(myObject, 18)
print(myObject.age) -- affiche 18

You have to understand that there is no such thing as private/public things in Lua as you could find in C++/C#/Java…, since this is just a representation, and not a real implementation. So it can be easier in Lua, especially for beginners.

You can now understand why you call¬† platform.window:width()¬† this way, and not with a global function such as¬† “GetWindowWidth()”.¬† In fact, width() is a method of the window object, which itself is a property of the platform object. Same thing for platform.gc() which we can find shortened as ‘gc‘. Actually, gc is an object and platform.gc() is its “constructor”.
In one hand, it’s pretty much the same thing (they both have the same methods), but in the other hand, they have some differences (some of their properties aren’t the same).
(NB : In Nspire Lua code, try to avoid using gc by calling platform.gc(), because of some unexpected behaviors you can get if you don’t know exactly what you’re doing. You should always use the gc that the on.paint(gc) event provides as a parameter)

Let’s tell you what classes look like in code and how to create them.

In the Nspire Lua API, we can find a “class()” method, that usualy doesn’t come with Lua. In fact, this method was created to help programmers create their class by having a much easier and shorter way to do it. For the curious people among our readers, here’s what we would have to do to create and use a class without the class() method (here, for the “Account” class).
(it can be scary if you don’t know Lua well – you can skip this paragraph if you want)

Account = {}
Account.__index = Account
function Account.create(balance)
    local acnt = {}             -- our new object
    setmetatable(acnt,Account)  -- make Account handle lookup
    acnt.balance = balance      -- initialize our object
    return acnt
function Account:withdraw(amount)
    self.balance = self.balance - amount
-- create and use an Account
acc = Account.create(1000)
More info here : http://lua-users.org/wiki/SimpleLuaClasses

Now, with the Nspire Lua API, with  class() :

Account = class()
function Account:init(balance)
    self.balance = balance      -- initialize our object
function Account:withdraw(amount)
    self.balance = self.balance - amount
-- create and use an Account
acc = Account(1000)

That’s much better, right ?

Here, “init()” is the constructor. You *have* to have an “init(…)” method for your classes since it’s written that way in the class() method. The init(…) function will be the one that will be called when your objects are going to be created.

We are going to show you a real example of OOP programming in Lua, by creating a script that will create a class, called “Shape”, which will have several methods including a constructor allowing us to creates shapes.

Forme = class()
-- Constructeur
function Forme:init(x, y, image)
    self.xpos = x
    self.ypos = y
    self.pic = image
-- Dessiner la forme
function Forme:paint(gc)
    gc:drawImage(self.pic, self.xpos, self.ypos)
-- Repositionner l'objet en indiquant les nouvelles coordonnees
function Forme:setxy(newx, newy)
    if newx > xmin and newx < xmax and newy > ymin and newy < ymax then
        self.xpos = newx
        self.ypos = newy
-- Repositionner l'objet en indiquant le deplacement a effectuer
function Forme:move(dx, dy)
    local newx,newy
    self:setxy(self.xpos + dx,self.ypos + dy)

You may have noticed the use of global variables like xmin, xmax. These are defined earlier in the script, without . For example :

xmin = 20
ymin = 30
xmax = 250
ymax = 200

We can now play around with our “Shape” class. We’re now going to create two images and convert them into TI.Images using the official developement tool :

carre_rouge = image.new("\010\000\000\000\010\000\000\000\000\000\000\000\020\000\000\000\016\000\001\000\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252\227\252")
smiley = image.new("\016\000\000\000\018\000\000\000\000\000\000\000 \000\000\000\016\000\001\000\156\243\156\243\156\243\189\247\213\222\235\193\136\181g\181\135\181g\181\137\185O\202\189\247\156\243\156\243\156\243\156\243\156\243{\239O\206\168\222F\243D\243d\247d\247#\243\004\235E\214\170\1858\231\156\243\156\243\156\243\213\222m\210\231\230d\247\132\251\195\255\131\255\131\255\131\255C\251\003\247\132\226\233\193r\210z\239\156\243\204\189\198\226\132\247\166\218\007\198\198\226\195\255\131\255#\243\231\197\007\198\002\251\131\230\135\185\246\222\212\218g\210D\243\166\218\166\218\197\226D\239\131\255\131\255C\247\165\218d\222\006\206\194\242\196\205O\206\170\185\005\239\131\255\197\226D\239\131\255\131\255\131\255\131\255C\251\034\255\002\255E\218\226\250b\234\167\193G\173C\247\131\255\131\255\130\218\001\198\162\222\131\255c\251\002\243\161\197\161\197\226\250\226\250\162\246\133\193f\181#\243C\251\131\255\194\193\194\156\002\202C\251\034\255\162\234\194\156\194\156\193\250\193\254\193\254\133\193g\181\003\247c\251\034\255\196\230e\218\196\234\034\255\034\255\226\242%\218%\218\226\250\226\250\161\254\133\193&\169\226\242\034\255\034\255\034\255\034\255\034\255\002\255\002\255\193\254\193\254\226\250\161\254\161\254\161\254d\189G\173\163\234\002\255\226\242\194\242\163\234\162\242\162\242\162\242\130\238\130\242B\242\130\242\162\246B\242\133\193\014\198E\214\194\242f\181\198\156\231\156\231\156\231\156\231\156\231\156\231\156\198\156\231\156B\242\227\213\235\197Y\235\136\185\130\238\193\254\132\189s\206\222\251\222\251\222\251\222\251{\239\198\156\130\242\129\254d\189\179\214\156\243\237\193\196\205\162\242\162\242\198\201)\165)\165)\165)\165H\173B\242\129\254\227\213\169\193\023\227\156\243z\239\137\185\034\226\162\246\130\242B\234\034\230\034\230B\234\034\234\129\254\130\242D\181\213\222\156\243\156\243\156\243\023\227\201\197\002\222\162\246\161\254\129\254\161\254\129\254\129\250\034\234d\189\147\214\156\243\156\243\156\243\156\243\156\243\246\222\011\206\196\205\002\222B\238\034\238\034\230\196\209\165\197\147\214{\239\156\243\156\243\156\243\189\247\156\243\156\243\023\227p\210\011\206\198\205\198\205\232\205O\210\147\214\156\243\156\243\156\243\156\243")
forme1 = Forme (xmin + 20, ymin + 20, smiley)
forme2 = Forme (xmax - 30, ymax - 30, carre_rouge)

You can see how we’re not explicitely calling the init() constructor of the Shape class.
In fact, we just have to call Shape(…) and the init will be called with the arguments.

Now we just have to create the main structure of the lua script, with the basic events you should know by now. Here’s what it looks like :

-- Affichage
function on.paint(gc)
    gc:setColorRGB(231, 231, 231)
    gc:fillRect(xmin, ymin, xmax-xmin+15, ymax-ymin+15)
    gc:setColorRGB(0, 0, 255)
    gc:setFont("sansserif" , "b", 11)
    x = gc:drawString("(" .. forme1.xpos..", ".. forme1.ypos .. ")", 50, 0, "top")
-- Permet de deplacer forme1 avec les fleches directionnelles
function on.arrowLeft()
    forme1:move(-5, 0)
function on.arrowRight()
    forme1:move(5, 0)
function on.arrowUp()
    forme1:move(0, -5)
function on.arrowDown()
    forme1:move(0, 5)
-- Permet de choisir l'emplacement de forme2 avec la souris
function on.mouseDown(wx, wy)
    forme2:setxy(wx, wy)

Here’s what you get !

Have fun !

NB : you can find examples of classes and OOP programming in real games programmed in the Nspire Lua API. For instance : the BreakOut game by Adriweb, which uses different classes to have objects such as the ball(s), the blocks, the paddle, the bonuses etc.

Using a predefined variable in a TI-Nspire document

Back to part 3

This part will show you how well the Lua language is integrated in the TI-Nspire framework.
For this, we’re going to study the var API and expected events.

Retour à la partie 3

Cette partie vous montrera que le Lua est bel et bien en parfaite harmonie avec la TI-Nspire et son framework. Pour cela nous vous proposons d’√©tudier l’API var et les √©v√®nements qui en d√©coulent.

Tout d’abord , cr√©ez un nouveau classeur TI-Nspire et d√©finissez y une variable n, par exemple un curseur permettant d’en faire varier la valeur entre 0 et 10 ou directement dans la page de l’application calculs.

C’est cette variable que nous allons r√©cup√©rer dans le script Lua !

Pour cela, cr√©ez un nouveau fichier Lua avec votre √©diteur de texte pr√©f√©r√© et nous allons commencer √† le remplir.

L’API var permet de faire pleins de choses int√©ressantes et nous allons les √©tudier.

Tout d’abord, notre script doit savoir si la variable n change. Nous trouvons donc cette ligne :


-- On indique ici qu'il faut surveiller le contenu de la variable n

Au passage, nous pouvons √©crire une fonction r√©cursive qui renverra la factorielle d’un nombre, rien que pour l’exemple :

function factorielle(n)
	if math.floor(n) < n or n < 0 then
		return ("Erreur")
	elseif n == 0 then
		return(n * factorielle(n - 1))

Maintenant, nous allons nous int√©resser au couplage des √©v√®nements. Il nous faut deux √©v√®nements. D’abord celui pour dessiner √† l’√©cran, c’est √† dire on.paint(), mais √©galement un √©v√®nement d√©clench√© lorsque notre variable change. Cet √©v√®nement est on.varChange() et est lanc√© chaque fois qu’une variable appartenant √† la liste des variables surveill√©es (avec var.monitor()) est modifi√©e.

function on.varChange(varlist)
	-- On provoque une reactualisation de la fenetre

Concr√®tement, d√®s qu’une variable surveill√©e change, on demande √† ce que l’√©cran soit actualis√©. Donc maintenant, il faut faire cette partie d’affichage en cr√©ant la fonction on.paint(). En effet, appeler platform.window:invalidate() marque l’√©cran comme “invalide”, donc bon √† √™tre actualis√©. Au prochain tour de boucle de processus, comme l’√©cran doit √™tre actualis√©, le framework de la TI-Nspire lancera la fonction on.paint()

function on.paint(gc)
	local wh, ww, n, x
	-- nombre de pixels (hauteur et largeur)
	wh = platform.window:height()
	ww = platform.window:width()
	-- affichage d'un trait de separation
	gc:setPen("medium", "smooth")
	gc:drawLine(0, 60, ww, 60)
	-- affichage de la taille de la fenetre en bas de l'ecran
	-- il s'agit juste d'un exemple !
	gc:setColorRGB(200, 200, 200)
	x = gc:drawString(wh, 10, wh - 10, "bottom")
	gc:drawString(ww, x + 10, wh - 10, "bottom")
	-- affichage de n!
	n = var.recall("n")
	if math.floor(n) < n or n < 0 then
		gc:setColorRGB(255, 0, 0)
		gc:setFont("sansserif" , "b", 10)
		gc:drawString("n n'est pas un ",10,10,"top")
		gc:drawString("entier naturel ",10,25,"top")
		gc:setColorRGB(0, 0, 255)
		gc:setFont("sansserif" , "b", 20)
		x = gc:drawString(n.."! = ", 10, 10, "top")
		x = gc:drawString(factorielle(n), x + 5, 10, "top")

Voil√† ! C’est tout !

Lancez ensuite TI-Nspire Scripting tools et cliquez sur le premier bouton (ou choisissez tools, Lua Script to Clipboard) puis s√©lectionnez le fichier contenant le script que nous venons de cr√©er. Allez dans le logiciel TI-Nspire, et utilisez Ctrl V pour copier le code Lua.

Faites ensuite varier la valeur de n, et la miracle !

La valeur dans la fenêtre Lua est actualisée !

Tip : Si vous avez modifi√© le script, il vous suffit dans TI-Nspire Scripting Tools de

  • cliquer sur le second bouton (ou choisissez tools, Reload Script).
  • Allez ensuite dans le logiciel TI-Nspire, cliquer sur la fen√™tre correspondant au code Lua.
  • Ctrl K pour s√©lectionner cette fen√™tre
  • Ctrl V pour copier le nouveau script Lua

Id√©es d’am√©liorations :

Vous pouvez tester une premi√®re “am√©lioration” de ce script en ajoutant les lignes suivantes, permettant de “piloter” n avec les touches “vers le haut” ou “vers le bas” :

function on.arrowUp()
	var.store("n", var.recall("n") + 1)
function on.arrowDown()
	var.store("n", var.recall("n") - 1)

>> Partie 5

Concepts and Basics

This part will explain you how the Lua actually works inside the OS and help you to figure out what you’re doing when you write a script for the TI-Nspire. It is recommended to have some basics on Lua programming or some knowledge of event-driven languages, but keep in mind that it is not required.

The Lua is an interpreted script language which means that it isn’t as fast as ASM/C programs, but is still better than the TI-BASIC. One good thing is that this language is in a complete harmony with the OS with basic events and a powerful graphic context.

Lua is normally a sequential script language. For example, when we use the print() command to display a value, we can easily guess when the command will be run in the script. Here’s an example :

a = 1
a = a + 1

Output :


Nothing special. However, on the TI-Nspire, Lua has a completely different approach. We meet this approach with high-level programming or with object-oriented languages (like C++, C#, …). In those languages, we don’t have the ability to control the flow/execution of any function. Yes, it can be quite strange to hear that, but it’s the way it is. Are we going to learn a language that doesn’t do what we tell it to do ? Well, in a way, yes.

But don’t worry ! We’re here to learn how to cross this quite unstable bridge ! A wonderful world is on the other side.

First of all, you have to “change team”. As in before, you were the boss, this means you used to tell the machine to compute 1 + 1 and it would proudly output “2”. Now, you are a worker. A task authorization is given to you, thus, you explain to the machine how to do this work. Actually, those “authorizations” are called events. When the event is called, you can do what ever you want. Here is a pseudo-code explaining what to do when the “Cook” event is called :

function Cook()

You can easily understand that you won’t cook when you get the job. You’ll wait for¬†your boss’ order ! Well, it is exactly the same thing between the TI-Nspire and you. But this time, the TI-Nspire framework is the boss. Everything is event-based.

In a nutshell, our functions have to be called by the TI-Nspire. But how to be sure that they will be executed ? It is the moment to look at the Events list. When an event is fired, the TI-Nspire gives zero, one or multiple parameters (“arguments”) that we can use in our function. This lets us know, for example, which key has been pressed, because when the TI-Nspire executes the charIn(ch) event, it gives also a string as an argument corresponding to the key. However, when the enterKey() event is fired, no argument is given.

Before, in a non-event-based language (like BASIC, C, PHP …) we used to program like this :

-- Init Constants here
k = 0
while k == 0 do
	k = getKey()
if k == 72 then
	-- do something

Now, it looks like that :

-- Init Constants here
function on.charIn(ch)
	if ch == "7" then
		-- do something

We hope you understood that very important part…


Let’s go to Part 2 now !