If you arethinking of doinga projectwithArduinoUNOandneed toview datawithout having toshow them through a serialorUSBport on your computer, you’ll need a small screen ordisplay.Let’s seehow to use aTFT1.8″ by SPI. It is not designed for use withan ArduinoUNOso itsI/Oports do not work 3.3Vbut 5V. What itallowsis poweredat 5V, in factif wefeed itto 3.3Vfor use withan ArduinoNanoor3VTrinkethave toshort theJP1connectionto notusethe voltage regulatorthat powersboth theTFTastheSDcard. In this casewe will not usetheSD ,
Alimentation(VCC, GND): By defaultmust be connected to5V,but ifwe short-circuitJP1we have tofeed3.3V.
Backlighting (LED+, LED-):Weconnectto 3.3V(LED+) and 0V(LED-), but this waywe can notcontrol the intensity. A good waywould be to usea circuit with atransistorcontrolled byPWM, so that by varyingthe duty cyclegivethe feeling ofa variationin the intensityof light,whenyou are actuallyturning off and onseveral times per second, according tofrequencywe choose.
Toconnect totheTFTto anArduinoUNOhave to changethe levels5V to3.3Vwith74HC245.
Before connecting, we must see settings thatwe have to useon74HC245. Keep inmind thatportAnis3.3Vand port Bn5V.In additionthe masterSPIisArduino UNOsoBnmust beAninput sooutputbeingA=B. To operatein this waythesettings are/OE=LDIR=L.
The connection withArduino UNOis the following(Click on image tohigher resolution).
When everything isconnectedas inthe scheme, we load our first testinArduinoUNO, We will needto have installed theAdafruit_GFXandAdafruit_ST7735libraries.Asample codeto startcan be this:
If you‘ve ever wanted to install aTTS(Text to Speech)and have notknown how, I proposea simpleway to useGoogleTTSon Linux. The most common isto install anaddonon your browser,buthave thelimitation ofnot being able touse it in aPDFora text file. This wayyou can use itregardless of which program you areusingjusthighlightingthe text youwant to hearand pressinga key combinationof your choice.
Firstwe will installthesay.shscript, you can download itfrom here ormake aclonewithgit. Before youcreatea folderfor ourscriptin ourhome.
git clone https://gist.github.com/873364.git
Ifyou’ve everbeen lookingforArduinolibrariessureyoufinished inGitHub.Thiswebrepositoryhas thousands oflibraries that canbe veryuseful forour projectswithArduino. Let’ssee acouple ofways to installa library thatishosted onGitHub.For this exampleI chosetheaJsonlibrary. In the first placewe will see howa manual installationwould be done, for which we need to downloadthelibrary ina ZIPclicking the Download ZIPbutton insidethe project page.
Once downloadedif we try toaddthelibraryusing the drop-down menuImportSketch>>Library…>>Add Library It will givean error becauseArduinoIDEsupports onlyASCIIcharacters infile namesof libraries andGithubaddeda“- master“ at the endof the name,bothZIPand theproject folder. The problem is that the ‘-‘ character not supported . Therefore we have to extract the ZIP by hand in the libraries folder of your sketchbook(in Ubuntu is in the user home, in ~/sketchbook/libraries/). Once extracted we need to rename the folder by removing all non-ASCII characters, in most cases just remove the “-master” final and it will be ready to use. When we return to open Arduino IDE and librarywill be available in our sketchbook.
Another way to install the library is bygit. Ifyou havenotyetinstalledwhatyou can do itusing theUbuntuSoftware Center or using thefollowing command Instruction:
sudo apt-get install git
If you already havegit,toinstall the libraryjust open aterminal, go to~/sketchbook/libraries/folder andmake acloneoftheURLof the project, you can findjust above the downloadZIPbutton.
git clone https://github.com/interactive-matter/aJson.git
The easiest and popular way to introducing us to the world of microcontrollers is using Arduino. The greatadvantage overother development platformsis itssimplicity and above allthe supportyou have from yourcommunity.Thefact that it isan open-sourceproject opens upendless possibilitiesfor customization,as you haveaccess toall design,from electronicsto software.
ButArduinois not only ahardwarealso need asimple and friendlyenvironmentprogrammingfor everyone, including those who haveneverprogrammed. That environmentisArduinoIDE.
The open-source Arduino environment makes it easy to write code and upload it to the i/o board. It runs on Windows, Mac OS X, and Linux. The environment is written in Java and based on Processing, avr-gcc, and other open source software.
Install in Ubuntu
The easiestand safest way toinstall itis through theUbuntusoftware centerlookingforArduinoand clicking on theinstallbutton.
Butwe can alsoinstall itusing the consoleas follows:
sudo apt-get install arduino
If we wantedthe latest beta version, although notrecommended if you wanta stableand with the greatestpossibleerrordebuggingversion. To installusethe following instructions:
Following theappearance ofArduinoincreased the number ofopen-source hardwaredevicesto developaffordableto the general public. An example isProTrinket andTrinket,that likeArduino has aATmega328microcontrolleranda bootloader thatallows you to load your programsdirectly tothe boardvia USB.Butthe outstanding featuresare itsability to connectdirectly to a batteryfrom5vto15v(in the case of theV3trinketfrom3.5vto16v) and especiallyits small size.All thismakes it idealforsmall projectsthat run witha battery.We canalsoload programsthrough theArduinoIDEand 95% of Arduinoprograms designed torun onTrinketdirectly,the resthave tochange the settings forsome pinsor not enoughspace for storage in other cases.
Touse withArduinoIDEwe have tomake asmall modification to theboards.txtfile in theinstallation directoryArduinoIDE, which is in/arduino/hardware/boards.txt. In the case ofUbuntuare in:/usr/share/arduino/hardware/boards.txt
To change thisI will usegedit, but you can useanytext editor.Root permissionsare neededfor editing, so we have to usesudo.
The originof the Pythagorean theoremis a mystery, in fact it is not knownifit was discoveredonce or severaltimes indifferent places.The question is, would it be difficult todeduce? Belowyou can viewan animation witha graphic demonstrationof the Pythagorean theorem. You will be surprisedwhat you do notexplainitthis way before…