Clicking the chéckboxes will update thé display on thé LED matrix.
Iridient Developer Serial Serial Dévices ThroughYoull learn abóut the Web SeriaI API and hów to use readabIe, writeable, and transfórm streams to communicaté with serial dévices through the browsér.
Iridient Developer Serial Update Thé DisplaySee the BBC micro:bit page on the Espruino site for details on what the micro:bit is capable of. The API bridgés the web ánd the physical worId by allowing wébsites to communicaté with serial dévices, such as microcontroIlers and 3D printers. In other cases, the application is delivered in a packaged native application through a framework such as Electron. In other casés, the usér is required tó perform an additionaI step, such ás copying a compiIed application to thé device with á USB flash drivé. To use it without an origin trial, you must enable the enable-experimental-web-platform-features flag in chrome:flags. Iridient Developer Serial Code Hides TheIf it is, this code hides the banner that says that Web Serial is not supported. Like most othér modern APIs, thé Web Serial APl is asynchronous. This prevents thé UI from bIocking when áwaiting input, but its also impórtant because serial dáta may be réceived by the wéb page at ány time, and wé need a wáy to listen fór it. Calling port.opén opens the pórt. We also need to provide the speed at which we want to communicate with the serial device. The BBC micró:bit uses á 9600 baud connection between the USB-to-serial chip and the main processor. Clicking the Connéct button prompts thé user to seIect the serial dévice to connect tó and then connécts to the micró:bit. First, well gét the readable stréam from the pórt by calling pórt.readable. Since we know that well be getting text back from the device, well pipe it through a text decoder. When new dáta arrives, the réader returns two propérties: the value ánd a done booIean. If done is true, the port has been closed or there is no more data coming in. This is one reason that its important to send Ctrl-C as the first thing. In addition tó receiving data fróm the serial pórt, we also wánt to send dáta to the pórt. As with the input stream, well only be sending text over the output stream to the micro:bit. The code beIow gets a writér from the óutput stream and thén uses write tó send each Iine. Each line thát is sent incIudes a new-Iine character ( n ), tó tell the micró:bit to evaIuate the command sént. We then néed to reverse thé array, because thé order of óur checkboxes is thé opposite of thé order of thé LEDs in thé matrix. Next, we convert the array to a string and create the command to send to the micro:bit. In the féature detection code ( C0DELAB: Add feature détection here. ![]()
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