7 measure the pulse widths and period to verify they

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7.)Measure the pulse widths, and period to verify they are correct Once we are certain that all the timing is correct, write 24-bits to the iLED! 8.)Since we are going to show only one color, we don’t have to send the color data in a forever loop. You can delete instructions from your forever loop (don’t remove the bra forever Loop instruction!!!), and add serial transmission of RGB colors before the forever Loop label. Rewrite your code such that it contains 24 write_0 or write_1 calls (any combination that you choose). Remember that 24-bits = a color. Precede transmission of colors by a long reset signal (longer than 50μs), and remember that you have to make RA0 LOW for the reset. Remember: You wrote delay functions for the prelab. Take some time now and play with the output bit stream. Can you determine a majorerror in the WS2812 datasheet? (HINT: It is on page 5.) 9.)When you are ready, prepare the HTML-based color tag that your TA has requested and demonstrate it to them. Hint: You will need to determine the correct color order and bit endianness of the serial protocol. You can’t always depend on the accuracy of the datasheet! Lab Procedure ChecklistDetermine the color order and endianness of the iLED Have a configurable assembly program that sets the iLED to any of 16M colors Configure and Demonstrate your program and iLED to your TA Lab ReportThis lab will have little in the way of report requirements, the full report will be at the end of Lab2b. But as an interim report, submit your assembly code, and show your delay calculations Page 17
EE 2361 - Lab # 2aECE Department(number of cycles) that you used in your code to implement write_0 and write_1. List any bugs that you had to fix for the iLED to show the colors you wanted. Also list what test patterns you used to test your program (i.e., what combination of write_0 and write_1 you used). Appendix: Reminders about iLEDsNote this is an abbreviated introduction, please see the WS2812 specification, Adafruit page, and EE1301 Device Description for more details. These “iLEDs” are part of a class of devices that are called individually addressableRGB LEDs. This means that contained in each packaged iLED there are three LEDs and a very small LED driver chip with a serial data input. When wired up in a chain, every iLED can be individually set to a different color. Each iLED requires a shared power supply and ground pin. Additionally each iLED has a Data_In and Data_Out pin. When connected in series, the first iLED in the string grabs the first 24-bits (color setting) and then passes the rest of the data to the next iLED down the chain, which grabs the next 24-bits (second color setting) passing the rest of the data on, etc. iLED Pinout DiagramPin Description Note: These devices need +5V power supplies. WARNING: Plugging these iLEDs in backwards (even for a second) will destroy them!!!Page 18

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