Embedded Programming

Reduced Process This Week:

1. Install Arduino IDE
2. Install RP2040 Libraries
3. Write, Test, and Run Code

Tasks This Week:

Group assignments:

Individual assignments:

Below, I walk through some of the notes/screenshots that I have from my work this week and explain my thought process as I was completing my assignments.

I was hoping to be able to work with the actual board for this week, but unfortunately out XTool machine was not working the way that we wanted it to, so my attempts to create a board didn’t work. If they had, then I would have been able to run the same code seen later (in Wokwi) through the actual board. Instead I will show the steps to run the code, and then also the successful code execution in Wokwi.

1. Read the Data Sheet for the RP2040
   
2. Install Arduino IDE onto local machine
3. Install the proper libraries for the Seeed Xiao RP2024
4. Search the board manager and find the RP2024
5. Here, you would normally be able to (and I was hoping to) connect to the board through Arduino IDE and a breadboard. Instead, I will be running the code through Wokwi to simulate the execution on a Raspberry Pi Pico board using the RP2024

Below are two snippets of code that I used and tested to get an LED to flash both quickly and slowly:

#define GREEN 9 void setup() { pinMode(GREEN, OUTPUT); } void loop(){ for(int i=0; i<=10; i++){ digitalWrite(GREEN, HIGH); delay(3000); digitalWrite(GREEN,LOW); delay(3000); } } #define GREEN 9 void setup() { pinMode(GREEN, OUTPUT); } void loop(){ for(int i=0; i<=10; i++){ digitalWrite(GREEN, HIGH); delay(300); digitalWrite(GREEN,LOW); delay(300); } }

As seen above, the difference between the two snippets is that in the first, the delay is at 3000ms, and in the second snippet, the delay is only 300ms.


After experimenting with an LED, I moved on to test the capabilities of an LCD screen using the LiquidCrystal.h library. Below shows a snippet of code and exectution of flashing text on an LCD screen using Pi Pico through Wokwi:

#include <LiquidCrystal.h> LiquidCrystal lcd(12, 11, 10, 9, 8, 7); void setup() { lcd.begin(16, 2); lcd.print("Hello World!"); delay(3000); } void loop() { lcd.clear(); delay(300); lcd.print("Zach Brooks"); delay(300); }


For the group assignment:

6. My lab has a limited selection of microcontrollers, restricting comparison options. Currently available microcontrollers: Seeed Studio XIAO RP2040 and Seeed Studio XIAO SAMD21. Both microcontrollers look similar but have key differences. To compare them, I read their datasheets, identified specifications, and created a comparison table.

   	RP 2040	SAMD 21
   Architecture	ARM	ARM
   SRAM	264 KB	32 KB
   OS	Not Applicable	Not Applicable
   Clock Speed	133 MHz	48 MHz
   Number of Cores	2	Not Applicable
   Flash	2MB	256KB
   Compatible Languages	Micro/Circuit Python, Arduino	Micro/Circuit Python, Arduino
   Pins	11 Digital 4 Analog 11 PWM 1 I2C 1 UART 1 SPI 1 SWD	11 Digital 11 Analog 10 PWM 1 DAC 1 I2C 1 UART 1 SPI 1 SWD

One of the things that could have been improved for this week would have been to be able to run my board using an actual microcontroller and a breadboard. I was planning to do this to be ahead on assignments for the next two weeks as well, but unfortunately, I was not able to get our XTool F1 to work to laser engrave a PCB (and I do not have milling experience yet), so I was not able to make that happen.

Another dramatic that could have been made to my process this week would have been to be better equipped to read a data sheet. I felt really underprepared in reading the data sheet, so it took me much much longer than anticipated in order to complete skimming it, while also gleaming any kind of information from it.

1. Prepare more time for any reading/research for weekly assignments
2. I enjoy the process of using the XTool, but I need to make sure that it works to fabricate a PCB for the final project

• Getting Started with Seeed Xiao RP2040