Breaking problems down into smaller bits really helps to make a solution. The process doesn’t have to be linear like what you see below. Often working on one sub-problem helps to give a better conceptual understanding of the whole, so jumping back and forth between sub-problems is natural (despite it not seeming that way).

Exercise 3b: Make a flash simulator

To figure out where to start, list out the super basic elements. There’s gonna be an array, and the minimum functionality is to read, write, and erase. 

Here’s the steps of breaking the problem down into sub-problems, and the sub-problems into further smaller sub-sub-problems. Below this list are my notes. Coding was only done at the very end. The majority of time was figuring out the problem, reading the documentation, and of course - learning!

Breakdown

Step 0: Getting background information

• Downloading the datasheet
• Understanding the block diagram
• Figuring out the nesting… flash, block, sector, page

Step 1: Determining the buffer

• Initializing an array
• Setting its vals and checking max values
• Pointer review

Step 2: Determine the address

• Do not follow this! It is actually not needed, I went down a complete rabbit hole of confusion with this

Step 3: Code the buffer

• Get the coding down right for passing it to functions, reading, writing
• Make a sample test to understand

Step 4: Make erase function

• Review documentation
• Pseudo code
• Find Instruction commands
• Also make the init function (unrelated to erase)

Step 5: Make read function

• Review documentation
• Pseudo code
• Find Instruction commands

Step 6: Make write function

• Review documentation
• Pseudo code
• Find Instruction commands

Step 7: Make test flow

• Based on the test description in the book Making Embedded Systems by Elecia White

Step 8: Make tests to fail

• Brainstorm edge cases and ways it would not work

Step 9: Code it

• Code it, compile it, test it - one new thing at a time

Notebook

Step 0

Step 1

Step 2 (Do not follow!!)

Step 3

Step 4

Step 5

Step 6

Step 7

Step 8

Step 9

Code

Here’s the code on Github

Time

10.75 hours figuring out & learning
3 hours coding
1 hour documenting