This content originally appeared on DEV Community and was authored by asim-builds
Ever since I have build hobby projects using Arduino, I have been fascinated by how embedded systems process real-world data in real time. Since I was interested in embedded systems, I picked up C and started to read theory. But learning by reading was just boring to me and most of the concepts went straight to my head. So I decided to do something practical: Do a mini project that I can talk about. So I decided to create a "sensor simulator". Here is my journey of the mini project, what I learned at each step, what was hard, and where I am taking it next!!
Phase 1: Basic Dumb Simulator
The first step was to simulate reading sensor data from a CSV file.
So I did the following:
- Read sensor values from a CSV file.
- Scaled the values to reflect real-world readings.
- Stored the values in an array.
- Calculated basic stats: average, min, max, and sum.
- Printed alerts if any values crossed defined thresholds.
Key Learnings:
- Basic file handling in C (using fopen, fscanf, etc.).
- Using arrays and practicing both indexing and pointer arithmetic.
- Implementing structs to represent sensor data and thresholds.
The hardest part here was switching from indexing (arr[i]) to pure pointer arithmetic (*(arr + i)). At first, it felt unintuitive, but after forcing myself to do it, I got a much better understanding of how memory works in C.
Phase 2: Real-Time Data Processing
Next, I wanted to make the simulator feel "alive" by processing data in real time. Here is what I did:
- Implemented a loop that reads values every second (using sleep).
- Continuously updated alerts and recalculated stats.
- Allowed the user to change threshold values at runtime.
Key Learnings:
- Simulating real-time behavior taught me about timing, delays, and how to keep a loop responsive.
- Using structs to pass around stats instead of using many global variables.
- Starting to modularize the code into functions and (later) separate files.
The biggest challenge here was avoiding to write everything in the main function. I had to force myself to split code into smaller, manageable chunks.
Phase 3: Control Logic & Event Simulation
The final phase was about making the simulator act like a simple control system. Here is what I did:
- Added control outputs based on sensor data (e.g., turn on a "fan", "heater", or an "LED" — printed to console for now).
- Added a switch-case menu for the user to choose between simulation, stats, or updating thresholds.
*What's next? *
While I was working through pointers, index arithmetic, and splitting code into multiple functions in C, I couldn’t help but think about how much easier all of this felt in Python.
When I was first learning Python, I thought lists, dictionaries, and their methods were hard. But now, I realize I hadn’t even scratched the surface.
Example:
In Python, to add an element to an existing list, I can simply do this:
my_list.append(42)
In C, I have to manually manage memory and handle resizing:
if (size == capacity) {
capacity *= 2;
arr = realloc(arr, capacity * sizeof(int));
}
arr[size++] = 42;
Working in C made me appreciate how many things Python quietly takes care of for us — dynamic arrays (lists), memory management, high-level abstractions.
This also led me to question something important:
Do I actually love embedded systems and low-level coding, or was it just the excitement of hobby projects (where I didn’t have to think too deeply about memory and pointers) that I enjoyed?
I think it’s good to ask this question now rather than blindly keep "learning C" just because it sounds cool or "hardcore."
So, my plan is to go one step further: I’ll dive head first into programming actual hardware (like microcontrollers), and see if I truly enjoy embedded systems when I get to interact with real-world components.
This isn’t just about syntax anymore — it’s about finding out what kind of work excites me most, what kind of bugs I can tolerate, and what challenges keep me coming back instead of burning me out.
This content originally appeared on DEV Community and was authored by asim-builds
asim-builds | Sciencx (2025-07-14T13:45:12+00:00) Building a Dumb Sensor Simulator in C (That Taught Me How I Took Python For Granted). Retrieved from https://www.scien.cx/2025/07/14/building-a-dumb-sensor-simulator-in-c-that-taught-me-how-i-took-python-for-granted/
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