The four saved sketches give me four ways to look at the meter. The scanner searches for replies, the raw sampler prints counts and input volts, the RMS program works through separate collections, and the full meter combines stored readings into more quantities. I like the fact that their jobs are different. A larger program does not make every smaller question disappear; it puts several answers together and depends on their meanings staying clear.
The scanner's question is whether a device replies at an address on the bus. A response gives me a useful place to begin. It doesn't mean a sensor is calibrated or that the samples will be taken at the right time. Keeping that limit clear makes the result more useful. I can stop asking it to prove things it wasn't written to check and use the next small sketch for the next question.
The raw-reading sketch moves one step further. Now there is a value from an input to examine. Before I turn it into a voltage, current or power label, I can ask which channel it came from and what range or setting was used. The output might look less impressive than a finished display, but it keeps the number closer to the part of the system that produced it. There are fewer transformations to untangle.
The RMS sketch then gives me a calculation to inspect. I can follow offset removal, squaring, accumulation, averaging and the square root without also trying to understand every displayed quantity. A small calculation can help check my explanation of the loop. That’s different from using a calculation as evidence that the hardware measures accurately. One checks my reasoning about an operation; the other would need an actual measurement comparison.
The full program combines those stages and adds relationships between them. A problem there might come from communication, sensing, timing, scaling or the later calculation. That’s why the smaller sketches aren't just early files to put away once the bigger one exists. They give me ways to return to a particular question without changing everything around it. I can understand a result better when I know which question the test actually asked.
I broke the troubleshooting down into smaller checks. In this case, the ADC stops responding. That would send me towards communication and connections before a power calculation. In this case, it responds but the raw value seems wrong. Then the input and settings become more relevant. In this case, individual readings look reasonable but a combined quantity is confusing. The relationship between the channels and the calculation needs attention. These are examples of how to separate questions, not new faults I've observed today.
The acquisition changes between files too. The RMS sketch uses a 100 ms voltage collection followed by a 100 ms current collection with fixed offsets. The final meter fills two 400-entry arrays through sequential channel calls and estimates the centres from that collection. That difference is worth keeping beside any comparison of outputs. I can follow the same broad idea, measurement from samples, while noticing that the programs do not gather and centre those samples in identical ways. Each file makes one part of the route easier to inspect.
The order matters because changing a later equation cannot repair every earlier problem. If I alter calibration while the connection itself is unreliable, a new output may only create a new guess. If I change the display while the value underneath it is unclear, I have made the uncertainty look different. Starting smaller is a way of preserving the meaning of each change, rather than collecting several changes and hoping their effects cancel out.
I'm also looking for the assumptions inside each sketch. A delay that makes serial output readable might be fine for checking a channel, but unsuitable for following a waveform. A fixed offset might make a demonstration easy to understand, while the real offset still needs checking. A test file's simplicity doesn't remove its conditions. It just makes them easier to find if I remember to look for them.
Version notes become important here. I need to know which sketch goes with which board arrangement and settings. A familiar filename doesn't guarantee the contents match the version I have in mind. If a small test and the final program use different constants, the difference deserves a note. Otherwise I could compare their output and invent an explanation for a change that was already written into the files.
This gives me a more useful mentor discussion too. I can show which smaller question I have followed and where the result stops helping. We can stay with that stage instead of moving immediately to every feature of the meter. An explanation can help unpack a function, but I still have to decide whether it belongs to this particular test and check the code that is actually open.
What I want from this review is a map I can use later: communication first, then the input value, then the calculation and finally the combined output. It isn't a compulsory order for every problem. A clear symptom might point somewhere else. But when I’m confused about several things at once, the map gives me a way to make one question small enough to answer.
The small sketches form a map of questions rather than a pile of leftovers. Communication, input values, calculation and combined output each have a place I can return to and explain.