In a sketch I will be entering a large amount of sample data pairs consisting of an unsigned long value and a byte value (a checksum of sorts). Of course I could make them both longs, or I could enter all the longs in one array and all the bytes in another. But the data would be easier to enter, a…

Examples: Array of Structures in C | GeeksforGeeks

On other than an 8 bit processor an array of structures would be equivalent in size to an array of 2 longs due to structure alignment. Unless you use __attribute__((packed)) on the struct. In which case see [image] Why I hate __attribute__((packed)) General Guidance Once …

so to answer the question clearly, NO you can't. All the items in an array share the same type (which can be a compound type like a struct or class and so you could pack different data).

Thanks very much for the responses. I'm afraid my C++ knowledge is pretty limited. I never quite got to structs. No time like the present, I guess. But I did once place an array into flash using PROGMEM. Can I do that with a two-dimensional array of longs, and then read one part back into ram a…

Which Arduino are you targeting?

I'd like it to work on a basic Uno or Nano (328P). So the issue is finding a way to enter data in a reasonable manner - in pairs - without ram being a limit on how many samples I can use. If the PROGMEN method will let me do a two-dimensional long array in flash, then I can begin the program trans…

Example of using an array of structs: struct { int number; char character; } myArray[5] = { {1, 'A'}, {2, 'B'}, {3, 'C'}, {4, 'D'}, {5, 'E'}}; void setup() { Serial.begin(115200); for (int i = 0; i < 5; i++) { Serial.print(myArray[i].number); Serial.print(" translates to "); …

[image] ShermanP: The problem is ram filling up. If you want to write to the array while the program is running, PROGMEM is not useful, as the array contents are fixed at compile time. You might take a look at the Adafruit Feather boards. They are really nice and most have quite a bit more R…

I will take a look at the struct option. But I did try an example of defining the array in PROGMEN, and then reading it back into ram, but with the second long field brought in as bytes. const unsigned long Key[][2] PROGMEM = { {14256, 95}, {8395, 19}, {88493, 4}, {9586, 42}, {33333, 24}…

Can a two-dimensional array have a different data type for each dimension?

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xfpd May 23, 2025, 1:18am 12

Put whatever data you want in a linear array. Write a translator to decide what the data is and write "dimensional" math to extract the correct element from the correct dimension.

Here is how I made fake 10-dimension arrays... using a single dimension array... and why I can not think in terms of struct or arrays of arrays... in PROGMEM.

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Can a two-dimensional array have a different data type for each dimension?

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