Matrix user forums

I did a simple frequency counter example here: https://www.matrixtsl.com/mmforums/viewtopic.php?f=26&t=20970&hilit=Frequency+counter that used two interrupts to count frequency... I used a rtc chip to generate the 1s interrupt rather than an inbuilt timer. I have an anemometer here that came from a ...

Hi Monie,

You don't seem to enable your timer interrupt in the code sample...

Martin

Try:

When you print out the read back characters you are 'printing' or displaying them as numbers (they are the ASCII representation of the desired string). Post your code and we'll be able to change if needed...

Martin

Try this.

[url]viewtopic.php?f=78&t=21435[\url]

I had to do the registry reset too...

Martin

I used https://www.scadacore.com/tools/program ... converter/ to check the required layout.

Martin

I had similar problem after a recent windows update:

viewtopic.php?f=78&t=21435 sorted me out.... (I needed to do the RegEdit fix - but try the re-install first.)

Martin

So the 4 bytes represent a 32 bit (4x8) floating point number.... Adding them doesn't do what you want - they are just a representation of the underlying 32 bits of data... See https://en.wikipedia.org/wiki/IEEE_754 if you want a summary of the full low down (and I suspect IEEE754 is a huge document...

... The computer memory is an 'array' of 8 bit 'cells' with an address for each (so for an Arduino - the address could be 0..2047 for it 2048 byte RAM) A 'variable' in a program is actually the address of one or more bytes in memory (so for a float (32 bit) it would point to 4 bytes somewhere in the...

More usefully as a macro.... Martin

This works (on an Arduino at least) float.JPG Uses an array of 4 bytes 'n and a float f and a string t (meaningful names!?) The C code puts the hex given into a float in reverse order (so f[3] = h[0]) and converts from hex to a float using a union... Just output converted value to UART as a test... ...

Thanks Daniel,

That fixed things.. Any idea what went wrong though?

Martin

Thanks, will give it a whirl this evening...

- sending the message as a hex string seems strange? But - it is easy to do - StrToHex.fcfx Has 3 demonstrations 1) convert a string to hex a character at a time (output to UART) 2) Convert a string to HEX (so 'ABC' -> '414243') again output to UART. Note that here the output string MUST be large en...

It's not too bad to do: Assuming you want to convert everything to a hex string? For example: 'A' = 65 =0x41 (or 41?) So if .c = a character then add to the sms (0x if using) and HexDigit(.c >>4) and HexDigit(.c & 0x0f) Where HexDigit adds '0' to value if it is 0..9 and 'A' - 10 to value otherwise.....

- nope, still bombs.

Tried running as admin too...

No error message.

& something aint right...

Open a project (after fresh install) and CircularBuffer has no properties or macros.

Run updates (~CAL_UART_String only) and restart - and back to closing on start ((program loads then FC dies)

Martin

And finally back...

Uninstalled and re-installed and still closing. Opened a project and closed apart from 'start' page and 'properties'.

Opened a project from start page and back in business - no idea what went wrong?

Martin

No problem. Let me know if you have any questions...

Latest windows update went through last night... Now Flowcode v8 opens and then closes after splash screen and home page opens (briefly) Only shows as a background process in Task Manager. Strangely - opening some projects (by clicking on the project in start menu) - results in the Property Window b...

I tried a small (16) byte lookup and depending on the loop type used it was either slightly faster or slightly slower than the rotate and count used above. Using a 'for' loop was much quicker than a while or until at least on an Arduino mega2560... Took approx 90s for 1million random number bit coun...

Ok A simple bit count macro - and a test 'main' that just counts the bits in random numbers and spits the result to UART (with a 1s delay to give you a chance to check the result :-) ) Note that I'm counting 16 bits (of a WORD) here - you can modify if needed to count 12 or ignore bit 0 as required....

Quickest is a lookup table - but depends on how much free memory you have.... (2 x 8 bit look ups?) (The value retrieved from table can even be byte with parity bit set - rather than count of 1s) Shift and add (count = count + (n & 1); n = n >> 1 for no. of bits)? Or with a bit of fancy math: - see ...

There is an excellent description of usage on the Adafruitv site https://learn.adafruit.com/thermistor/overview
They describe the range of the thermistor as going to 125C but if you have a device capable of more then the techniques used the should be applicable.

Martin

Does that turn day into night

No - sorry - I might have to google what one of those does?

Martin