hi there I have a float number, say 6.38. I want to show that on a screen with one floating point. so I used the code below char str_tmp[5]; sprintf(str_tmp,"%2.1f",6.38); I expect to get 6.3 but looks like the code line above, rounds up 6.38 to 6.4 and then shows it with one floating point... …

that's not really what I want... any other suggestions?

Sorry missed the point One idea is x10, truncate and divide by 10 to get 1 decimal digit (give or take the poor precision of floats)

For many of the Arduino processors, floats are disabled in sprintf. Another way is to convert the float number to a string with the dtostrf() function then use the %s placeholder to put it into your snprintf() function. Note that snprintf() is safer to use. float floatNumber = 3.141592; void se…

Your sketch shows: the float number is 3.141592 OP wants: 3.1

[image] ALAA72: I have a float number, say 6.38. I want to show that on a screen with one floating point. Many arduino print functions similar to Serial.print() has the second parameter, controlling the number of floating point float f = 6.38; Serial.print(f,1); output the 6.4 [image] A…

[image] groundFungus: I saw that the OP was using sprintf (and its in the title) so assumed that that is what they wanted to do. If all they really want is to display 6.3 from 6.38 they could just: Serial.println(6.38, 1); That command shows: 6.4 and not 6.3! Output: 6.4

one approach 123.456 #define frac(x) (int(1000*(x - int(x)))) char s [80]; // ----------------------------------------------------------------------------- void setup () { Serial.begin (9600); float x = 123.456; sprintf (s, " %6d.%03d", int(x), frac(x)); Serial.printl…

Your output is: 123.456 But, OP wants: 123.4

[ [image] GolamMostafa: But, OP wants: 123.4 quote="gcjr, post:12, topic:1013193"] #define frac(x) (int(1000*(x - int(x)))) [/quote] shouldn't he be able to figure out changing 1000 to 10?

Sprintf() a float number

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J-M-L July 17, 2022, 4:45am 2

Try truncating the value

https://m.cplusplus.com/reference/cmath/trunc/

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Sprintf() a float number

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