random(int32_t min, int32_t max) unexpected results

[tshcherban]

Is there a bug in random generate function (overload with min/max parameters)?

To Reproduce

SX1262 radio = new Module(NSS, DIO1, NRST, BUSY);
.
.
.
PhysicalLayer *pl = &radio;
for (int i = 0; i < 20; ++i)
{
  int32_t pause = pl->random(2500, 6500);
  Serial.println(String(pause));
}

Actual result

-783
2900
5732
-545
2526
4675
5544
4978
2538
5929
2069
4129
3148
4257
-3
2002
6389
6400
-942
830

Expected behavior
Should return something between specified parameters.

Additional info (please complete):

• MCU: Atmega328, ESP32
• Wireless module SX1262
• Arduino IDE version 1.8.13
• Library version 4.4.2

[tshcherban]

If i understood correctly, randNum after raw initialization can contain ANY number in range of int32_t.
I'm not strong in math but that line looks strange:

It does clipping the number from top, but not from bottom. Maybe use map or its equivalent formula here?

[jgromes]

The min/max implementation is the same as in Arduino AVR core to achieve the exact same behavior as Arduino random() function. There was however a bug in negative number handling.

Fixed in last commit, thanks for reporting!