analogWrite() duplicates output on additional pin use - WiFi 2v04

Sat 2019.11.23

Needs to be verified with an oscilloscope

Repeatable

Found this example that suggests two pins of the same prefix should work

http://www.espruino.com/LM393#line=9,10

http://www.espruino.com/Reference#l__global_analogWrite
Doesn't indicate that only one instance of analogWrite() may exist

I originally thought this to be the number suffix when using setWatch(),

http://www.espruino.com/Reference#l__global_setWatch
'Note: The STM32 chip (used in the Espruino Board and Pico) cannot watch two pins with the same number - eg A0 and B0.'

but after eliminating unnecessary code, found to be repeatable on other pins also.

// 0.001 sec or 1msec or 100Hz
// A0 PWM out - 10% duty cycle hi

function a0() {
  analogWrite( A0, 0.1, { freq : 100 } );
}

// 0.1 sec or 100msec or 1Hz
// A5 PWM out - 10% duty cycle hi
function a5() {
  analogWrite( A5, 0.1, { freq : 1 } );
}

Run a0() - See Orn D3 output

reset(1)

Run a5() - See Pur D7 output

reset(1)

Run a0()
Run a5() - See duplicated output - should be different!!

A0 Orn D3 is being assigned the last defined analogWrite() A5

Also tried with combinations of A(n) and B(n) pins - repeatable there also.

The comments at

https://github.com/espruino/Espruino/blob/master/src/jswrap_io.c#L167

imply multiple pins may be used.

{
  "VERSION": "2v04",
  "GIT_COMMIT": "3956264e",
  "BOARD": "ESPRUINOWIFI",
  "FLASH": 524288, "RAM": 131072,

Low priority (for me anyway) solution required as I am getting by with

http://www.espruino.com/Reference#l__global_digitalPulse

---

3 Attachments

• 
• 
•