LEDx.toggle()?

[espruino-discuss3]

Posted at 2017-01-19 by Ollie

There's a bit of code required to toggle an LED. The LEDx.set/reset functions help (which I'd not used before getting a Puck - were they available before?), but it struck me that a LEDx.toggle() abstraction would be really useful, in general, and especially when sending commands over BLE/between Pucks given the buffer limit.

Is this feasible?

[espruino-discuss3]

Posted at 2017-01-20 by @allObjects

What about having this global function uploaded? It will toggle any pin:

function toggle(pin) { pin.write(pin, !pin.read(); }

To be on the safe side - NOT make an input pin an output pin - use this code:

function toggle(pin) {
  if (pin.getMode().indexOf("output") > -1) {
    pin.write(pin, !pin.read();
} }

...and prototype-based-object-oriented, upload this expression, which will give you the .toggle():

Pin.prototype.toggle = function(){ 
    if (pin.getMode().indexOf("output") > -1) {
      pin.write(pin, !pin.read();
  } }

---

Posted at 2017-01-20 by @gfwilliams

LEDx.set/reset functions help - were they available before?

Yes, pretty much right since the start :)

I've resisted putting toggle in so far because it's only use is really for LEDs. People think it's just write(!read()) but in reality it's a bit more nuanced than that because read reads the input register, which is actually different to the current output state (think what happens in opendrain mode).

What @allObjects is suggesting (this.write(pin, !this.read();) should work ok for LEDs though. It should be pretty easy to upload that beforehand?

---

Posted at 2017-01-20 by @gfwilliams

I just added a .toggle function so it'll be in 1v92 - it's one of those things that's a lot easier to do now than it was when Espruino was first made.

It's worth noting that it it doesn't work on the ESP8266 port, because on that the internal jshPinGetState function doesn't actually inspect the physical peripheral to find out what state the output register is in.

---

Posted at 2017-01-20 by Ollie

Excellent, thank you! I could see that uploading a bit of code would be easy enough, but to have this available out the box is much better!

---

Posted at 2017-01-20 by Wilberforce

@gfwilliams. For the esp the pin state is saved in array - so that could be used for the toggle.

https://github.com/espruino/Espruino/blob/master/targets/esp8266/jshardware.c#L420

This might just work out of box:

JshPinState jshPinGetState(Pin pin) {
  //os_printf("> ESP8266: jshPinGetState %d\n", pin);
  return g_pinState[pin];
}

@jumjum

Once this is up on github, we can take a look and also add it to the esp32 port - or a least document as a todo.

---

Posted at 2017-01-23 by @gfwilliams

You might want to add:

JshPinState jshPinGetState(Pin pin) {
  if (GPIO_REG_READ(GPIO_OUT_W1TS_ADDRESS, 1<<pin))
    return g_pinState[pin]|JSHPINSTATE_PIN_IS_ON;
  return g_pinState[pin];
}

I think that'll do it - just depends if that register can be read or not.

Basically jshPinGetState needs to be able to tell if the pin is meant to be on.

It makes stuff like digitalWrite(LED1,1);save() work - which wouldn't have on ESP8266 before

---

Posted at 2017-01-24 by @MaBecker

Did some tests

GPIO_REG_READ(GPIO_OUT_ADDRESS)>>pin)&1

can be used for this, created PR #1034

---

Posted at 2017-01-24 by @gfwilliams

merged. So 1v92 should have this in

---

Posted at 2017-01-26 by Wilberforce

@gfwilliams

JshPinState jshPinGetState(Pin pin) {
  if (GPIO_REG_READ(GPIO_OUT_W1TS_ADDRESS, 1<<pin))
    return g_pinState[pin]|JSHPINSTATE_PIN_IS_ON;
  return g_pinState[pin];
}

If the hardware is getting read - is there any point in using the g_pinState[pin] array?

And I don't follow why the OR is used?

Thanks

---

Posted at 2017-01-26 by @MaBecker

Hi @wilberforce,

JshPinGetState() now returns pinState "or" JSHPINSTATE_PIN_IS_ON if pin is high.

jswrap_pin_toggle() can use JshPinState() to set bool on =

---

Posted at 2017-01-26 by Wilberforce

Yes - I don't understand why the OR is used, if the hardware is getting read - then that would be sufficient I would have thought?

---

Posted at 2017-01-27 by @gfwilliams

edit: didn't see the previous posts.

jshPinGetState does a lot more than just return whether the pin is on or off, it does 'pullup'/'input'/'output'/etc - it's what is used for getPinMode - so you do need the array.