qtvcp -docs: update libraries/code snippets with core.py changes

function names changes, add an example of pin reading writing

Author: c-morley

docs/src/gui/qtvcp-code-snippets.adoc

@@ -264,6 +264,9 @@ from qtvcp.core import Qhal
 ----
 
 This is to allow access to *QtVCP's HAL component*.
+<<cha:qtvcp:Qhal,For more info: Qhal>> +
+Qhal's newPin function returns a QPin object.
+<<cha:qtvcp:QPin,For more info: QPin>>
 
 .Instantiate `Qhal` in the `INSTANTIATE LIBRARY SECTION`
 [source,python]
@@ -272,7 +275,7 @@ QHAL = Qhal()
 ----
 
 .Add a function that gets called when the pin state changes
-Under the `initialised__` function, make sure there is an entry similar to this:
+Under the `initialized__` function, make sure there is an entry similar to this:
 
 [source,python]
 ----
@@ -284,8 +287,8 @@ Under the `initialised__` function, make sure there is an entry similar to this:
 # the widgets are instantiated.
 # the HAL pins are built but HAL is not set ready
 def initialized__(self):
-    self.pin_cycle_start_in = QHAL.newpin('cycle-start-in',QHAL.HAL_BIT, QHAL.HAL_IN)
-    self.pin_cycle_start_in.value_changed.connect(lambda s: self.cycleStart(s))
+    self.pin_cycle_start_in = QHAL.newPin('cycle-start-in',QHAL.HAL_BIT, QHAL.HAL_IN)
+    self.pin_cycle_start_in.pinValueChanged.connect(lambda o,s: self.cycleStart(s))
 ----
 
 .Define the function called by pin state change in the `GENERAL FUNCTIONS SECTION`
@@ -313,6 +316,35 @@ In this way the cycle start button works differently depending on what tab is sh
 
 This is simplified - _checking state and error trapping might be helpful_.
 
+== Read/Write System HAL Pins Directly
+Sometimes you need to read a system pin and creating a HAL pin and connecting to it,
+is more work then required. You can read it directly without connecting to it.
+
+Here is how to read a pin, parameter, or signal:
+
+[source,python]
+----
+self.h.hal.get_value('spindle.0.at-speed')
+
+# or use the Qhal library like this:
+QHAL.getValue('spindle.0.at-speed')
+----
+
+Here is how to write to an unconnected pin or a non driven signal:
+
+[source,python]
+----
+self.h.hal.set_p('componentName.pinName','10')
+self.h.hal.set_s('componentName.signalName','10')
+
+# or use the Qhal library like this:
+QHAL.setPin('componentName.pinName', '10')
+QHAL.setSignal('componentName.signalName', '10')
+----
+
+Using 'self.h.hal' or 'QHAL.hal' allows access to the HAL python module functions:
+ <<cha:python-hal-interface, Python HAL Interface>>
+
 == Add A Special Max Velocity Slider Based On Percent
 
 Some times you want to *build a widget to do something not built in*.

docs/src/gui/qtvcp-libraries.adoc

@@ -383,19 +383,23 @@ ACTION.TOUCHPLATE_TOUCHOFF(search_vel, probe_vel, max_probe,
        z_offset, retract_distance, z_safe_travel, rtn_method=None, error_rtn = None)
 ----
 
+[[cha:qtvcp:Qhal]]
+
 == Qhal
 
-A library for HAL component interactions.
+A library for HAL component/system interactions.
 
 === Attributes
 
 These are the functions that can be called on the Qhal object:
 
-*`newpin(name, pin type constant, pin direction constant)`*:: returns a new QPin object
-*`getpin(name)`*:: returns an existing named QPin object
-*`getvalue(name)`*:: returns the named pin's value, use the full component/pin name.
-*`setp(name,value)`*:: sets the named pin's value, use the full component/pin name.
-*`makeUniqueName(name)`*:: returns an unique HAL pin name string by adding '-x' (a number) to the base name
+*`setUpdateRate(cyclerate)`*:: Set cycle rate in ms
+*`newPin(name, pin type constant, pin direction constant)`*:: returns a new QPin object
+*`getPinObject(name)`*:: returns an existing named QPin object
+*`getValue(name)`*:: returns the named pin, signal, or parameter's value, use the full component.pin name.
+*`setPin(name,value)`*:: sets the named pin's value, use the full component.pin name.
+*`setSignal(name,value)`*:: sets the named signal's value, use the full component.pin name.
+*`makeUniqueName(name)`*:: returns an unique HAL pin name string by adding '-x' (a number) to the given pin name string
 *`exit()`*:: kills the component
 
 === Constants
@@ -418,13 +422,14 @@ Available object references:
 * *comp* the component object
 * *hal* the hal library object
 
+[[cha:qtvcp:QPin]]
 == QPin
 A wrapper class around HAL pins
 
 === Signals
 There are 3 Qt signals that the QPin pin can be connect to:
 
-* *value_changed* will call a named function with an argument of the current value
+* *value_changed* will call a named function with an argument of the current value (depreciated)
 * *pinValueChanged* will call a named function with arguments of the pin object and the current value
 * *isDrivenChanged* will call a named function with arguments of the pin object and current state when
  the pin is (un)connected to a driving pin