Add 'pin' argument to read(), remove listento()

Instead of having separate listento and read functions, just
pass the pin to read directly.

Signed-off-by: Keith Packard <keithp@keithp.com>

doc/snek.adoc

@@ -686,15 +686,15 @@ Digital pin 13:(((talkto)))(((on)))
 
 [source,subs="verbatim,quotes"]
 ----
-> *talkto(13)*
+> *talkto(D13)*
 > *on()*
 ----
 
 Let's get a bit fancier and blink it:(((time.sleep)))
 
 [source,subs="verbatim,quotes"]
 ----
-> *talkto(13)*
+> *talkto(D13)*
 > *while True:*
 +     *onfor(.5)*
 +     *time.sleep(.5)*
@@ -703,14 +703,13 @@ Let's get a bit fancier and blink it:(((time.sleep)))
 ==== Hooking up a digital input
 
 Find a bit of wire to connect from Digital pin 1 to GND and let's
-control the LED with this primitive switch:(((listento)))(((off)))
+control the LED with this primitive switch:(((read)))(((off)))
 
 [source,subs="verbatim,quotes"]
 ----
-> *listento(1)*
-> *talkto(13)*
+> *talkto(D13)*
 > *while True:*
-+     *if read():*
++     *if read(D1):*
 +         *on()*
 +     *else:*
 +         *off()*
@@ -726,16 +725,12 @@ Analog pin 0 and make the LED track the sensor:(((read)))(((onfor)))
 
 [source,subs="verbatim,quotes"]
 ----
-> *listento(14)*
-> *talkto(13)*
+> *talkto(D13)*
 > *while True:*
-+     *onfor(1-read())*
-+     *time.sleep(1-read())*
++     *onfor(1-read(A0))*
++     *time.sleep(1-read(A0))*
 ----
 
-Note that the Arduino analog pin A0 is called pin 14 in snek (A1 is
-pin 15, etc).
-
 ==== Controlling motors
 
 So far, we've only talked about using one pin at a time. Arduino motor
@@ -1922,9 +1917,6 @@ Set the current output pins. If _pin_ is a number, this sets both the
 Power and Direction pins. If _pin_ is a List or Tuple, then the first
 element sets the Power pin and the second sets the Direction pin.(((talkto)))
 
-=== `listento(` _pin_ `)`
-Sets the current input pin to _pin_.(((listento)))
-
 === `setpower(` _power_ `)`
 
 Sets the power level on the current Power pin to _power_. If the Power
@@ -1954,11 +1946,11 @@ Turns the current Power pin *off*.(((off)))
 Turns the current Power pin *on*, delays for _seconds_ and then
 turns the current Power pin *off*.(((onfor)))
 
-=== `read()`
+=== `read(` _pin_ `)`
 
-Returns the value of the current Input pin. If this is an analog pin,
-then `read()` returns a value from `0 to 1` (inclusive). If this a digital pin, then
-`read()` returns either `0` or `1`.(((read)))
+Returns the value of _pin_. If this is an analog pin, then `read`
+returns a value from `0 to 1` (inclusive). If this a digital pin, then
+`read` returns either `0` or `1`.(((read)))
 
 === `stopall()`
 

examples/snek-car.py

@@ -92,16 +92,14 @@ def stop():
 # Move forward until we approach something
 def go_forw():
     forw()
-    listento(pf)
-    while read() < .25:
+    while read(pf) < .25:
         pass
     stop()
 
 # Move backwards until we approach something
 def go_back():
     back()
-    listento(pr)
-    while read() < .25:
+    while read(pr) < .25:
         pass
     stop()
 

examples/track-light.py

@@ -17,11 +17,10 @@
 
 def track():
     talkto(led)
-    listento(dial)
     setpower(0)
     on()
     while True:
-        p = read()
+        p = read(dial)
         if p == 1:
             break
         setpower(p)

samd21/snek-altos.builtin

@@ -14,14 +14,13 @@
 time.sleep, 1
 time.monotonic, 0
 talkto, 1
-listento, 1
 setpower, 1
 setleft, 0
 setright, 0
 onfor, 1
 on, 0
 off, 0
-read, 0
+read, 1
 stopall, 0
 eeprom.write, 0
 eeprom.show, -1

samd21/snek-gpio.c

@@ -18,7 +18,6 @@
 
 static uint8_t	power_pin;
 static uint8_t	dir_pin;
-static uint8_t	input_pin;
 static uint16_t	power[AO_SNEK_NUM_PIN];
 static uint32_t	on_pins;
 
@@ -245,18 +244,6 @@ snek_builtin_talkto(snek_poly_t a)
 	return SNEK_NULL;
 }
 
-snek_poly_t
-snek_builtin_listento(snek_poly_t a)
-{
-	uint8_t p = snek_poly_get_pin(a);
-	if (!snek_abort) {
-		set_dir(p, 0);
-		input_pin = p;
-	}
-	return SNEK_NULL;
-}
-
-
 snek_poly_t
 snek_builtin_setpower(snek_poly_t a)
 {
@@ -307,13 +294,18 @@ snek_builtin_onfor(snek_poly_t a)
 #define analog_reference 1
 
 snek_poly_t
-snek_builtin_read(void)
+snek_builtin_read(snek_poly_t a)
 {
-	if (has_adc(input_pin)) {
-		float value = ao_snek_port_get_analog(input_pin) / (float) AO_ADC_MAX;
+	uint8_t p = snek_poly_get_pin(a);
+	if (snek_abort)
+		return SNEK_NULL;
+	set_dir(p, 0);
+
+	if (has_adc(p)) {
+		float value = ao_snek_port_get_analog(p) / (float) AO_ADC_MAX;
 		return snek_float_to_poly(value);
 	} else {
-		return snek_bool_to_poly(ao_snek_port_get(input_pin));
+		return snek_bool_to_poly(ao_snek_port_get(p));
 	}
 }
 

snek-duino/snek-duino.builtin

@@ -14,14 +14,13 @@
 time.sleep, 1
 time.monotonic, 0
 talkto, 1
-listento, 1
 setpower, 1
 setleft, 0
 setright, 0
 onfor, 1
 on, 0
 off, 0
-read, 0
+read, 1
 stopall, 0
 eeprom.write, 0
 eeprom.show, -1

snek-duino/snek-duino.c

@@ -264,17 +264,6 @@ snek_builtin_talkto(snek_poly_t a)
 	return SNEK_NULL;
 }
 
-snek_poly_t
-snek_builtin_listento(snek_poly_t a)
-{
-	uint8_t p = snek_poly_get_pin(a);
-	if (!snek_abort) {
-		set_dir(p, 0);
-		input_pin = p;
-	}
-	return SNEK_NULL;
-}
-
 static bool
 is_on(uint8_t pin)
 {
@@ -366,11 +355,16 @@ snek_builtin_onfor(snek_poly_t a)
 #define analog_reference 1
 
 snek_poly_t
-snek_builtin_read(void)
+snek_builtin_read(snek_poly_t a)
 {
-	if (input_pin >= 14) {
-		uint8_t pin = input_pin - 14;
-		ADMUX = (analog_reference << 6) | (pin & 7);
+	uint8_t p = snek_poly_get_pin(a);
+	if (snek_abort)
+		return SNEK_NULL;
+	set_dir(p, 0);
+
+	if (p >= 14) {
+		uint8_t pin = p - 14;
+		ADMUX = (analog_reference << REFS0) | (pin & 7);
 		ADCSRA |= (1 << ADSC);
 		while (ADCSRA & (1 << ADSC))
 			;
@@ -380,7 +374,7 @@ snek_builtin_read(void)
 
 		return snek_float_to_poly(value);
 	} else {
-		return snek_bool_to_poly(*pin_reg(input_pin) & bit(input_pin));
+		return snek_bool_to_poly(*pin_reg(p) & bit(p));
 	}
 }