typed interface for the GPIO pins on RPI 3

_oasis

@@ -9,7 +9,7 @@ Plugins:     META (0.4), DevFiles (0.4)
 Library "WiringPi"
   Path:       src/
   BuildTools: ocamlbuild
-  Modules:    WiringPi
+  Modules:    WiringPi, Gpio3
   CSources:   WiringPi_stubs.c
   CCLib:      -lwiringPi
 

src/Gpio3.ml

@@ -0,0 +1,95 @@
+(** Typed interface for WiritngPi.
+ Missing:
+ - modes PWM_OUTPUT and GPIO_GLOCK
+ - pwm_write
+ - digital_write_byte
+ - analog_read
+ - analog_write
+ - delay, delay_microseconds (?)
+ *)
+open WiringPi
+
+let setup () = ignore (setup_gpio ())
+
+type pin =
+ (*  3V3  |  5V   *)
+    GPIO2 | (* 5V *)
+    GPIO3 | (* GND *)
+    GPIO4 | GPIO14
+(* GND *) | GPIO15 |
+   GPIO17 | GPIO18 |
+   GPIO27 | (* GND *)
+   GPIO22 | GPIO23
+(* 3V3 *) | GPIO24 |
+   GPIO10 | (* GND *)
+    GPIO9 | GPIO25 |
+   GPIO11 | GPIO8 
+(* GND *) | GPIO7  |
+    GPIO0 | GPIO1  |
+    GPIO5 | (* GND *)
+    GPIO6 | GPIO12 |
+   GPIO13 | (* GND *)
+   GPIO19 | GPIO16 |
+   GPIO26 | GPIO20
+
+let int_of_pin = function
+  | GPIO2 -> 2
+  | GPIO3 -> 3
+  | GPIO4 -> 4
+  | GPIO14 -> 14
+  | GPIO15 -> 15
+  | GPIO17 -> 17
+  | GPIO18 -> 18
+  | GPIO27 -> 27
+  | GPIO22 -> 22
+  | GPIO23 -> 23
+  | GPIO24 -> 24
+  | GPIO10 -> 10
+  | GPIO9 -> 9
+  | GPIO25 -> 25
+  | GPIO11 -> 11
+  | GPIO8 -> 8
+  | GPIO7 -> 7
+  | GPIO0 -> 0
+  | GPIO1 -> 1
+  | GPIO5 -> 5
+  | GPIO6 -> 6
+  | GPIO12 -> 12
+  | GPIO13 -> 13
+  | GPIO19 -> 19
+  | GPIO16 -> 16
+  | GPIO26 -> 26
+  | GPIO20 -> 20
+
+(* What is not supported: PWM_OUTPUT and GPIO_GLOCK *)
+type mode = IN | OUT
+
+(** [pin_mode] sets the mode of the pin to either input or output
+   (other modes not supported at this moment). *)
+let pin_mode (p : pin) (m : mode) =
+  match m with
+  | IN -> WiringPi.pin_mode (int_of_pin p) 0
+  | OUT -> WiringPi.pin_mode (int_of_pin p) 1
+
+type pin_updn = UP | DOWN | OFF
+
+(** [pull_up_dn_control] sets the pull-up or pull-down resistor mode on
+   the given pin, which should be set as an input. *)
+let pull_up_dn_control (p : pin) = function
+  | UP -> WiringPi.pull_up_dn_control (int_of_pin p) 2
+  | DOWN -> WiringPi.pull_up_dn_control (int_of_pin p) 1
+  | OFF -> WiringPi.pull_up_dn_control (int_of_pin p) 0
+
+type pin_value = LOW | HIGH
+
+(** [digital_write] the value HIGH or LOW to the given pin which must
+   have been previously set as an output. *)
+let digital_write (p : pin) (v : pin_value) =
+  match v with
+  | LOW -> WiringPi.digital_write (int_of_pin p) 0
+  | HIGH -> WiringPi.digital_write (int_of_pin p) 1
+
+let digital_read (p : pin) : pin_value =
+  match WiringPi.digital_read (int_of_pin p) with
+  | 0 -> LOW
+  | _ -> HIGH

src/Gpio3.mli

@@ -0,0 +1,33 @@
+(** broadcom numbers *)
+val setup : unit -> unit
+
+type pin =
+ (*  3V3  |  5V   *)
+    GPIO2 | (* 5V *)
+    GPIO3 | (* GND *)
+    GPIO4 | GPIO14
+(* GND *) | GPIO15 |
+   GPIO17 | GPIO18 |
+   GPIO27 | (* GND *)
+   GPIO22 | GPIO23
+(* 3V3 *) | GPIO24 |
+   GPIO10 | (* GND *)
+    GPIO9 | GPIO25 |
+   GPIO11 | GPIO8 
+(* GND *) | GPIO7  |
+    GPIO0 | GPIO1  |
+    GPIO5 | (* GND *)
+    GPIO6 | GPIO12 |
+   GPIO13 | (* GND *)
+   GPIO19 | GPIO16 |
+   GPIO26 | GPIO20
+
+type pin_value = LOW | HIGH
+
+type mode = IN | OUT
+type pin_updn = UP | DOWN | OFF
+               
+val pin_mode : pin -> mode -> unit
+val pull_up_dn_control : pin -> pin_updn -> unit
+val digital_write : pin -> pin_value -> unit
+val digital_read : pin -> pin_value