Changes between Version 2 and Version 3 of Docs/Prog/Manual/DeviceSupport/DIO

Timestamp:

11/30/09 09:22:46 (15 years ago)

Author:

Don Wilson

Comment:

--

Docs/Prog/Manual/DeviceSupport/DIO

@@ -2 +2 @@
 
 == DIO ==
+
+=== Digital I/O ===
+{{{
+echo “L000000020000000F” > /dev/mnbd
+}}}
+This sets the state of the mainboard digital outputs. The “L” is the command, the following 8 characters or four hexadecimal bytes represent the state desired. The final 8 characters or four hexadecimal bytes represent a mask of which outputs are to be affected. In this example “F” is used as the mask to set the state of all four on-board outputs.
+
+{{{
+# echo “I” > /dev/mnbd
+}}}
+This requests the status of the mainboard digital I/O.
+
+{{{
+# cat < /dev/mnbd
+}}}
+response:
+
+{{{
+# IA000000000
+}}}
+The last 8 character of the response are hexadecimal digits. Of these the first 4 digits are the state of the digital inputs. The final 4 digits are the state of the outputs. If the input 1 only is active the response is:
+
+{{{
+# IA000010000
+}}}
+If inputs one and two are active the response is:
+
+{{{
+# IA000030000
+}}}
+If inputs one, two, three, and four are active the response is:
+
+{{{
+# IA0000F0000
+}}}
+Only a single hexadecimal digit is needed to represent the state of the four mainboard inputs.
+
+||Response||Input 1||Input 2||Input 3||Input 4||
+||0||Off||Off||Off||Off||
+||1||On||Off||Off||Off||
+||2||Off||On||Off||Off||
+||3||On||On||Off||Off||
+||4||Off||Off||On||Off||
+||5||On||Off||On||Off||
+||6||Off||On||On||Off||
+||7||On||On||On||Off||
+||8||Off||Off||Off||On||
+||9||On||Off||Off||On||
+||A||Off||On||Off||On||
+||B||On||On||Off||On||
+||C||Off||Off||On||On||
+||D||On||Off||On||On||
+||E||Off||On||On||On||
+||F||On||On||On||On||
+
+''For additional structure formats refer to MainboardProtocol''
+
+The lib825 library provides functions to facilitate applications performing digital I/O tasks.
+
+{{{
+#!Lineno
+#!c
+extern uint32 g_nRepIOIntv;
+
+extern struct set_dio_struct mnbd_set_dio;
+extern struct mnbd_dio_status_struct mnbd_dio_status;
+
+// Read I/O status every 100 ms
+g_nRepIOIntv = 100;
+MnBdRequest(MNBD_DEV, MNBD_REQ_REP_IO_STATUS, NO_WAIT_ACK);
+
+sleep(1);
+
+while(1)
+{
+   if(CheckIORcv(MNBD_DEV))
+   {
+      if((mnbd_dio_status.inputs & 1) != 0)
+      {
+           // Input 1 active -- Set output 1 and break out of loop
+
+           mnbd_set_dio.output = 0x01;
+           mnbd_set_dio.mask = 0x0F;
+           MnBdRequest(0, MNBD_REQ_SET_IO_STATUS, NO_WAIT_ACK);
+           break;
+      }
+   }
+}
+
+// Stop repeating I/O status
+g_nRepIOIntv = 0;
+MnBdRequest(MNBD_DEV, MNBD_REQ_REP_IO_STATUS, NO_WAIT_ACK);
+
+}}}
+
+For digital I/O event operations refer to the DioEvent class.
 
 === DIO Events ===