1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
/*------------------------------------------------------------------------------
RPiGPIOMex.c -- A simple MEX file for GPIO control on the RaspberryPi
On Octave, compile with:
mex -v -g RPiGPIOMex.c -lwiringPi
------------------------------------------------------------------------------
Copyright (C) 2016 - 2023 Mario Kleiner
This program is licensed under the MIT license.
A copy of the license can be found in the License.txt file inside the
Psychtoolbox-3 top level folder.
------------------------------------------------------------------------------*/
/* Octave includes: */
#include "mex.h"
/* System includes */
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
/* wiringPi library for RPi GPIO control includes */
#include <wiringPi.h>
static bool firstTime = 1;
void exitfunc(void)
{
// Actually nothing to do. The library does not have a shutdown function.
firstTime = 1;
}
unsigned long long nowMS(void)
{
static unsigned int thigh = 0;
static unsigned int oldT = 0;
unsigned int tlow = millis();
// 32-Bit time wraparound? Increase upper 32-Bit:
if (tlow < oldT)
thigh ++;
// Keep track of current lower 32-Bits for wraparound handling:
oldT = tlow;
// Assemble new 64-Bit time:
return ((unsigned long long) thigh) << 32 | ((unsigned long long) tlow);
}
/* waitFor 'pin' reaching target level 'waitLevel', or 'timeout' msecs elapsed. */
int waitFor(int pin, int timeout, int waitLevel)
{
// Compute deadline for timeout - -1 == Infinite wait:
unsigned long long timeoutD = (timeout >= 0) ? (nowMS() + (unsigned long long) timeout) : 0xffffffffffffffff;
// Wait for signal level not being waitLevel:
while ((nowMS() < timeoutD) && (digitalRead(pin) == waitLevel))
delayMicroseconds(200);
// Timed out?
if (digitalRead(pin) == waitLevel)
return 0;
// Wait for signal level transition to waitLevel:
while ((nowMS() < timeoutD) && (digitalRead(pin) != waitLevel))
delayMicroseconds(200);
// Timed out?
if (digitalRead(pin) != waitLevel)
return 0;
// Success:
return 1;
}
/* This is the main entry point from Octave: */
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray*prhs[])
{
int cmd, pin, arg, waitRising;
int rc;
double* out;
// Get our name for output:
const char* me = mexFunctionName();
// Special case: Called with one return argument and no input arguments. Return RPi board revision number:
if (nrhs == 0 && nlhs == 1) {
rc = piBoardRev();
plhs[0] = mxCreateDoubleMatrix(1, 1, mxREAL);
*(mxGetPr(plhs[0])) = (double) rc;
return;
}
if (nrhs < 2) {
mexPrintf("%s: A simple Octave MEX file for basic control of the RaspberryPi GPIO pins under GNU/Linux.\n\n", me);
mexPrintf("(C) 2016 - 2023 Mario Kleiner -- Licensed to you under the MIT license.\n");
mexPrintf("This file is part of Psychtoolbox-3 but should also work independently.\n\n");
mexPrintf("Pin numbers are in Broadcom numbering scheme aka BCM_GPIO numbering.\n");
mexPrintf("Mapping to physical connector pins and other restrictions and pin properties can be found at\n");
mexPrintf("http://wiringpi.com/pins or by typing the command 'pinout' into a terminal.\n\n");
mexPrintf("For testing purposes, pins 35 and 47 on a RaspberryPi 2B map to the red power and green status LEDs.\n\n");
mexPrintf("The gpio command line utility allows to setup and export pins from a shell. Octave must be run as\n");
mexPrintf("root user via 'sudo octave' or the user must be part of the 'gpio' Unix user group for non-root operation.\n\n");
mexPrintf("\n");
mexPrintf("Usage:\n\n");
mexPrintf("revision = %s;\n", me);
mexPrintf("- Return RaspberryPi board 'revision' number. Different revisions == different pinout.\n\n");
mexPrintf("state = %s(0, pin);\n", me);
mexPrintf("- Query 'state' of pin number 'pin': 1 = High, 0 = Low.\n\n");
mexPrintf("%s(1, pin, level);\n", me);
mexPrintf("- Set state of pin number 'pin' to logic level 'level': 1 = High, 0 = Low.\n\n");
mexPrintf("%s(2, pin, level);\n", me);
mexPrintf("- Set pulse-width modulation state of pin number 'pin' to level 'level': 0 - 1023.\n");
mexPrintf(" Only available on GPIO logical pin 18 (physical connector pin 12) on the RaspberryPi without extension boards.\n\n");
mexPrintf("%s(3, pin, direction);\n", me);
mexPrintf("- Set direction of pin number 'pin' to 'direction'. 1 = Output, 0 = Input.\n\n");
mexPrintf("%s(4, pin, pullMode);\n", me);
mexPrintf("- Set resistor mode of pin number 'pin' to 'pullMode'. -1 = Pull down, 1 = Pull up, 0 = None.\n");
mexPrintf(" Pin must be configured as input for pullup/pulldown resistors to work.\n\n");
mexPrintf("result = %s(5, pin, timeoutMsecs);\n", me);
mexPrintf("- Wait for rising edge on input pin number 'pin' with a timeout of 'timeoutMsecs': -1 = Infinite wait.\n");
mexPrintf(" Return 'result' status code: -1 = error, 0 = timed out, 1 = trigger received.\n");
mexPrintf(" Pin must be configured as input.\n\n");
return;
}
if (firstTime) {
// Enable return of proper error codes if wiringPi setup fails.
// We want to handle this gracefully instead of crashing:
setenv("WIRINGPI_CODES", "1", 0);
// Always use GPIO mode - requires sudo root, or user to be in 'gpio' Unix user group:
rc = wiringPiSetupGpio();
if (rc) {
mexPrintf("wiringPi init failed: Error code %i [%s]\n", rc, strerror(rc));
mexErrMsgTxt("Failed to initialize GPIO system.");
}
// Successfully connected. Register exit handler to close GPIO control
// when mex file is flushed:
mexAtExit(exitfunc);
// Ready to rock:
firstTime = 0;
}
// First argument must be the command code:
cmd = (int) mxGetScalar(prhs[0]);
// Second argument is pin number:
pin = (int) mxGetScalar(prhs[1]);
if (nrhs > 2)
arg = (int) mxGetScalar(prhs[2]);
else
arg = -1000;
switch (cmd) {
case 0: // Read input level from pin: 1 = High, 0 = Low
rc = digitalRead(pin);
plhs[0] = mxCreateDoubleMatrix(1, 1, mxREAL);
*(mxGetPr(plhs[0])) = (double) rc;
break;
case 1: // Write a new level to output pin: 1 = High, 0 = Low
if (arg < 0)
mexErrMsgTxt("New logic level of output pin missing for output pin write.");
digitalWrite(pin, arg);
break;
case 2: // NOT in sysmode: Write a new pwm level to output pin: 0 to 1024 on RPi
if (arg < 0)
mexErrMsgTxt("New pwm level of output pin missing for output pin pulse-width modulation.");
pwmWrite(pin, arg);
break;
case 3: // NOT in sysmode: Set pin mode: 1 = out, 0 = in
if (arg < 0)
mexErrMsgTxt("New opmode for pin missing for pin mode configuration.");
pinMode(pin, arg ? OUTPUT : INPUT);
break;
case 4: // NOT in sysmode: Set pullup/pulldowns: 1 = out, 0 = in
if (arg < -1)
mexErrMsgTxt("New pullup/down for pin missing for pin resistor configuration.");
pullUpDnControl(pin, (arg == 0) ? PUD_OFF : ((arg > 0) ? PUD_UP : PUD_DOWN));
break;
case 5: // Wait for rising or falling edge on given input pin via polling.
if (arg < -1)
mexErrMsgTxt("Timeout value in milliseconds missing.");
// Wait for rising edge:
waitRising = 1;
// Wait for target level with timeout:
rc = waitFor(pin, arg, waitRising);
plhs[0] = mxCreateDoubleMatrix(1, 1, mxREAL);
*(mxGetPr(plhs[0])) = (double) rc;
break;
default:
mexErrMsgTxt("Unknown command code provided!");
}
// Done.
return;
}
|
