MODIFIED from mbed official WiflyInterface (interface for Roving Networks Wifly modules). Numerous performance and reliability improvements (see the detailed documentation). Also, tracking changes in mbed official version to retain functional parity.

Dependents:   Smart-WiFly-WebServer PUB_WiflyInterface_Demo

Fork of WiflyInterface by mbed official

Resources

Derivative from mbed Official

  • Documentation update, improved consistency, documented parameters that were inadvertently omitted.
  • Avoid c++ string handling, which causes dynamic allocation and free, side effect, fewer CPU cycles spent for same purpose.
  • Fixed socket APIs to support non-blocking mode.
  • Increase communication baud-rate to Wifly module
  • sendCommand - added retries for improved robustness.
  • setConnectionState - method to force the connection state (used by TCPSocketServer)
  • gethostbyname - added a length parameter to the size of the buffer being written
  • flushIn - a private method to flush the input buffer
  • Changed the timeout from 500 to 2500 msec for commands - measured some at 700 to 850 msec.
  • Performance improvements - reduced some unnecessary delays.
  • Added additional security options for the wi-fi connection (that are supported by the WiFly module).
  • Added setSecurity API which permits revising the security when connecting to, or selecting from, one of several access points.
  • Improved DEBUG interface (slightly more consistent printout).
  • gathers information from the Wifly module on reboot (SW version info), which permits customizing behavior based on Wifly capabilities (like the improved security).
  • Avoid potential for recursive crash (if exit fails, it calls sendcommand, which calls exit...)
  • Update to support permissible SSID and PassCode lengths.

Robustness testing

I've had some mixed behavior with the Wifly module, some of which seems to be traceable to the module itself, and some in my derivative code. The result, after running for minutes, hours, sometimes days, it hangs and I have to reset the module.

To test, I created a fairly simple test program -

  • check for Watchdog induced reset and count it.
  • initialize the Watchdog for 60 sec timeout.
  • Init the Wifly interface and connect to my network.
  • Wait 10 seconds and force mbed_reset().

If the Watchdog induces the restart, then it is pretty clear that either:

  • The communications hung with the Wifly module causing the failure.
  • The Wifly module decided to go unresponsive.

If it gets to the end, it typically takes about 4 to 6 seconds for the boot and connect, then the 10 second delay.

But I can't really pin down the root cause easily. My strongest theory is that the Wifly module has rebooted, and since I don't store the high baud rate I configure it for, it resets back to 9600.

Also, one of the objectives for my revised send( ) is to avoid the c++ string, as that can fragment memory, and it wasn't very well bounded in behavior.

Latest tests:

Warm BootsWatchdog EventsNotes
100's30An early version of my derivative WiflyInterface, including my derivative of "send( )" API. Let's call this version 0.1.
26684My derivative WiflyInterface, but with the mbed official "send( )" API. Much improved. This was over the course of about 12 hours.
24003Most recent derivative - incremental change to "send( )", but this relative number does not rule out the Wifly module itself.

I think with these numbers, +/- 1 means that the changes have had no measurable effect. Which is good, since this incremental change eliminates the c++ string handling.

Test Software

This is pieces of a test program, clipped and copied to here. What I have compiled and run for hours and hours is almost exactly what you see. This uses this simple Watchdog library.

#include "mbed.h"
#include "WiflyInterface.h"
#include "Watchdog.h"

Serial pc(USBTX, USBRX);

Watchdog wd;
extern "C" void mbed_reset();

// Pinout for SmartBoard
WiflyInterface wifly(p9, p10, p30, p29, "ssid", "pass", WPA);

int main() {
    pc.baud(460800);                         // I like a snappy terminal
    
    wd.Configure(60.0);                     // Set time limit for the test to 1 minute
    LPC_RTC->GPREG0++;                      // Count boots here
    if (wd.WatchdogCausedReset()) {
        LPC_RTC->GPREG1++;                  // Count Watchdog events here
        pc.printf("\r\n\r\nWatchdog event.\r\n");
    }
    pc.printf("\r\nWifly Test: %d boots, %d watchdogs. %s %s\r\n", LPC_RTC->GPREG0, LPC_RTC->GPREG1, __DATE__, __TIME__);
    
    wifly.init(); // use DHCP
    pc.printf("Connect...  ");
    while (!wifly.connect());               // join the network
    pc.printf("Address is %s.  ", wifly.getIPAddress());
    pc.printf("Disconnect...  ");
    wifly.disconnect();
    pc.printf("OK. Reset in 10 sec...\r\n");
    wait(10);
    if (pc.readable()) {
        if (pc.getc() == 'r') {             // secret 'r'eset of the counters
            LPC_RTC->GPREG0 = 0;
            LPC_RTC->GPREG1 = 0;
            pc.printf("counters reset\r\n");
        }
    }
    mbed_reset();                           // reset here indicates successful communication
}
Committer:
samux
Date:
Thu Dec 20 15:08:58 2012 +0000
Revision:
4:0bcec6272784
Parent:
1:fb4494783863
Child:
7:b3d740f89f27
Child:
59:8e15d2ca7bd5
proper join after reboot - increase size flush

Who changed what in which revision?

UserRevisionLine numberNew contents of line
samux 1:fb4494783863 1 /* Copyright (C) 2012 mbed.org, MIT License
samux 1:fb4494783863 2 *
samux 1:fb4494783863 3 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
samux 1:fb4494783863 4 * and associated documentation files (the "Software"), to deal in the Software without restriction,
samux 1:fb4494783863 5 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
samux 1:fb4494783863 6 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
samux 1:fb4494783863 7 * furnished to do so, subject to the following conditions:
samux 1:fb4494783863 8 *
samux 1:fb4494783863 9 * The above copyright notice and this permission notice shall be included in all copies or
samux 1:fb4494783863 10 * substantial portions of the Software.
samux 1:fb4494783863 11 *
samux 1:fb4494783863 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
samux 1:fb4494783863 13 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
samux 1:fb4494783863 14 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
samux 1:fb4494783863 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
samux 1:fb4494783863 16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
samux 1:fb4494783863 17 */
samux 1:fb4494783863 18
samux 1:fb4494783863 19 #include "UDPSocket.h"
samux 1:fb4494783863 20
samux 1:fb4494783863 21 #include <string>
samux 1:fb4494783863 22 #include <algorithm>
samux 1:fb4494783863 23
samux 1:fb4494783863 24 UDPSocket::UDPSocket()
samux 1:fb4494783863 25 {
samux 1:fb4494783863 26 endpoint_configured = false;
samux 1:fb4494783863 27 endpoint_read = false;
samux 1:fb4494783863 28 }
samux 1:fb4494783863 29
samux 1:fb4494783863 30 int UDPSocket::init(void)
samux 1:fb4494783863 31 {
samux 1:fb4494783863 32 wifi->setProtocol(UDP);
samux 1:fb4494783863 33 wifi->exit();
samux 1:fb4494783863 34 return 0;
samux 1:fb4494783863 35 }
samux 1:fb4494783863 36
samux 1:fb4494783863 37 // Server initialization
samux 1:fb4494783863 38 int UDPSocket::bind(int port)
samux 1:fb4494783863 39 {
samux 1:fb4494783863 40 char cmd[17];
samux 1:fb4494783863 41
samux 1:fb4494783863 42 // set local port
samux 1:fb4494783863 43 sprintf(cmd, "set i l %d\r", port);
samux 1:fb4494783863 44 if (!wifi->sendCommand(cmd, "AOK"))
samux 1:fb4494783863 45 return -1;
samux 4:0bcec6272784 46
samux 4:0bcec6272784 47 // save
samux 4:0bcec6272784 48 if (!wifi->sendCommand("save\r", "Stor"))
samux 4:0bcec6272784 49 return -1;
samux 4:0bcec6272784 50
samux 4:0bcec6272784 51 // reboot
samux 4:0bcec6272784 52 wifi->reboot();
samux 4:0bcec6272784 53
samux 4:0bcec6272784 54 // set udp protocol
samux 4:0bcec6272784 55 wifi->setProtocol(UDP);
samux 4:0bcec6272784 56
samux 4:0bcec6272784 57 // connect the network
samux 4:0bcec6272784 58 if (wifi->isDHCP()) {
samux 4:0bcec6272784 59 if (!wifi->sendCommand("join\r", "DHCP=ON", NULL, 10000))
samux 4:0bcec6272784 60 return -1;
samux 4:0bcec6272784 61 } else {
samux 4:0bcec6272784 62 if (!wifi->sendCommand("join\r", "Associated", NULL, 10000))
samux 4:0bcec6272784 63 return -1;
samux 4:0bcec6272784 64 }
samux 4:0bcec6272784 65
samux 4:0bcec6272784 66 // exit
samux 1:fb4494783863 67 wifi->exit();
samux 4:0bcec6272784 68 wifi->flush();
samux 1:fb4494783863 69 return 0;
samux 1:fb4494783863 70 }
samux 1:fb4494783863 71
samux 1:fb4494783863 72 // -1 if unsuccessful, else number of bytes written
samux 1:fb4494783863 73 int UDPSocket::sendTo(Endpoint &remote, char *packet, int length)
samux 1:fb4494783863 74 {
samux 1:fb4494783863 75 Timer tmr;
samux 1:fb4494783863 76 int idx = 0;
samux 1:fb4494783863 77
samux 1:fb4494783863 78 confEndpoint(remote);
samux 1:fb4494783863 79
samux 1:fb4494783863 80 tmr.start();
samux 1:fb4494783863 81
samux 1:fb4494783863 82 while ((tmr.read_ms() < _timeout) || _blocking) {
samux 1:fb4494783863 83
samux 1:fb4494783863 84 idx += wifi->send(packet, length);
samux 1:fb4494783863 85
samux 1:fb4494783863 86 if (idx == length)
samux 1:fb4494783863 87 return idx;
samux 1:fb4494783863 88 }
samux 1:fb4494783863 89 return (idx == 0) ? -1 : idx;
samux 1:fb4494783863 90 }
samux 1:fb4494783863 91
samux 1:fb4494783863 92 // -1 if unsuccessful, else number of bytes received
samux 1:fb4494783863 93 int UDPSocket::receiveFrom(Endpoint &remote, char *buffer, int length)
samux 1:fb4494783863 94 {
samux 1:fb4494783863 95 Timer tmr;
samux 1:fb4494783863 96 int idx = 0;
samux 1:fb4494783863 97 int nb_available = 0;
samux 1:fb4494783863 98 int time = -1;
samux 1:fb4494783863 99
samux 1:fb4494783863 100 if (_blocking) {
samux 1:fb4494783863 101 while (1) {
samux 1:fb4494783863 102 nb_available = wifi->readable();
samux 1:fb4494783863 103 if (nb_available != 0) {
samux 1:fb4494783863 104 break;
samux 1:fb4494783863 105 }
samux 1:fb4494783863 106 }
samux 1:fb4494783863 107 }
samux 1:fb4494783863 108
samux 1:fb4494783863 109 tmr.start();
samux 1:fb4494783863 110
samux 1:fb4494783863 111 while (time < _timeout) {
samux 1:fb4494783863 112
samux 1:fb4494783863 113 nb_available = wifi->readable();
samux 1:fb4494783863 114 for (int i = 0; i < min(nb_available, length); i++) {
samux 1:fb4494783863 115 buffer[idx] = wifi->getc();
samux 1:fb4494783863 116 idx++;
samux 1:fb4494783863 117 }
samux 1:fb4494783863 118
samux 1:fb4494783863 119 if (idx == length) {
samux 1:fb4494783863 120 break;
samux 1:fb4494783863 121 }
samux 1:fb4494783863 122
samux 1:fb4494783863 123 time = tmr.read_ms();
samux 1:fb4494783863 124 }
samux 1:fb4494783863 125
samux 1:fb4494783863 126 readEndpoint(remote);
samux 1:fb4494783863 127 return (idx == 0) ? -1 : idx;
samux 1:fb4494783863 128 }
samux 1:fb4494783863 129
samux 1:fb4494783863 130 bool UDPSocket::confEndpoint(Endpoint & ep)
samux 1:fb4494783863 131 {
samux 1:fb4494783863 132 char * host;
samux 1:fb4494783863 133 char cmd[30];
samux 1:fb4494783863 134 if (!endpoint_configured) {
samux 1:fb4494783863 135 host = ep.get_address();
samux 1:fb4494783863 136 if (host[0] != '\0') {
samux 1:fb4494783863 137 // set host
samux 1:fb4494783863 138 sprintf(cmd, "set i h %s\r", host);
samux 1:fb4494783863 139 if (!wifi->sendCommand(cmd, "AOK"))
samux 1:fb4494783863 140 return false;
samux 1:fb4494783863 141
samux 1:fb4494783863 142 // set remote port
samux 1:fb4494783863 143 sprintf(cmd, "set i r %d\r", ep.get_port());
samux 1:fb4494783863 144 if (!wifi->sendCommand(cmd, "AOK"))
samux 1:fb4494783863 145 return false;
samux 1:fb4494783863 146
samux 1:fb4494783863 147 wifi->exit();
samux 1:fb4494783863 148 endpoint_configured = true;
samux 1:fb4494783863 149 return true;
samux 1:fb4494783863 150 }
samux 1:fb4494783863 151 }
samux 1:fb4494783863 152 return true;
samux 1:fb4494783863 153 }
samux 1:fb4494783863 154
samux 1:fb4494783863 155 bool UDPSocket::readEndpoint(Endpoint & ep)
samux 1:fb4494783863 156 {
samux 1:fb4494783863 157 char recv[256];
samux 1:fb4494783863 158 int begin = 0;
samux 1:fb4494783863 159 int end = 0;
samux 1:fb4494783863 160 string str;
samux 1:fb4494783863 161 string addr;
samux 1:fb4494783863 162 int port;
samux 1:fb4494783863 163 if (!endpoint_read) {
samux 1:fb4494783863 164 if (!wifi->sendCommand("get ip\r", NULL, recv))
samux 1:fb4494783863 165 return false;
samux 1:fb4494783863 166 wifi->exit();
samux 1:fb4494783863 167 str = recv;
samux 1:fb4494783863 168 begin = str.find("HOST=");
samux 1:fb4494783863 169 end = str.find("PROTO=");
samux 1:fb4494783863 170 if (begin != string::npos && end != string::npos) {
samux 1:fb4494783863 171 str = str.substr(begin + 5, end - begin - 5);
samux 1:fb4494783863 172 int pos = str.find(":");
samux 1:fb4494783863 173 if (pos != string::npos) {
samux 1:fb4494783863 174 addr = str.substr(0, pos);
samux 1:fb4494783863 175 port = atoi(str.substr(pos + 1).c_str());
samux 1:fb4494783863 176 ep.set_address(addr.c_str(), port);
samux 1:fb4494783863 177 endpoint_read = true;
samux 1:fb4494783863 178 wifi->flush();
samux 1:fb4494783863 179 return true;
samux 1:fb4494783863 180 }
samux 1:fb4494783863 181 }
samux 1:fb4494783863 182 wifi->flush();
samux 1:fb4494783863 183 }
samux 1:fb4494783863 184 return false;
samux 1:fb4494783863 185 }