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 Boots | Watchdog Events | Notes |
100's | 30 | An early version of my derivative WiflyInterface, including my derivative of "send( )" API. Let's call this version 0.1. |
2668 | 4 | My derivative WiflyInterface, but with the mbed official "send( )" API. Much improved. This was over the course of about 12 hours. |
2400 | 3 | Most 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
}
Revisions of Wifly/Wifly.cpp
Revision |
Date |
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52:ffc0b655a23c
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2013-12-30 |
Cleanup for compiler warning reduction. |
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51:a4831b1cb9a4
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2013-11-28 |
Documentation updates - put all files into a more similar format for the doxygen tags.; Reduce some of the verbose debugging information.; Small amount of code size reduction (reduced some redundancy) |
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50:cc173c24a316
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2013-10-12 |
Diagnostic changes only while trying to optimize performance. |
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48:b9e1152f39e3
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2013-10-11 |
Small change to the debug print to better line up with other files. |
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47:97303e1970c1
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2013-10-10 |
Fixed a defect in FixPhrase that was freeing memory that wasn't allocated. |
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46:4722f7d72aab
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2013-10-10 |
Security enhancements |
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45:21b7bbaad62b
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2013-10-10 |
Diagnostic improvements |
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43:df984bf61580
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2013-10-10 |
Dead code removal |
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42:2a6fa071aecc
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2013-10-10 |
Enhanced debugging, but fails in SendResponse(...) |
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41:698be43f9233
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2013-10-10 |
Starting to add file upload capability. |
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38:30e142b93ce4
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2013-10-09 |
Minor documentation changes |
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36:8d868fea6fe6
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2013-09-10 |
Minor modification to the accept() check for *OPEN*, as well as to the wifly send() method to check for the ACK string. This prevents it from potentially getting out of sync. |
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35:2dc12224cbd6
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2013-09-06 |
Modified a version extraction to handle both v2.36 and v4.00 (it was looking for a case sensitive match of wifly before it parsed Ver X.YY).; WiFly Ver 2.36, 09-27-2012 on RN-171; wifly-EZX Ver 4.00.1, Apr 19 2013 11:47:16 on RN-171 |
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34:52e4eec8b790
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2013-09-05 |
Major change is in how to checks for expected response. Prior code used the C++ string method of concatenation, which could continue to allocate memory to exhaustion, even if it was only interested in a few character response. |
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32:4543e91ab4bf
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2013-09-01 |
Implement the non-blocking option. The API was there to set it, but it was otherwise unused. |
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31:e4422f192d25
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2013-08-12 |
Added other security options back in. |
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30:f500260463b7
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2013-08-05 |
Add extra access point security methods supported by the Wifly module |
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29:49876a8c445b
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2013-08-04 |
Changes focused on connection reliability. A number of small changes to debug macros, while discovering that something kicks wifly out of command mode. So, the cmdMode() API forces a check. This seems to be a huge improvement. |
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28:b7c1182aed28
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2013-07-27 |
Add a delay on close. While delays are to be avoided, if there is data in the Wifly module still being sent, it appears that closing too soon can interrupt that transmission. Have not identified any synchronous way to determine the transmit is done. |
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27:8509ec4a0a0a
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2013-07-22 |
Change the flush size to 1420 and minor documentation tweaks nearby. |
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26:78a1a09afdc9
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2013-07-22 |
Modify the reboot method so it gets back in sync more easily. |
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25:a740eb74a86a
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2013-07-22 |
Improve security, and small formatting changes for more consistency. |
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24:5012a535b1d5
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2013-07-21 |
Refactored the ssid and passphrase handler to eliminate redundant code. |
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23:6e77c65ced00
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2013-07-21 |
Minor refactor on send() to share the timeout for both purposes.; Minor refactor on sendCommand to retry on failure. |
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22:62267088e95a
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2013-07-21 |
Improved the DEBUG behavior - printouts, extra \r\n, etc. |
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21:97294686b4a1
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2013-07-21 |
Add baud rate setting |
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20:906b0f951bc3
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2013-07-21 |
Add baud rate setting |
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19:b0c2488222a3
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2013-07-21 |
Efficiency - send() had 3 timers, a passed in timer which worked only when no ACK was expected, and two hard-coded timers for when the caller wanted the return ACK. Eliminated the hard-coded timers. |
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18:18ab3993d00d
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2013-07-21 |
Efficiency - add flushIn() and eliminate several inline equivalent changes.; Efficiency - largest effect was on the send() method. |
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17:213844a1864f
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2013-07-21 |
Fixed serious error - if sendCommand() failed, it would then try to exit(), which called sendCommand() - high probability of recursion to exhaustion. |
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13:7197313973a4
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2013-07-04 |
Remove idle timeout.; Remove unnecessary code.; Minor comment changes. |
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12:6270ced02019
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2013-07-01 |
Quite a bit of refactoring of the wifly interface. Most of the changes are in the Wifly.cpp file. |
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11:44563217d2b9
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2013-06-30 |
Rearranged functions to compare more easily |
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10:a594fe035b36
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2013-06-27 |
Refactoring a number of things, constructor, reset, acquisition of version information. |
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9:86105ba18d96
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2013-06-25 |
Reduction in memory allocated requirement |
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8:79415e982c32
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2013-06-25 |
When a pointer to a buffer is passed in to the APIs that can modify that buffer, good practices will also pass the size of that buffer to avoid buffer overrun. |
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7:b3d740f89f27
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2013-06-24 |
Permit TCPSocketConnection to be non-blocking. |
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6:9b25f2bc3b03
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2013-06-02 |
Removed some unnecessary delays |
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5:cc0506dc3565
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2013-05-31 |
Numerous changes, mostly to Wifly.cpp to fix performance and capabilities. |
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4:0bcec6272784
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2012-12-20 |
proper join after reboot - increase size flush |
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3:9aa05e19c62e
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2012-12-20 |
add reboot method - reboot module for accept (tcp server) |
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2:8e54830d0df7
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2012-11-24 |
set dns server name (now able to use "open host port") |
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1:fb4494783863
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2012-08-24 |
first commit |
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