David Smart
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
- SmartBoard - Wifly is a small adapter I created to plug in (another) adapter to my baseboard.
- SmartBoard - Baseboard is a baseboard I designed for a variety of small projects.
- Cookbook - WiflyInterface, especially the "More Details" section.
- Components - WiFly
- Search - WiflyInterface
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
}
Revision 70:83e420b0d3e1, committed 2015-12-14
- Comitter:
- WiredHome
- Date:
- Mon Dec 14 12:11:20 2015 +0000
- Parent:
- 69:a4064f7e3529
- Child:
- 72:9499f5c1e00b
- Commit message:
- Minor refactoring to eliminate wasted operations, and adapt to firmware v4.75
Changed in this revision
| Wifly/Wifly.cpp | Show annotated file Show diff for this revision Revisions of this file |
| Wifly/Wifly.h | Show annotated file Show diff for this revision Revisions of this file |
--- a/Wifly/Wifly.cpp Fri May 02 00:10:34 2014 +0000
+++ b/Wifly/Wifly.cpp Mon Dec 14 12:11:20 2015 +0000
@@ -32,8 +32,6 @@
// How to use this debug macro
//
-// #define DEBUG "myfile"
-// #include "Utility.h"
// ...
// INFO("Stuff to show %d", var); // new-line is automatically appended
// [I myfile 23] Stuff to show 23\r\n
@@ -203,14 +201,16 @@
{
INFO("join");
//join the network (10s timeout)
- if (state.dhcp) {
- if (!sendCommand("join\r", "DHCP=ON", NULL, 10000))
+ if (state.dhcp && swVersion < 4.75) {
+ if (!sendCommand("join\r", "DHCP=ON", NULL, 10000)) // possibly older SW did this
return false;
} else {
- if (!sendCommand("join\r", "Associated", NULL, 10000))
+ if (!sendCommand("join\r", "Associated!", NULL, 10000)) // This for most uses
return false;
}
+ INFO(" join exit");
exit();
+ INFO(" join end.");
state.associated = true;
return true;
}
@@ -368,12 +368,16 @@
bool Wifly::sendCommand(const char * cmd, const char * ack, char * res, int timeout)
{
int tries = 1;
-
+ Timer t;
+
INFO("sendCommand");
- while (tries <= 2) {
+ t.start();
+ while (tries <= 3) {
if (cmdMode()) { // some influences to the wifi module sometimes kick it out
if (send(cmd, strlen(cmd), ack, res, timeout) >= 0) {
INFO(" sendCommand - success");
+ t.stop();
+ INFO(" sendCommand - success in %f", t.read());
return true;
}
}
@@ -381,7 +385,7 @@
ERR("sendCommand: failure %d when sending: %s", tries, cmd);
tries++;
}
- INFO(" sendCommand - failure");
+ INFO(" sendCommand - failure in %f", t.read());
send("exit\r", 5, "EXIT");
return false;
}
@@ -397,7 +401,7 @@
return true;
#else // for deeper debugging
// Quick verify to ensure we really are in cmd mode
- flushIn(0);
+ //flushIn(0);
//INFO(" send \\r to test for cmdMode");
if (send("\r", 1, ">") == 1) {
//INFO(" is cmdMode");
@@ -487,6 +491,7 @@
void Wifly::reset()
{
reset_pin = 0;
+ INFO("RESET ACTIVATED");
wifi.baud(9600);
wait_ms(400);
reset_pin = 1;
@@ -543,6 +548,7 @@
bool Wifly::exit()
{
+ INFO("exit()");
if (!sendCommand("exit\r", "EXIT")) {
ERR(" failed to exit.");
return false;
@@ -598,72 +604,71 @@
Timer tmr;
int result = 0;
- INFO("will send: %s\r\n",str);
+ INFO("will send: %s",str);
attach_rx(false);
flushIn();
- if (!ACK || !strcmp(ACK, "NO")) {
- for (int i = 0; i < len; i++)
- result = (putc(str[i]) == str[i]) ? result + 1 : result;
- } else {
- flushIn();
- tmr.start();
- for (int i = 0; i < len; i++)
- result = (putc(str[i]) == str[i]) ? result + 1 : result;
+ for (int i = 0; i < len; i++)
+ result = (putc(str[i]) == str[i]) ? result + 1 : result;
+ INFO(" data sent.");
+ tmr.start();
+ if (ACK) {
while (1) {
if (tmr.read_ms() > timeout) {
- flushIn();
- WARN("timeout awaiting '%s'", ACK);
+ //flushIn();
+ WARN("timeout awaiting '%s' in (%f)", ACK, tmr.read());
attach_rx(true);
return -1;
} else if (wifi.readable()) {
read = wifi.getc();
+ #if DEBUG
+ std::printf("%c", read);
+ #endif
//printf("%02X ", read);
if (tolower(read) != tolower(ACK[ackIndex]))
ackIndex = 0;
if (tolower(read) == tolower(ACK[ackIndex])) {
ackIndex++;
if (ackIndex == strlen(ACK)) {
- flushIn();
+ //flushIn();
break;
}
}
}
}
- INFO("check: ACK '%s' received", ACK);
+ INFO("check: ACK '%s' received in (%f)", ACK, tmr.read());
+ if (strcmp(str,"exit") != 0)
+ flushIn();
attach_rx(true);
return result;
}
- //the user wants the result from the command (ACK == NULL, res != NULL)
+ // the user wants the result from the command (ACK == NULL, res != NULL)
if ( res != NULL) {
int i = 0;
- Timer timeout;
- timeout.start();
- tmr.reset();
+ int lastStamp = tmr.read_ms();
+ //Timer timeout;
+ //timeout.start();
+ //tmr.reset();
while (1) {
- if (timeout.read() > 2) {
+ if (tmr.read_ms() > timeout) { // crash and burn timeout...
if (i == 0) {
res = NULL;
break;
}
res[i] = '\0';
- WARN("2 sec timeout: %s", res);
+ WARN(" hit user %d msec timeout: %s", timeout, res);
break;
} else {
- if (tmr.read_ms() > 300) {
+ if ((tmr.read_ms() - lastStamp) > 300) { // timeout since last char suggests done...
res[i] = '\0';
//WARN("user str: %s", res);
break;
}
- if (wifi.readable()) {
- tmr.start();
+ while (wifi.readable()) {
+ lastStamp = tmr.read_ms();
read = wifi.getc();
- //printf("%02X ", read);
- // we drop \r and \n
- //if ( read != '\r' && read != '\n') {
- res[i++] = read;
- //}
+ res[i++] = read;
}
}
}
@@ -671,13 +676,14 @@
}
flushIn();
attach_rx(true);
- INFO("result: %d", result)
+ INFO("result: %d in (%f)", result, tmr.read())
return result;
}
void Wifly::flushIn(int timeout_ms)
{
Timer tmr;
+ int lastStamp;
#if 1 and defined(DEBUG)
char chatter[500];
int count = 0;
@@ -685,10 +691,11 @@
#endif
if (timeout_ms <= 0) {
- timeout_ms = 1; // 2 * 10000 / baudrate; // compute minimal timeout
+ timeout_ms = 30; // 2 * 10000 / baudrate; // compute minimal timeout
}
tmr.start();
- while (wifi.readable() || (tmr.read_ms() < timeout_ms)) {
+ lastStamp = tmr.read_ms();
+ while (wifi.readable() || ((tmr.read_ms() - lastStamp) < timeout_ms)) {
if (wifi.readable()) {
#if 1 and defined(DEBUG)
c = wifi.getc();
@@ -698,14 +705,15 @@
#else
wifi.getc();
#endif
- tmr.reset();
- tmr.start(); // start should not be necessary
+ lastStamp = tmr.read_ms();
}
}
#if 1 and defined(DEBUG)
chatter[count] = '\0';
if (count && (count > 2 || chatter[0] != '\r' || chatter[1] != '\n')) {
- INFO("Wifly::flushIn(%d) {%s}", count, chatter);
+ INFO("Wifly::flushIn(%d) {%s} in (%f)", count, chatter, tmr.read());
+ } else {
+ INFO("Wifly::flushIn() empty in [%d] (%f)", lastStamp, tmr.read());
}
#endif
}
--- a/Wifly/Wifly.h Fri May 02 00:10:34 2014 +0000
+++ b/Wifly/Wifly.h Mon Dec 14 12:11:20 2015 +0000
@@ -249,29 +249,35 @@
bool close();
/**
- * Send a string to the wifi module by serial port. This function desactivates the user interrupt handler when a character is received to analyze the response from the wifi module.
+ * Send a string to the wifi module by serial port. This function desactivates
+ * the user interrupt handler when a character is received to analyze the response
+ * from the wifi module.
+ *
* Useful to send a command to the module and wait a response.
*
- *
* @param str string to be sent
* @param len string length
- * @param ACK string which must be acknowledge by the wifi module. If ACK == NULL, no string has to be acknoledged. (default: "NO")
- * @param res this field will contain the response from the wifi module, result of a command sent. This field is available only if ACK = "NO" AND res != NULL (default: NULL)
+ * @param ACK string which must be acknowledge by the wifi module.
+ * If ACK == NULL, no string has to be acknowledged. (default: NULL)
+ * @param res this field will contain the response from the wifi module,
+ * result of a command sent. This field is available only
+ * if ACK == NULL AND res != NULL (default: NULL)
* @param timeout is the time in msec to wait for the acknowledge
*
- * @return true if ACK has been found in the response from the wifi module. False otherwise or if there is no response in 5s.
+ * @return true if ACK has been found in the response from the wifi module.
+ * @return false if there is not a correct response in the timeout.
*/
int send(const char * str, int len, const char * ACK = NULL, char * res = NULL, int timeout = DEFAULT_WAIT_RESP_TIMEOUT);
/**
- * Send a command to the wify module. Check if the module is in command mode. If not enter in command mode
+ * Put the device in command mode.
*
* @param str string to be sent
* @param ACK string which must be acknowledge by the wifi module. If ACK == NULL, no string has to be acknoledged. (default: "NO")
* @param res this field will contain the response from the wifi module, result of a command sent. This field is available only if ACK = "NO" AND res != NULL (default: NULL)
* @param timeout is the time in msec to wait for the acknowledge
*
- * @return true if successful
+ * @return true if successful, false if it failed.
*/
bool sendCommand(const char * cmd, const char * ack = NULL, char * res = NULL, int timeout = DEFAULT_WAIT_RESP_TIMEOUT);