ESP8266, Client connect via Ticker - callback

Question

Hey Stack Overflow Community,
big thanks to this community, is helping me a lot. However for now i am stucked since a while and cant find any solutions in the web.
Working with the ESP8266 chip is a lot of fun. There are tons of easy examples out there how to connect to servers... using the ESP. At the moment i am writing nested classes to create different client connections.
I like creating "subtasks" using a Ticker/Timer objects (periodic or once callback) to free the cpu. However, as soon i created a new WiFiClient object and the callback function of a Ticker object is invoked, i ll receive a runtime error while the client tries to connect to the host.
It would be a mess to include my whole project and classes, so i wrote this small code, however, it will illustrate my problem.
Both functions void post(int var) and void postPtr(int var) can be call individually, e.g. in the loop(), successfully. However as soon i attach one of those functions to a ticker callback i'll get a run time error.
#ifdef DEBUG_ESP_PORT
#define DEBUG_MSG(...) DEBUG_ESP_PORT.printf( __VA_ARGS__ )
#define debugmode 1
#else
#define debugmode 0
#define DEBUG_MSG(...)
#endif
#include <ESP8266WiFi.h>
#include <Ticker.h>
#ifndef STASSID
#define STASSID "###SSID###"
#define STAPSK "###PWK###"
#endif
Ticker myTicker;
Ticker* myTickerPtr;
WiFiClient* myClientPtr;
const char* ssid = STASSID;
const char* password = STAPSK;
const char* host = "192.168.10.40";
const uint16_t port = 8080;
const char* postMessage = "POST /plug HTTP/1.1\r\nContent-Type: application/x-www-form-urlencoded; charset=UTF-8\r\nContent-Length: 14\r\nConnection: close\r\n\r\nname=2&value=1";
static int prevTime=millis();
int cnt=0;
int packages=0;
int speed=0;
//#########################################################################
// checking time duration for code execution
int time() {
int tmp = millis();
int value = tmp - prevTime;
prevTime = tmp;
return value;
}
//#########################################################################
// simple connection / package speed test
void speedtest() {
speed = (cnt - packages)*5;
packages = cnt;
}
//#########################################################################
// connect to host, send a post message, stop connection
void post(int var) {
WiFiClient client;
DEBUG_MSG("[DONE %dms] Client[%d] waiting for connection... \n", time(), var);
while (!client.connect(host, port)) {delay(10);}
DEBUG_MSG("[DONE %dms] Client[%d] connected \n", time(), var);
client.println(postMessage);
client.printf("[DONE %dms] Client[%d] Data Package[%d] Sent. Avg speed: %d\n\n", time(), var, cnt, speed);
DEBUG_MSG("[DONE %dms] Client[%d] Data Package[%d] Sent. Avg speed: %d\n\n", time(), var, cnt, speed);
client.stop();
cnt++;
}
//#########################################################################
// connect to host, send a post message, stop connection (using a WifiClient Pointer)
void postPtr(int var) {
myClientPtr = new WiFiClient;
DEBUG_MSG("[DONE %dms] ClientPtr[%d] waiting for connection... \n", time(), var);
while (!myClientPtr->connect(host, port)) {delay(10);}
DEBUG_MSG("[DONE %dms] ClientPtr[%d] connected \n", time(), var);
myClientPtr->println(postMessage);
myClientPtr->printf("[DONE %dms] ClientPtr[%d] Data Package[%d] Sent. Avg speed: %d\n\n", time(), var, cnt, speed);
DEBUG_MSG("[DONE %dms] ClientPtr[%d] Data Package[%d] Sent. Avg speed: %d\n\n", time(), var, cnt, speed);
myClientPtr->stop();
delete myClientPtr;
cnt++;
}
//#########################################################################
void setup() {
if (debugmode) {
Serial.begin(115200);
while (!Serial) {delay(10);}
}
DEBUG_MSG("\n\n");
DEBUG_MSG("[DONE %dms] Serial done \n", time());
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
DEBUG_MSG("[DONE %dms] Waiting for WiFi connection... \n", time());
while (!WiFi.isConnected()) { delay(10);}
DEBUG_MSG("[DONE %dms] WiFi connected. IP %s\n", time(), WiFi.localIP().toString().c_str());
myTicker.attach_ms(200, speedtest);
//R U N T I M E E R R O R - while in callback function - STACK OVERFLOW !!!
myTickerPtr = new Ticker;
myTickerPtr->once_ms(100, post, 0x02);
//or
//myTickerPtr->attach_ms(100, post, 0x02);
}
//#########################################################################
void loop() {
// calling functions, working fine...
post(0x01);
postPtr(0x01);
//ESP.deepSleep(0);
}
DEBUG MESSAGE:
[DONE 0ms] Serial done
[DONE 5ms] Waiting for WiFi connection...
[DONE 185ms] WiFi connected. IP 192.168.10.88
[DONE 101ms] Client[2] waiting for connection...
Soft WDT reset
>>>stack>>>
ctx: sys
sp: 3fffecb0 end: 3fffffb0 offset: 01b0
3fffee60: 00000000 4020e220 00000030 4010097c
3fffee70: 3ffee63c 3fffeef0 00000030 4020e220
3fffee80: 00000000 3fffeef0 3fffeef0 402034c1
3fffee90: 00001f90 3fffeea0 00000008 60000600
3fffeea0: 401052ec 001fbdcb 3ffee700 00001f90
3fffeeb0: 3ffee63c 00001f90 3fffeef0 40202c54
3fffeec0: 40204810 280aa8c0 402013f0 0000000a
3fffeed0: 3ffe87a4 0000000a 0000000a 402013fb
3fffeee0: 3ffee63c 00000002 3ffe84e0 4020266e
3fffeef0: 40204788 00000000 00001388 00000001
3fffef00: 00000000 00000000 3ffedfc0 00d99aa9
3fffef10: 4010505e 0014fa1c 3ffedfc0 60000600
3fffef20: 00d9d2f2 3ffedfc0 3ffef1a4 40230809
3fffef30: 4023084e 3fffdab0 00000000 3fffdcb0
3fffef40: 3ffedfd0 3fffdad0 3ffee6a8 402040c7
3fffef50: 40000f49 40000f49 3fffdab0 40000f49
3fffef60: 40000e19 40001878 00000002 00000000
3fffef70: 3fffff10 ffffffff ffffffff 401049d0
3fffef80: 401049d6 00000002 00000000 54e55bf8
3fffef90: 4010000d 6f3d99f3 6dad4d79 c13de55d
3fffefa0: 00000000 3fffef3c 00000000 3fffff38
3fffefb0: 3fffffc0 00000000 00000000 feefeffe
3fffefc0: feefeffe feefeffe feefeffe feefeffe
3fffefd0: feefeffe feefeffe feefeffe feefeffe
3fffefe0: feefeffe feefeffe feefeffe feefeffe
...
...
3ffffc20: feefeffe feefeffe feefeffe feefeffe
3ffffc30: feefeffe feefeffe feefeffe feefeffe
3ffffc40: feefeffe feefeffe feefeffe feefeffe
3ffffc50: feefeffe feefeffe feefeffe feefeffe
3ffffc60: feefeffe feefeffe feefeffe feefeffe
3ffffc70: 00000003 00000000 0000000a 00000000
3ffffc80: 00000003 00000000 0000000a 00000000
3ffffc90: feefeffe feefeffe feefeffe feefeffe
3ffffca0: 00000000 a0000000 00000000 0000001c
3ffffcb0: 00003000 feefeffe 00003000 00000000
3ffffcc0: 3ffffe20 00000000 3ffffe20 4020bf66
3ffffcd0: 0000a000 3ffffdc3 3ffe8e01 00000008
3ffffce0: 4022a65a 3ffeedec 40207ce0 0000000d
3ffffcf0: 3ffffe20 0000000d 3ffffe20 4020bf66
3ffffd00: 3ffffd80 3ffef434 3ffffd30 00000000
3ffffd10: 3ffe8cb0 40229717 3ffeedec 4020bea0
3ffffd20: 3ffffe20 3ffef434 3ffffd80 40207de0
3ffffd30: 0000000d 0000002c 0000002c 00000001
3ffffd40: 00000000 00000001 3ffffe20 4020bf66
3ffffd50: 3ffffdc3 3ffe8681 00000000 4021f23f
3ffffd60: 3ffed780 4021ee10 40221480 3ffe8681
3ffffd70: 00000000 3ffe8682 3ffffe20 4020c150
3ffffd80: 00000000 0000000d 00000000 00000000
3ffffd90: 0000000d 0000002f 40302073 3ffed878
3ffffda0: 3ffed8b0 40221480 3ffed780 aa55aa55
3ffffdb0: 3ffed110 40220d8c 3ffed08c 33000012
3ffffdc0: 00353239 4021edd4 3ffed110 00000012
3ffffdd0: 4021ed9f 3ffed08c 00000000 40232c0d
3ffffde0: 3fffff50 3fffff20 00000010 3ffe8304
3ffffdf0: 00000002 00000000 00000020 401014c2
3ffffe00: 3ffe8cb2 401048ac 3ffec420 3ffee6a8
3ffffe10: 00000001 40103acf 3ffece78 402096c9
3ffffe20: 40103f32 3ffe84ec 00000010 ffff0208
3ffffe30: 3ffffed0 0000003f 3fffc200 00000022
3ffffe40: 40103a16 0000002c 7fffffff 00000002
3ffffe50: 0000012c 00000030 0000001e ffffffff
3ffffe60: 4010288b 00080000 3fffff40 40203d5c
3ffffe70: 00000000 0000000a 00002200 4000050c
3ffffe80: 00000000 00000000 0000001f 401051a9
3ffffe90: 00000000 00000000 0000001f 401051a9
3ffffea0: 4000050c 00000030 00000010 ffffffff
3ffffeb0: 402041d4 00000030 00000011 ffffffff
3ffffec0: 402041d4 000000a0 3fffc704 00000001
3ffffed0: 00000000 00000000 00000000 fffffffe
3ffffee0: ffffffff 3fffc6fc 00000001 3ffe851c
3ffffef0: 00000000 3fffdad0 3ffee6a8 00000030
3fffff00: 401052ec 0014fa1c 3ffef1a4 00000000
3fffff10: 3ffedfc0 3ffef1a4 00000020 401009a2
3fffff20: 00000000 0014800a 402036bc 3ffef42c
3fffff30: 00000000 00000064 00000002 4020369e
3fffff40: 4020262c 4020e220 00000020 401009a2
3fffff50: 00000000 3ffee608 00000014 3ffee6a8
3fffff60: 00000f55 3ffee608 3ffef42c 4020259c
3fffff70: 00000000 00000000 00000000 00000000
3fffff80: 402023ac 580aa8c0 402043e0 402043cc
3fffff90: 00000000 00000000 00000001 4020415d
3fffffa0: 3fffdad0 00000000 3ffee674 402041ee
<<<stack<<<
ets Jan 8 2013,rst cause:2, boot mode:(1,6)
ets Jan 8 2013,rst cause:4, boot mode:(1,6)
wdt reset
I would appreciate any help, recommendations or advices. Thanks for reading :D