CC3200 Benjamin Cabe MQTT Demo with OOB example ending in FaultIsr

Vinu,

I'm saying that if you have more than one task other than a dedicated MQTT task, then the Paho MQTT library won't work as is. In this case, the MQTT library requires modification. You can test this by putting everything in one task and seeing that it runs without hitting faultISR().

FreeRTOS utilizes the system timer to perform context switching (the process of storing and restoring the state (context) of a process or thread so that execution can be resumed from the same point at a later time). The MQTT library also utilizes this system timer and overwrites the configuration and interrupt handler associated with it, basically it breaks FreeRTOS scheduling. MQTT requires a timing system in order to keep track of keep alive timers, ping timers, timeout timers for sending and receiving data, etc.

Step 1 is to remove the code that utilizes the system timers from MQTT.

Steps 2 and 3 are to recreate this code to instead utilize one of the general purpose timers on the CC3200, which has 4 instances of 32 bit user programmable general purpose timers. You can basically just modify "MQTTCC3200.h" and "MQTTCC3200.c" and your initialization code to accomplish this.

2) Enable another interrupt on one of the timers and have it trigger every ms. This example uses timer A and makes its interrupt fire every ms.

Use these functions from "timer_if.h" in the common folder of the CC3200SDK and add this to your initialization code
//Init Timer
Timer_IF_Init(PRCM_TIMERA0, TIMERA0_BASE, TIMER_CFG_PERIODIC, TIMER_A, 0);

// Setup the interrupt for the timer timeouts.
Timer_IF_IntSetup(TIMERA0_BASE, TIMER_A, milliIntHandler);

//Start the timer (with 1 ms intervals)
Timer_IF_Start(TIMERA0_BASE, TIMER_A, PERIODIC_TEST_CYCLES / 1000);

3) It's interrupt handler should increment a software timer (integer representing milliseconds)
This step is basically already done. As long as the interrupt handler defined in "MQTTCC3200.h" is named milliIntHandler like in step 2.