This project involves a high DC power application. Hence it is very important to keep the safety concerns in mind while interacting with the system.
Peltier Heater, Pump and the Heat exchanger fans in the hot loop: This component is sensitive to the current. Hence the duty cycle of the PWM applied defines the average power being relayed to the device. Whenever the control for the Peltier heater is revised in the controller code, it is a safe practice to check the output of the controller pin controlling the device on the oscilloscope by connecting a simple resistive load. This gives an idea about the performance of the system and helps us determine how the actual device will react to such an input. Even a minor programming error can lead to overheating the heater and destroy the peripherals as well.
Not only malfunctions related to the Peltier can cause it to overheat. The performance and control over the peripherals can also cause the system to go haywire. For instance in the pump in the hot loop is not working, the peltier will not be able to transfer the heat to the heat exchanger and hence heat up very quickly. Same is the case with the failure in the control of the heat exchanger fans. So as a standard procedure it is good to check the control signals on the oscilloscope before hooking up the devices.
Solution we have:

As the previous check, this is a manual reset operation to alert the user about any issues with the system.

Current Sensor IC ACS 712: This is a surface mount component designed to carry 30 A current. But the connectors on which it rests may not be as capable as the IC. So there is a need to cool down the IC to avoid burn out.
Solution we have: Currently we have the cooling fans within the power source we are using, directed towards the circuit board. This basically cools down everything there in and works as a temporary solution.
Multi-value Voltage supplies for various components: On this board, we have components working at 3.3 V, 5 V, 12 V and 24 V. Hence it is very important to take care not to short out two different voltage values while trying to use oscilloscope, multimeter or something as simple as hook up wires.
Solution we have:

Troubleshooting and Understanding the GUI:

COMPORT – Enter the address of the Comport after looking it up in the device manager.
Possible Errors:
1. Invalid ComPort. Enter a valid Comport
If no COMPORT value is entered or a non-existing COMPORT is entered, you may get this error message.
Look up the correct name of the port from the ‘Device Manager’ under properties of ‘Computer’. Try to open the Serial Port after the change.

Destination Address – Enter the address of the wireless node you want the data from.
Possible Errors:
1. ‘Enter 8 Hex Characters of the MSB’:
If you enter less or more than 8 characters, this error will appear in a message box. Revise the address and enter it again in the edit box.

Number of Reads and Read Interval – The user enters the number of data point he wants and the time interval between consecutive data points.
Possible Errors:
1. Entering non integer values:
Entering floating point values here would cause an error message to pop up. Rectify the entered number.
2. Entering zero:
Entering Zero will give an error message and would default the number of reads to 20.
3. Entering alphabets in the edit box:
If the input is alphanumeric or alphabetic, an error message will pop up. Please rectify the input and retry.

Gains Kp and Ki – The user enter the gains for the PI loop controlling the Peltier heater.
Possible Errors:
1. Floating point of alphanumeric or alphabetic input by the user:
If such values are entered it will cause the GUI to throw an error message pop-up. Rectify the values based on the instruction and retry.

Default Settings: The default settings have been configured for the following:

  1. Number of iterations is 20 if invalid value is entered and used
  2. The read interval is set to 1000 ms if invalid value is entered and used.
  3. Temperature is set to 24˚C.

Before using the Set Gain Function in the GUI, one must take care to enter valid values. If valid values are not used, it may lead to unpredictable behavior of the system