Some additional info that I remember observing-
- The RFM95W module always burns out with a short between adjacent pins. In the older circuit when the main IC on the module was near the Arduino, the DIO0 pin and Vcc where shorted. In the newer circuit, with the orientation of the board reversed and connections changed, the MISO and MOSI pins were shorted.
- I had also powered this circuit with a 12V 5A SMPS. The SMPS outputs 12.25V (as measured by the INA219) while the Arduino is running and the RFM95W is sleeping. However, on a few occasions the voltage dropped to 11.2V (again measured by INA219). Since the SMPS has a max rating of 5A (which is much more than what is needed), should the voltage suddenly drop like this? Could this have anything to do with the MCP1702 regulator? Can a linear regulator cause a module to burn out like this?
I have checked the circuit for any shorts or wrong connections quite a few times. Maybe I am overlookng something obvious here but at the moment I can't think of anything other than a faulty MCP1702. @srnet What do you think? Or do you have anything specific in mind that I should check about the connections?
**My biggest confusion is how the RFM95 module burns out after running for more than 25-30hrs (with a 10-15min sleep cycle, so around 100-120 transmissions and receptions) **