DFR0959 Beetle RP2040 - No reset on power up??
KentHardage 2024-08-12 14:15:31 168 Views1 Replies I have used the Beetle DFR0282 on a number of projects and find it to be a great choice for small projects. I now need to move to a 3.3V system and would like to use the DFR0959 RP2040 Beetle. No problem having reset button on board but when system put in operation I must have reset on power up! How do I overcome this issue? This may eliminate the DFR0959 as an option unless a solution is found. Anyone solve this problem??
Well, after some reading and research on my issue I have solved the problem. Hopefully this will help someone else addressing a system problem similar to this issue. I am working on a multi board system where one board has the master CPU and provides power and communication bus(I2C) to second board.
At power up the master CPU would be hung in a state where the system did not run. When after reaching this “stable hung state” pushing the reset button on the DFR0959 would reset the software to run from the beginning.
The issue comes when the system is not on the development bench where pushing the reset button works for development but does not work when system is installed in field and a power fail occurs but system will not recover in working state when power returns leaving system in non useable “stable hung state”.
The power on sequence with multi boards and one power source and the master comm bus going between boards has to be managed by allowing time for the system to reach a stable state where the SW runs from the beginning. Adding delay at the beginning of void setup to allow boards voltage to become stable and delay later in setup to allow the begin() functions to stabilize then enter void loop after all is stable. These delays only run once in startup and I found delays of 1-2 sec is all that is required to make my system come up is a stable running state at power on. So, SW or HW reset not needed if root causes of SW design failure are addressed.
KentHardage 
