startKIT not booting up
Posted: Mon Mar 29, 2021 10:44 am
I appreciate the startKIT is now obsolete, but I hope somebody might still be able to comment on an issue I'm having with the ones I still have in my lab.
I have several copies of a custom PCB host board (with some fairly simple functionality on it such as an optical relay, some constant-current drivers for high-powered LED outputs, etc) that is boxed up with external connectors on the box, including a 25-pin D connector. One one particular custom host board, if the 25-pin D cable is plugged in (even if the other end is connected to nothing) the startKIT board fails to power up at start of day. It gets stuck indefinitely in the initial startup state that normally lasts ~0.1s where the LEDs are dimly lit. This problem occurs with either of two startKIT units that I plug in to the host board. Another nominally-identical host board does not exhibit the problem.
A further piece of potentially-relevant information: the guy who built me the custom host board insisted that it did not matter whether the startKIT was powered via the micro-USB port (as specified in the hardware manual) or via the 5V pin headers on the startKIT board - so it is powered via the latter.
So, my question is: can anybody suggest what I might be able to do to prevent this power-up problem? I have a vague suspicion that the problem could be suppressed with a carefully-placed capacitor, if only I knew what and where to place it...
I have several copies of a custom PCB host board (with some fairly simple functionality on it such as an optical relay, some constant-current drivers for high-powered LED outputs, etc) that is boxed up with external connectors on the box, including a 25-pin D connector. One one particular custom host board, if the 25-pin D cable is plugged in (even if the other end is connected to nothing) the startKIT board fails to power up at start of day. It gets stuck indefinitely in the initial startup state that normally lasts ~0.1s where the LEDs are dimly lit. This problem occurs with either of two startKIT units that I plug in to the host board. Another nominally-identical host board does not exhibit the problem.
A further piece of potentially-relevant information: the guy who built me the custom host board insisted that it did not matter whether the startKIT was powered via the micro-USB port (as specified in the hardware manual) or via the 5V pin headers on the startKIT board - so it is powered via the latter.
So, my question is: can anybody suggest what I might be able to do to prevent this power-up problem? I have a vague suspicion that the problem could be suppressed with a carefully-placed capacitor, if only I knew what and where to place it...