BOE question with Propeller

JohnR2010

I have a project that connects to a 24volt DC power supply that is also used to run two Von Wise Actuators. The Von Wise Actuators are DC motors and my circuit doesn’t do anything with them but I do pull form the same power supply used to drive them. These motors do create some noise and I have a filtering cap across my DC voltage regulator but randomly once every 3 or 4 days my propeller resets when these motors are running. I’m 99.9% sure this is not a code problem but I do think it is a power problem. I have the BOE circuit enabled by pulling it low to ground. My question is this. If I tie the BOE to VDD (Disable BOE) will this make the propeller P8X32A-D40 more tolerant of a low voltage spike or help with my reset problem? Will the Propeller continue to run at a low voltage below 3.3 volts if I disable BOE?

localroger

Disabling BOE is unlikely to help; the reason it exists is to prevent chaotic operation which might happen if the processor undervoltages, which can randomize the contents of memory. You should probably try to beef up the filtering. Use both a large filter cap (to take out the slack from undervoltage) and a small one (for high frequency noise, since the big one will have a lot of inductance) before and after the regulator. Also feed the whole affair through a diode so if the motors pull down the power supply the regulator input filter caps won't discharge through them.

Leon

A TransGuard or something similar across the 3.3V supply and proper filtering will help a lot.

JohnR2010

Thanks guys for the input I didn’t think disabling BOE was going to be the rote to take and you all have confirmed it. I had already entertained the idea of a diode with a bigger cap in front of my power circuit. Localroger suggested the same thing so I think I will go down that road. Thanks!