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coredump-ch / nixie-counter

"People present" counter for SpaceAPI, using nixie tubes.
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Turning on NCH6100HV with Blue Pill #5

Closed dbrgn closed 4 years ago

dbrgn commented 4 years ago

Should the power supply for the nixie tubes be connected to the blue pill so we can turn it on and off with a GPIO?

When pulling SHDN pin high, the power supply turns off.

Rationale: When the power supply is off by default, we can initialize everything (including WiFi) before turning on the tubes.

Requirements: The GPIO pin would need to be high at boot, otherwise this would be of little use.

dbrgn commented 4 years ago

As far as I can tell the GPIO pins are configured as inputs after reset, which means that the tube power supply would get power for a few milliseconds before we can turn it off. So this would be of little use if we want to control the power draw when powering on.

While the power supply would run when SHDN is connected directly to GND (or left floating), the tubes are off by default, so I don't think this is a big issue.