Just make sure, do not want to burn my IMP, I can feed 9DC power to Powering the Breakout pins ““VIN” header”? This will lead to 3.3V Regulator…?
What about Battery input? Does that also lead to the 3.3V Regulator.
"Powering the Breakout" does NOT say it clear enough.
Do you have the April Board? You can use 5,6,9 or 12vdc. The April board has a built-in 3.3V regulator. I usually use an extra USB charger (which is 5V) that I have laying around. The wall-wart packages are tiny and easy to work with. I don’t use the USB connector, only the 5VDC power wires to VIN, but you could just use the USB connector if you don’t mind having it be a bit bulkier. You only apply power at GND and VIN (or the USB connector). The breakout board terminal marked “3V3” is an output of the built-in power supply. DO NOT apply any power on that terminal. GND is GND … it is common across the board. If using external components that require 5V directly from your power supply, make sure you understand how they are powered and what voltages they will be applying to the Imp pins.
Hi. Thank you for your reply.
So… It is safe to feed 9VDC to BAT ± connectors?
You’ll discover that any batteries, whether 9V cell or AA batteries won’t last long unless you use the Imp sleep functions to conserve power. That’s a different topic that you can find in the documentation.
Yes. On the April board you can connect 9V supply to the battery +/- pads. You can also connect it directly to the VIN/GND how ever these pins are not reverse voltage protected so if you plug in the battery (or even touch the pads) backwards then you will damage the April and probably the imp. Additionally, if you plug in USB when you the battery on the VIN pin then you could short USB to 9V which could be very bad for your USB host. When you use the battery pads you can’t short VBAT to VUSB so you don’t have to worry.
The determination of the power supply voltage should be made based on the external devices or components you will be using with the Imp. Example, if you have a bank of solid-state relays on a board and it takes 5-32 volts to turn them on/off, you would probably use a 12VDC supply to power the April board and the solid-state relays. Because there should not be 12VDC on the April pins, you would need to add some transistors or some optical-isolators to handle the solid state relays. Always keep the April board pins isolated from any voltage above 3.3V
During construction and testing, remove the imp from the April board and test all voltages before you slide it back in. With a breadboard, it’s easy to accidentally put a 5V or 12V wire directly on an imp pin.
I speak from experience … [sigh]