pi5!

Is your calendar stuck on September? :-P

A nice evolution of the Pi.

I would rather see a Pi that will run for 7 days from 4xAA.

I accept most folk want faster and faster still, but I would like battery powered and long time running for my wild-life cameras.

I am building one that I hope will run for a year from 3xAA

Cameras eat watts. Invest in serious LIPO packs or lead acid batteries

A truly impressive goal, given that some of the more seriously power-efficient microcontrollers I can find draw 2.4mA when in operation, which would give you about 145 days of runtime on 3 2850mAh alkaline AA batteries. They claim that power consumption scales with clock rate, so if you halved the clock rate to 16MHz you'd get almost a year.

Interested to hear your plans.

john

Oh its very simple. I tried to do it old school with an analogue timer but couldn't get it done simply due to unavailability of low leakage large value capacitors so I looked at uber low current draw timers, but they were all surface mount and I cant do that technology due to old eyes and fingers, but I found a board that does exactly what I want made by sparkfun

The theory is the timer times out, the pico wakes up, measures oil level with a burst of ultrasonics. checks the battery level, connects to my wifi, shoves a small TCP/IP packet to the pi zero server and once it gets an 'Ack' flips a GPIO pin which goes to the timer board and shuts down the pico for an hour or so.

I reckon a minute an hour of about 100mA consumption so an average draw of around 1.6mA times 24x365 is 14Ah. Which isn't great, so I am hoping that it can read data and connect/send in less time than that . The big problem is the oil tank is remote and the existing wireless device can't do the range to a sensible place for the receiver, but I can put a wifi hotspot *almost* close enough. And up high if needs be.

It wouldn't be the end of the world if it just connected every 3-4 hours or every day - oil levels move slowly, but the largest preset delay the chipset will do is 2 hours. The main issue the pico has is sending wifi data, where it can spike (allegedly) to 150mA, but while running its not much more than 50mA. But then the ultrasonic transducer will take a bit to do its 'chirp'. So its all very unknown.

The current device often takes a day to respond to a recently filled tank. It runs off a 2032 lithium battery I think, button cell anyway. That lasts about 18 months

So its all a bit 'how long will the battery last' until I've built it, and that's why the voltage monitor is going in. I will probably set the server up to send me an email on either low battery or low oil!

I don't mind changing batteries twice a year if I have to, as long as I can do it before winter sets in!