Wireless Remote Propane Tank Level Gauge

[PeterN]

Hi PeterN
I found this old D1 Mini Pro in my junk box. I wanted an external antenna so it fit the bill. The ceramic ant. had been removed, which back in the day was an option vs removing the resistor. I tried several antennas, and low and behold, the RC aircraft antenna worked as good as any! (according to Vistumbler)

Thanks
Zim

Hi Zim, I tend to say: Never change a running system , but ...
The signal strength seems to be sufficient for your purposes or distance ... but at the moment there is obviously NO antenna connected to the output of the ESP8266, because the bridge would still have to establish the connection to the center contact of the antenna socket. At the moment there is certainly only a weak capacitive coupling, which also explains why your connected external antennas could not generate any serious differences.
Have a look here:

[Zim]

You may be too old to walk through the snow, but you demonstrate a mind that many young people would already like to program code. And to share it.

Rummaging through my drawers, I find 3 modules with HMC5883L. One, labeled GY-271 looks identical to the one in your photo.
I don't have a propane tank, but I can try to reproduce your schematics in case I can help you as a beta-tester.

Thanks Fernando
Thanks for the support you showed with my first kick at the cat on compasses. They are a nightmare for newbies like me.

Zim

[Zim]

Hi PeterN
I found this old D1 Mini Pro in my junk box. I wanted an external antenna so it fit the bill. The ceramic ant. had been removed, which back in the day was an option vs removing the resistor. I tried several antennas, and low and behold, the RC aircraft antenna worked as good as any! (according to Vistumbler)

Thanks
Zim

Hi Zim, I tend to say: Never change a running system , but ...
The signal strength seems to be sufficient for your purposes or distance ... but at the moment there is obviously NO antenna connected to the output of the ESP8266, because the bridge would still have to establish the connection to the center contact of the antenna socket. At the moment there is certainly only a weak capacitive coupling, which also explains why your connected external antennas could not generate any serious differences.
Have a look here:

PeterN
You are so right!
Thanks so much for the good catch! And yet the dam thing still went through 4 walls and 75'. 83% signal. I can't wait to retest!

Thanks
Zim

[BeanieBots]

It should be quite easy to get > 6 months from a lantern battery even at hourly transmissions.
Don't know about your compass module but the ESP will run quite happily down to <2v, so 2 * D cell would be more than plenty.
Not sure why you want the timer device. What is wrong with wake-from-sleep function?

[Zim]

It should be quite easy to get > 6 months from a lantern battery even at hourly transmissions.
Don't know about your compass module but the ESP will run quite happily down to <2v, so 2 * D cell would be more than plenty.
Not sure why you want the timer device. What is wrong with wake-from-sleep function?

I plan on retrying the "wake from sleep" once I get the bare-bones module assembled. I tried the "wake from sleep" with a ESP32 DEVkit module and found the sleep current higher than desired. I'm hoping that removing the serial chip, regulator and led will reduce draw when asleep. The timer is a "if all else fails" solution. I am paranoid about battery performance at -50. We do see that from time to time.

I don't have much experience with battery life, so correct me if I'm wrong!

Zim

[BeanieBots]

The devkit will draw a significant current even during sleep as you have already found out.
I've only played with 8266 modules in their raw state so have no real-life comparison with the ESP32.
I think a major issue will be the requirements of the compass module.
Could you use a naked ESP8266 such as the 12F? (cheaper and lower current)
Will it run off 3v or does it require 5v?
Can an IO pin supply the required current or will it require a transistor?
Lithium batteries don't like the cold. Fine down to -5 but again, I'm afraid I have no hands on experience at -50.
You are in for a fun project and will have the pleasure of making new discoveries.
Please post your findings so we can all learn.
More than happy to help where I can but even my deepfreeze only goes down to -22 so you're on your own at -50.
Good luck!

[Electroguard]

Hi Zim, thankfully I have no experience of your sort of temperatures, but here's some thoughts for whatever they're worth.
No matter how cold it gets, DC is essential to power your circuit - so the way I see it, you either need it to survive on minimal pwr rations for as long as possible, or you can provide it with an additional pwr stockpile.

If you used something like a solar power bank to supplement your circuit battery supply, it would certainly make it last longer.
You are probably far enough north that you can angle the solar panel to still catch available daylight while allowing melt to run off.
With plenty of pwr available, perhaps you might even rig up some sort of a servo screen wiper (like you see on some CCTV cameras).

solarpwrbank.jpg

Alternatively, you could use an old vehicle 12v battery as a supplementary supply... any battery than can survive in a vehicle engine bay should be ok in a cosy purpose-built little 'kennel'. Or perhaps you can pick up a 12v supply from a nearby parked vehicle.

Even when 'flat', or with duff cells, your little circuit aint gonna drain a vehicle battery any time soon.

dcpwr.jpg

And a Wemos DC Power shield only needs about 7v or more to keep providing supplementary power to your circuit.
Plus, if your circuit doesn't need to survive on minimal pwr rations, you could afford to permanently keep monitoring the supply voltage to give warning if the battery voltage was dropping a bit low. And no fear of it going into a deep sleep 'coma'.
You could even permanently monitor things like temperature and lux... no shortage of ADCs if using an esp32.
By using a doubler (or trebler shield to give esp32 shoulder room) the DC Power shield would not obstruct the wifi signal.
And Wemos shield are available dirt cheap.

[Zim]

Please post your findings so we can all learn.
More than happy to help where I can but even my deepfreeze only goes down to -22 so you're on your own at -50.
Good luck!

I sure will!
Thanks

[Zim]

Hi Zim, I tend to say: Never change a running system , but ...
The signal strength seems to be sufficient for your purposes or distance ... but at the moment there is obviously NO antenna connected to the output of the ESP8266, because the bridge would still have to establish the connection to the center contact of the antenna socket. At the moment there is certainly only a weak capacitive coupling, which also explains why your connected external antennas could not generate any serious differences.

Thanks PeterN
signal went from 83% to 86% !

Zim

[Zim]

Could you use a naked ESP8266 such as the 12F? (cheaper and lower current)
Will it run off 3v or does it require 5v?
Can an IO pin supply the required current or will it require a transistor?
Lithium batteries don't like the cold. Fine down to -5 but again, I'm afraid I have no hands on experience at -50.
You are in for a fun project and will have the pleasure of making new discoveries.
Please post your findings so we can all learn.
More than happy to help where I can but even my deepfreeze only goes down to -22 so you're on your own at -50.
Good luck!

Hi BeanieBots
Our temperature dropped to -44 F. Propane furnace quit. (low tank pressure) We are prepared for it though...

The IO pin will supply enough current for the compass module without a trans. After building a bare bones ESP32s, I got the deep sleep current down to 9uA. The C005 (although very neat) draws around 400uA, so the ESP32's deep sleep function wins for me. I used a HT7833 reg. I was getting random brownout errors until I added a 1000uf across the 3.3v. Now its rock stable. I will post a pic of the board and module when I finish. Really cheap at Aliexpress...

Cheers!
Zim