Hi, any ideas to make this work? I wanted to use this 12v temp/hum unit to send readings to my house from the gas tank with a new 0-90 ohm dial. is it possible.
Buy a proper device to make the readings safely.
It’s a gas tank! You must follow some regulations.
Hi, unfortunately & like many they only cater for small bottles/tanks. But it was worth a try.
Chris
I think that T/H sensor is digital and so it won’t work with simply cutting the wire. Do you have an always on computer, such as an iHost or Home Assistant setup? If you do I would just use a cheap seeed studio XIAO ESP32 with wifi that can be programmed using the free and easy Arduino software and get it to send MQTT messages. An alternative would be to buy a device like that, open it and put something like Tasmota on it. Tasmota would facilitate internet access aswell as MQTT thereby bypassing the need for an always on computer.
If I understand your picture correctly the sensor you have needs 12v, which is out of the range of an ESP32, so you could either step down the voltage or use a wifi version of an Arduino microcontroller (all my Arduino microcontrollers are old and lack wifi. The ESP 32 mostly has it built in, but they have a VREF input so you could use that sensor and the 12V supply you already have planned to)
Hi, thanks for the ideas. They seem to use R3D Hall Effect sensors to pick up the magnetic feed from the dial. So, it would be converting this signal/voltage into somthing readable.
Might be worth looking into the details of how that exact switch works but my sensors that look like that have been digital and the standard Sonoff one that looks like that is digital. Sounds like you need an analogue one in, which you could digitise with a ADC. I can’t see why that is dangerous as you will see the dial as you set up the device and unless you store the tank in the sun or heat it up I can’t see why the pressure would go up. An error would be misleading you into thinking the pressure is higher than the reality, which is not dangerous, unless you count being cold as dangerous.
The gas tank gauge works the same as a cars gauge.There is an arm in the tank with a float attached & when the float goes up & down it turns a magnet 360deg under a brass sealed holder. “remembering gas turns to liquid under pressure” Then you often just have a dial with a metal indicator that picks up on the magnet & turns. “saves having any electrical contact” But now they make dials the same but fitted with a pick up to send a signal/reading.