Alright, let me tell you about this thing I was messing with recently, something related to a component I picked up that just said “hung wei” on it. No brand, nothing else. Classic cheap stuff from online, you know the type.
Getting Started
So, I had this idea for a little project, nothing fancy, just monitoring the temperature in my garage workshop. It gets pretty extreme in there, summer and winter. I thought, easy peasy, grab a sensor, hook it up to a little board I had lying around, maybe an ESP8266 or something similar.
I went online hunting for parts. Didn’t want to spend much, ’cause it was just a garage monitor, right? Found this super cheap temperature and humidity sensor. The listing barely had any info, just some basic specs and a picture. The chip itself, when it arrived, had “hung wei” faintly printed on it. No datasheet link, no library mentioned, just the sensor soldered onto a tiny board.
Trying to Make it Work
First thing, I got my soldering iron out. The pins were tiny, but manageable. I hooked up the power, ground, and the data line to my ESP board. Standard stuff, I thought. VCC to 3.3V, GND to GND, Data to one of the GPIO pins.
Then came the software part. This is where the “fun” began. No documentation. Zero. Zilch. I started guessing. Is it like a DHT11? A DHT22? Maybe an SHT series sensor? I tried a few common libraries I had used before.
- Fired up the Arduino IDE.
- Loaded the standard DHT library. Didn’t work. Just got errors, `NaN` (Not a Number) readings.
- Checked my wiring. Re-checked it. Seemed okay.
- Tried pulling the data pin high with a resistor, like some sensors need. Nope.
- Switched GPIO pins on the ESP board. Still nothing.
- Okay, maybe it’s not a DHT type. I searched online for “hung wei sensor”. Found a couple of forum posts, people asking the same questions. No real answers, just more confusion. Some suggested it might be a clone of something else, but nobody knew for sure.
I spent a good couple of hours just swapping libraries, changing parameters, trying different I2C addresses just in case it was an I2C device mislabeled (it only had 3 pins besides power/ground, so unlikely, but I was getting desperate).
Hitting a Wall
After trying maybe five or six different sensor libraries, I was getting garbage data at best. Sometimes it would read a temperature like -40 C or +85 C (the extremes of typical sensors) when it was clearly room temperature. Humidity was often stuck at 0% or 99%.
It was incredibly frustrating. Here’s this tiny little component, probably cost less than a dollar to make, and it’s eating up my whole afternoon because there’s absolutely no information on how to use it properly. It’s supposed to be simple, right? Read a value. That’s it.
I even tried connecting it to a different microcontroller board, thinking maybe it was an issue with the ESP. Same result. Just junk data or flat-out errors.
The Outcome
In the end, I gave up on the “hung wei” sensor. I just couldn’t reliably get anything sensible out of it. Maybe the sensor itself was faulty, or maybe it uses some weird, undocumented protocol. Who knows?
I tossed it back into my parts bin. Maybe I’ll try messing with it again someday if I’m really bored, but honestly, probably not. Time is worth more than the couple of bucks I saved.
My takeaway? Sometimes, saving a dollar or two on cheap, undocumented components just isn’t worth the headache. I ended up ordering a sensor from a known brand, one with actual datasheets and libraries. Cost a bit more, but it worked literally five minutes after I hooked it up. Lesson learned, I guess. Stick to stuff where you can actually find out how it works.
