Agree! The LM35 is great for teaching people about the A/D converter. Its linear response of 10mv/degree is great for showing how the A/D count relates to temperature and to the actual voltage on the pin. It's also helpful to show how changing the reference voltage, which by default is often Vcc, affects A/D readings. The simple math to convert A/D readings to a temperature value really cements people's understanding of these concepts.
Fun stuff. My mom has been wanting something to measure the temperature of her house when she travels. I may have to dig through my bins and work something up. Thanks for sharing.
A while back I 'instrumented' my waste-water heat exchanger (google GFX gravity film heat exchanger) with one-wire sensors. Four sensors for potable-water in/out and waste-water in/out. Kind of freaked kids out because after reviewing the logs, I could tell that someone got up at 1:40AM and flushed a toilet one night. lol But seriously, these sort of sensors are great for monitoring whatever you like around the house. I'm thinking about putting some thermocouples on my furnace and hot-water heater flue so I can monitor those next. Thanks for sharing your information.
I have been using the aht20/bmp280 combo boards. They work pretty good, super fast response and like 2 bucks a peice for temp hum and pressure. Better than 15 for a bme280
For a k type thermocouple you also need cold junction compensation to get an accurate reading. I expect that the chip had that built in? Just had a quick look at the max6672 and it does have the cold junction compensation built in. You also need to remember that if you extend the wires if there is dissimilar metals extra thermal voltages will be added to your signal.
if the extend the wires at the end, with say copper wire, the place you spliced it becomes the cold junction. But I think if you instead extend the wires in the middle the extra junctions cancel out
@@fuzzy1dk Could be, I’ve only used extension leads where the same material is used, or bought the thermocouples with extra long wires so no need to extend just cut to length.
@@fuzzy1dk That's right. Every point where there are dissimilar metals forms a junction. But as you go around the 'loop' from sensor to readout point, many of them cancel out. Depending just WHAT you're reading, cold junction compensation might not be too important. For example, if measuring flame temperature of burner or exhaust of an engine, having the cold junction rise/fall by 20 degrees or so will throw your reading off by 20 degrees, but in the grand scheme of things, it might not matter when reading something over 2000, vs 2020.
It's funny how many there are. For 3d printers there's like a page worth of them listed in the marlin source file. I'm waiting for a bosch BNO055 imu sensor. It cost more than I've ever paid for any one sensor. Adafruit charge over 100cad for their's on Amazon. I slowboated it for around 45 lol
You gotta be careful with some of those sensors that have fiberglass protecting the wires. I got some before where the fiberglass was breaking and the pain that resulted from not noticing and getting the fibers in my hand was brutal, and took days to go away. You could barely tell it was breaking other than the pain that resulted after handling.
You technically don't even need a sensor, just a voltage divider made from two resistors (and a diode for over-voltage protection if desired) on an analog pin.
The trinket is based on the ATTINY85, which is a pretty capable little board - there's an ATTINY85 running the scrolling text sign you see on my workbench.
Adafruit, dude you need to switch to circuit python and ditch that awful ide. VsCode PyCharm... once you get the repl working you can test the lines of code you want to run (yes on the device) without having to build and export. Watch Scott Hanselman "Hacking an AdaFruit M4 Matrix Display" for someone who tried it for the first time. But thanks you reminded me i have a bunch of one wire temp sensors that i had in a long string and will work great with the esp32 where ever i have one.
Well, the DHT20 is what I ordered. I keep trying to find videos showing its usage but it's always a different version of the sensor. I'm a newb and I just ordered a RaspPi Pico, DHT20, and an OLED for experimentation heh
@@3nertia I may be misremembering, but that's the version that I got and I don't think there was any difference in its use, I think it probably just had a wider measuring range.