is 1-wire temperature sensor from Maxim. This has to be worlds most know digital temperature sensor, very cheap on Ebay. Has up to 12-bit resolution. You can get sensor only or on PCB or in metal case, which should be waterproof.

Measures temperatures from -55°C to +125°C.

The 18b20 is ±±0.5 (typical) from -10°C to +85°C. And ±2°C (maximum) from -55°C to +125°C. Not bad for such simple and cheap sensor.

I has user-selectable measurement resolution from 9 to 12-bits. At 12-bits resulution it takes 750mS to take sample. If sketches made by users, this is even faster, below 700mS.

• Operating Voltage Range: 3V to 5.5V
• Standby Current: 750 nA (typical)

Biggest problem back in the day was, library from Dallas, now Maxim, was so called blocking. This means, once you triggered reading of temperature, your code did nothing else in the mean time. That could be up to 750mS, which is a lot. Different people took a look at what is doing that, changed library (or sketch) to a point, where they could do other stuff wile waiting for teamperature reading to be returend. Today, this seems to be fixed since we have .setWaitForConversion(false). Have a play with this kinda code, to see how it behaves now and how it did before this was possible.

Here we also have scanner for DS sevices, but since this is 1-wire bus, it doesn't work the same. You can run get address sketch. In it, you define to which pin you have your DS's connected, in this example it is pin 6. #define SENSOR_PIN 6

Some sketches are such, that you need to know addresses of your sensors, others can find them first and then use them. But you can make all of them do that, one you know how. I'll have those kinda sketches also here.

From it, you will get all sensors that are connected to this bus, it will look something like this (it will start with 0x28,... this are my 3 sensors):

Looking for 1-Wire devices...

Found '1-Wire' device with address: 0x28, 0x88, 0x01, 0x28, 0x02, 0x00, 0x00, 0xBB
Found '1-Wire' device with address: 0x28, 0x88, 0x25, 0xE3, 0x05, 0x00, 0x00, 0x8B
Found '1-Wire' device with address: 0x28, 0x6D, 0x35, 0xE3, 0x05, 0x00, 0x00, 0x35

If you use find_and_display sketch, you'll get output similar to this:

Locating devices...Found 3 devices.
Parasite power is: OFF
Device 0 Address: 28880128020000BB
Device 1 Address: 288825E30500008B
Device 2 Address: 286D35E305000035
20.00 20.94 21.00

Anyway, other sketches are better optimized for size it takes in flash, so use which one you like more for project you're doing.


LowPowerLab ColinR_1

LowPowerLab ColinR_2


LowPowerLab ChemE NROO which also needs you to change original .h and .cpp files (NROO = No Resistor and Object Oriented) (uses 686 bytes of flash)


DS18B20 visits:

Application Note on bridging audio amplifiers

A discussion on bridging audio amplifier circuits like LM3886. Includes a schematic to drive a matched pair of amplifiers in a bridged configuration, power supply considerations for LM3886 and TDA1514 power amplifier circuits-especially in bridged pairs.

Application Note on parallel-bridging LM3886 audio amplifiers

How to make it loud - real loud. (230 watts rms into 8 ohms without clipping from 4 ICs. How to match LM3886s for parallel operation, then bridge the matched parallel banks. If you are not familiar with bridging amplifiers (BTL configuration), read the Application Note on bridging listed left in article Application Note on bridging audio amplifiers.

My first car audio system My second car audio system My third car audio system

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