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DIY Data logging weather station under $15
One thing I'm finding is once the battery reaches the low voltage point and is discharged, the program does not stop. When the cell voltage recovers, the program will reconnect the load resistor and continue to recycle. If left unattended, it may damage the battery. I would like to see the program disconnect the load and stop.
Answered my own question. Moserial for Ubuntu works very well to log data from Arduino.
Is there a way to save the serial data into a file with Ubuntu?
I'm ready to make one. Will be using a Arduino Uno Relay board I designed. Slight mod to the program will be required. With a relay instead of a mosfet, this completely disconnects the battery after discharge. I can even eliminate A1 adc channel, If I can understand how the program works. This will be a fun project.
I like it. Will probably make it soon. I have some 14500 lithiums to test. Are you working on V 2.0 yet?
This looks like a nice project to test lithium cells. I would like to see it disconnect the battery at a higher voltage such as at 2.7 so as not to damage the cell. Also I would probably change the discharge current to 250 milliamp for testing 14500 cells. Especially when testing low capacity "fake cells".
Can I use any of the analog pins (A0-A5) to connect a servo?
Oops, 14500 cells. My mistake. One thing I wish is that Instrucables would allow the author to make edits on their own posts.
Some people have used a small neo-magnet disc as a spacer to stick to the battery.
The Utiltech flashlight I use an example, will start to dim around 2.7 volts and become obvious charging is needed. I don't think it has any voltage conversion circuity inside. Some flashlights can still be bright at really low voltages that could be a danger to the cell. So a protected cell is a good idea. I just charge my cell every few weeks to keep it up.
Great idea using a 3D printer. I you got one use it.
Did you have to modify the flashlight to fit the 18650?
The lithium cell shown is a common lithium ion 14500 Ultrafire that charges at 4.2 volts. The 18650 you mentioned will not fit the flashlight and can't be used. Only use a 14500 size cell. When in use, the cell voltage will be about 4 volts.
Convert 3-AAA Flashlite to ...View Instructable »
Its working now. Making an instructable.
I was able to find Ultrasonic.h at Github. When you compile, the IDE will say it can't find WProgram.h. The only way to fix that error is go into Ultrasonic.h and Ultrasonic.cpp and change WProgram.h to Arduino.h. Make the edit and save. After that it will work.
To make it work, we need the library Ultrasonic.h. Where might I get that?
Can it be made to work on both 800 and 1900 mhz by making one of the dipole pairs larger?
That's correct, Sorry for any confusion.
The protocol is different with iOS. I got s low cost Android tablet to experiment with.
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