johanmoberg

Guys if you're not 100% on your electronics and battery knowledge, I would advise from building your own battery packs. The equipment and time required to construct safe and high quality packs is usually not worth it unless you really want to learn and construct many packs the coming years. Yes, a brand new pack and charger is much more expensive but it will also last much longer and you wont burn your house down (a real lithium fire extinguisher is around €600). You will find many guides showing you that it's easy, fast and cheap but that's mostly because its done in an unsafe way and resulting in poor quality packs. I don't want to bash the author but there are many things in this tutorial you should NOT do.1. Using old cells with under 2 V charge is both unsafe and a waste of time. Whe…

Guys if you're not 100% on your electronics and battery knowledge, I would advise from building your own battery packs. The equipment and time required to construct safe and high quality packs is usually not worth it unless you really want to learn and construct many packs the coming years. Yes, a brand new pack and charger is much more expensive but it will also last much longer and you wont burn your house down (a real lithium fire extinguisher is around €600). You will find many guides showing you that it's easy, fast and cheap but that's mostly because its done in an unsafe way and resulting in poor quality packs. I don't want to bash the author but there are many things in this tutorial you should NOT do.1. Using old cells with under 2 V charge is both unsafe and a waste of time. When discharged below 3 V chemicals build up in the battery permanently increasing resistance and the cells can become unstable and prone to short circuit, overheating and fire. DONT USE!! Best case you have a "working" cell with 30% of its original capacity. Yes, it will charge to 4.2V but will go flat very quickly and become hot during discharge. 2. Never use a BMS with higher current rating than the batteries(!!!). Here you have two 4A batteries in parallel, max current is 8A (for brand new functioning batteries which this is not). This BMS wont cut the current until 20A (rated for 10A continuous current, 20A cutoff). When you use bad batteries they wont discharge evenly, in this case you can have one cell discharging 15A. Discharging a battery several times its listed discharge current is a great way to ignite your battery pack.3. When designing a BMS, the best practice is two fuses, one where the IC will cut the current (well before reaching battery max current) but also a second, conventional fuse in case the IC doesn't work. Cheapest China BMS's skip this to cut cost. You also need to verify that the protection really works as intended before using the pack. 4. A proper BMS has a temp sensor for the battery, in case the battery goes above say 70C it turns off. A black pack laying out in the sun in the summer can reach 60C, even without being used. Too hot batteries leads to thermal runaway and battery fire occurs.5. Packs needs to be spot welded, yes many people online says you can solder them if you're just fast, don't. Both dangerous and the heat deteriorates your cell. You can buy good solderless cell holders if you don't want to buy a spot welder.6. Parallel cells needs to be balanced before connected, if one cell is 4v and second one is 3.2 v, you basically charge one battery with an uncontrolled high current.7. Don't work on fully charged batteries, that one mistake will do much more damage.8. Placing a pack you're working on piece of wire, screw, wedding ring etc etc will effectively make your pack into a welder.9. Cheap china BMS is you get what you pay for. You are going to store this high energy battery in your home with the lowest quality safety system.10. How is the pack exterior designed? Can in vent gas if the cells overheat? Does it protect against a spilled cup of coffee or condensation? 11. Packs should to connect to BMS with a connector. First fix connector, then solder wires to the pack. You don't want to solder wires straight on the BMS which are live, if you drop one cable and it accidentally touches another nearby wire you have a short circuit.As I said earlier, if you want to learn how to build packs, go ahead its a lot of fun, but only do once you really understand how everything works. There are two kinds of people who thinks battery packs are simple, those who are experts and those who are amateurs.

Hmm depending on what micro controller you have you should either use Serial or Serial1. Since you have Micro pro, Serial1 should work. My guess is you're compiling for the wrong board (perhaps Arduino uno?). Check Tools->Boards menu in Arduino IDE.

No problem! Good luck!

Thank you for sharing! The build looks super nice! I originally made mine as a gift but since I have moved now I have this problem myself. I will build one for myself as soon as my project queue has an empty spot and I'll implement your solution with gravity switch instead of the original. Great job!

Hi! If you have code that rotates the motor that works, just replace that section of the program with that or just check how the two differs.

The current limitation is important to mention for safety. Don't overload these batteries. In the picture he runs a big motor which surely must have +5A startup current, these batteries were never designed for that type of application. The big difference between the 2200 mAh battery pack in the picture ($13) and this is that battery can output 55 A of current (77 A peak) while this should output around 0.6 A. For low power application this is a great solution but not for larger current applications. The battery may become very hot and pop/burn. Just be careful with Li-ion batteries is all I'm saying.

Hi! Its just at the end, near Step 6. Good luck!

Hmm ok, is the library for alarms correctly installed? Is the sketch you're running the original or hade you modified it? Try running some example sketch included with the library just to verify the library works.

Nice and useful thing! Nice work with the inputs and lcd, fast and clear to set up! Add the option to strip the ends and I'd buy it! :)

Probably your motor inducing back-EMF and the display module/Arduino is shorted and resets.Whenever something resets its usually a bad sign :)Try adding a diode in parallel with the motor and the problem should be solved.

Beutiful!

Very nice workmanship and tasteful design! Would buy any day!

This is great project! Nice PCB and the complete robot looks great! How are the results, I can imagine the hardest part will be to distinguish weed? Perhaps you will need some machine learning and a couple of hundreds of weeds for practice? Voted for you, hopefully some of the more intricate projects of this site should get more recognition in the future.

Hej Sorry för sent svar! Ja ibland kör jag dem på full speed, kör dom på samma strömkälla som ledsen som jag pwm dimmar. Men vad konstigt att de låter så mkt, det gör inte mina. Eller ibland när någon fläkt kommer i "otakt" kan den börja låta rejält. Låter alla lika mycket? Har du testat någon annan strömkälla? Ibland kan det ju bli nån transient vid uppstarten som gör att den kommer i "otakt".

En klutt kylpasta och tryckte dit den ordentligt, därefter en droppe klister i varje hörn så den satt fast.

I don't understand how you can control on/off of the driver with that connection? The driver would always be ON regardless of what you set pin 16 to(?) but if set to LOW, it would short circuit,set off the internal fuse of the uC and both bt transceiver and step motor driver would experience a fast voltage drop and reset. If I were you I would start without using pin 16, and later if everything works, connect pin 16 to the sleep pin instead. But if I understand you correctly; everything works if you only change the software? If that is the case I would try; 1) Remove pin 16 connection. 2) Change the delay between the motor steps in the code – Try increasing the time by 100-500%. If it works you should get slow speed. Then reduce this timing to optimize motor.3) Add some decoupling …

I don't understand how you can control on/off of the driver with that connection? The driver would always be ON regardless of what you set pin 16 to(?) but if set to LOW, it would short circuit,set off the internal fuse of the uC and both bt transceiver and step motor driver would experience a fast voltage drop and reset. If I were you I would start without using pin 16, and later if everything works, connect pin 16 to the sleep pin instead. But if I understand you correctly; everything works if you only change the software? If that is the case I would try; 1) Remove pin 16 connection. 2) Change the delay between the motor steps in the code – Try increasing the time by 100-500%. If it works you should get slow speed. Then reduce this timing to optimize motor.3) Add some decoupling capacitors to this circuit to avoid any wired transient behaviors, especially if you are using a high impedance power source. Let me know how it goes! Best of luck!

Of course! Best of luck!

Tack! :)

Hi! Yepp, I have one. The problem for me is that I sleep quite close to the grow so even though it was one of the more silent ones, it was too loud. And I was quite skeptical about how much oxygen a couple of herb plant actually need, everybody seem to advocate "more is more" but no one really seem to know the actual oxygen consumption required. I have not noted any reduction in grow speed since I swapped to the small pump. But if I were to grow larger plants I would go back to the bubbler.

Thanks! Hehe ok! :D

Tackar :D

Yepp! Anything particular you want to know beside this tutorial? I think the best and easiest way is to buy the IKEA fitting (http://www.ikea.com/se/sv/catalog/products/90319065/) and just put your own grow LEDS inside it. I will probably upgrade my grow with automatic EC and PH reading during the winter so check back in some time!

Hehe I've started ordering online from them to avoid buying to much :DThanks and good luck if you build it later!

Ok great! Thank you!

Thank you! Aha the interrupt is just "left overs" i think. The receiver never sleep so it doesn't need the interrupt. At first I was doing one code for both devices, but it got so long i decided to split it up. The push button is not used, it's only the capacitance button which uses pin 2 and 1. Initially it was supposed to be a push button which later on were swapped to the cap. button. Sorry for any confusion. Good luck!

Or you could just buy something like this http://www.conrad.com/ce/en/product/275168/Brass-Steel-Worm-gear-set-Reely-Module-Type-075-No-of-teeth-60

Hi, sorry for the late response, missed your comment! Yeah Vcc and Vdd are the same, its just the A4988 sheet that decided to call it Vdd.

Thank you! If you want it to stop before being completely rolled down, I would suggest using a worm gear. They are self locking and would hold the load when the motor is powered down. You could grab and modify something like this for your purpose (not my design) http://www.thingiverse.com/thing:28126Good luck!

Aha no transistor is used for the receiver, its only to save battery for the sender. The HC-12 ground is just connected to ground on the reciever.

Perhaps Jody thought the pads were 220v? Thats what's nearly gave me an heart attack while browsing :D But perhaps attach the hv cable firmly to the board so it can take some force without being pulled out. Also maybe put the HV board in a splash proof/grounded box within the box.

Yes, you can find the stl files under step 7! I can share the PCBs but i would'nt recomend using them for this project. I made these boards to use in 2-3 different projects so some "special" (read not good) solutions are required to get them to work with this specific one. The other project required 6 boards so i made them to suit that project. Since this project only requires 2 boards i think it will be faster for you just using protoboards. Good luck!

Hi! I use the labels instead of "wire"( I think it gets less messy). Just add wire between the connections with the same name and you should be good to go!

Thank you for sharing, I love solutions that aren't more complicated than they need to be! I made this to my parents and their mailbox isn't visible until you're standing next to it (hedges and turns).

No not really, except from testing the transmitters at the mailbox to make sure it worked before getting into the details. Can't really say if it´ll work for you as obstacles will reduce the range dramatically. What I can say though is the placement of the antennas makes a big difference, in a well insulated house and behind several thick walls is not a good idea. I haven't noticed any differences during different types of weather but that may very well affect the range.

If you add a small directional antenna, point it out toward the street and try to bounce the signal off nearby buildings up to your window it might work. I would suggest just purchasing two HC-12 and test with them first before buying anything else. The parts are easy to find, for HC-12 i recommend 5 pack on; http://www.banggood.com/5Pcs-HC-12-433-SI4463-Wireless-Serial-Module-Remote-1000M-With-Antenna-p-980288.html

Good project! Impressive work from 14 y/o, keep it up! Btw if you use the analog pins and analog write you can change the speed of the motor as well!

Aha see step 5, the magnet is attached to the mailbox "door" so when it´s opened it passes the reed switch.

Thank you!

Thank you! Nope, it's just the signal to the motor(created by the step driver) and any type of cable would work. The motor has two electromagnets inside so it needs 4 cables.

Well the 200 mA is for constant draw and very little airflow (only 1.4 W heat). I guess it's a matter of taste how you solve it, I'd say the best solution is to just read the sensor in 30 min intervals (+ life span of sensor). Then you´re about 60-100 mA average current plus it´s located next to the 120 mm fans.

Great design and well laid out instructable. Suggestions for improvement; 1. Remove both relays and use a single transistor with pwm from the arduino to change speed seamless. 2. Remove the vregs, you can input 12 v to the nano and use it´s own vreg to output 5 v. This should reduce the size of the board a lot + cheaper. Good job!