hello everyone. I am lightly versed in arduino and electronics. understand flip flop circuits, logic gates etc. what is challenging is I would like to use my arduino to turn on / latch on a component then go back to sleep. later send a signal to turn it off. I have found tons of breadboard experiments with LED's and momentary switches but the LED's are also powered by the arduino. I want the arduino to activate a latch/flip flop on another entirely different analog circuit, though they both run on the same power supply. in others the arduino wakes up, turns on a component, goes back to deep sleep and does absolutely nothing but snore till it is time to turn the component off. also it is battery operated and power consumption is a major major factor.
Yes, correct, a RTC, ON @ 9:00 pm. Then OFF again at 6:00 am. 7 days a week. Latch circuit on - latch circuit off. Analog flip flop circuit triggered by arduino.
When you write an Arduino pin HIGH the pin will be driven HIGH. If you connect nothing (or CMOS input) to it no current will be consumed. If you connect a LED to it the same current will be used as if you connected the LED to 5V directly. The Arduino will take (nearly) nothing for itself.
Maybe you need to just make the arduino go to sleep. And then, when it wakes up, get the arduino to read the output state of the flip-flop. This is so that the arduino knows whether or not the flip-flop is in the expected state for that particular time. And after this check is done, and everything looks ok..... then get the arduino to change the state of the flip-flop (ie. toggle it by sending a single pulse to the trigger input of a toggle flip-flop). And then go back to sleep again.
Which analog circuit would you recommend? Here's one where I replace the momentary push button s1 with a transistors a switch. The Arduino signal goes through a resistor to the base of the transistor. It only takes a short signal. To flip or flop On another board someone said it was too complicated. But it only takes one pin of the arduino and a short signal to turn it on or off. Your thoughts.
Which analog circuit would you recommend? Here's one where I replace the momentary push button s1 with a transistors a switch. The Arduino signal goes through a resistor to the base of the transistor. It only takes a short signal. To flip or flop On another board someone said it was too complicated. But it only takes one pin of the arduino and a short signal to turn it on or off. Your thoughts.
I don't understand your goal. Do you want to use Arduino or not? If you are using Arduino such as Arduino Uno you cannot make low current consumption - you there is too many power hungry parts such as LDO, USB/TTL converter, power LED etc. If you use modified board for minimal consumption or standalone ATMega I don't see any reason why to use external latch to power the load - you can simply turn it on/off via the "Arduino". If you want to use the Arduino to program the RTC and then remove Arduino and let it run alone you can use a flip flop or similar IC to do what you want. But if you want to get help with choosing the right IC, you must provide much more details about your project. What RTC you plan to use, how it will work (what signals it will generate)...
Goal. Have the arduino wake up. Turn on the transistor that will take the place of S1. That means Send a current to the base of the transistor which will turn the transistor on. Closing the circuit as if you were pushing the S1 momentary switch. Now my circuit is on. Later the arduino wakes up sends a current to the base again, closing the circuit and turns the circuit off. It then goes back to sleep.
If you look at the circuit. 1 push of S1 turns it ON. another push of S1 turns it off.
The Arduino will push the button whenever I tell it to. Because all it needs to do is send a current to the base of the transistor which replaces switch one. Momentarily closing the switch as if someone actually push the button.
I can't be there to push the button. This is not about RTC's or my Arduino. The + side of the switch will be the collector the other side the emitter. The BASE current will be provided by the arduino.
When the Arduino goes to Sleep the outputs stay as you last wrote them, either High, driving current to Vcc, or Low, sinking current to Gnd. Inputs with internal pullup resistors will be High, pulled to Vcc by 30K to 50K of resistance. Inputs without pullups enabled will float.
RTC may be used to wake up (or turn) on Arduino. There is little reason to add the 555 - Arduino may drive the transistor on your picture directly. If you use it properly it will use less current because 555 itself is more power hungry than sleeping Arduino (modified for low power consumption)
Smajdalg. Thank you sir. I "can" eliminate the 555. That's good to know. Can you clarify wake up/turn on. My project is battery powered. It runs 24/7. 16 hours a day the arduino isn't needed for anything at all. Though it only uses a tiny bit of power when in a deep sleep. That's still 16 hours of "a tiny bit" X 180 days = 2880 hours of a "tiny bit" did you mean "on" or "wake up"? Thanx
If you are interested in low power consumption the Arduino must modified (removed all power hungry components) - better way is to use full Arduino for debugging and then switch to standalone chip. If you implement sleep correctly the "tiny bit" will be very small - (much) less than self discharge of batteries.
