I'm hacking a callbell to connect an ESP32 in order to send me a Telegram notification. The software side is OK but I'm having difficulty in detecting when the callbell goes off. When it is triggered, 5 LEDs flash. They are connected in parallel with +5V at the anode and via a 2K resistor into a pin on an unmarked IC.
Ideally, I'd solder a wire between the resistor and the IC to detect the falling edge but there is very little space. Between the LEDs and the resistor there is sufficient space to attach a lead but I can't make it trigger an interrupt. My question is, can I add my own 2K resistor between this lead and the GPIO pin?
circuit diagrams
Edit: managed to solder a lead between the resistor and the IC. Project deployed and works well. Thanks for your help
Yes you can. Just make sure your device has a common GND wit your ESP32. Also measure the voltage there and check the required resistor resistance..
EDIT: If I am right, this will connect GND to the digital pin, that should be pulled HIGH, then you can detect the GND.
Also connecting a transistor to switch 3.3V when gnd is given by the IC can be a good solution.
Related
On Adafruit there was an example on how to connect a ledstrip to an arduino, but it said "For longer strips requiring more than 1A, wire power directly to the strip, then run power and ground wires back to the Arduino." I didn't fully understand it so i made a sketch on circuits.io . Since there isn't a normal ledstrip in there i used a RGB to show my sketch, but i can't test it. So before i fry my arduino or ledstrip can someone explain if this is correct or if it needs to be changed? Also can i connect everything on a breadboard or not, since the higher voltage and amp.
https://i.gyazo.com/27e9a6527805b6e4e898a8f32f66de61.png
That would work.
I believe this is the same as this https://learn.adafruit.com/rgb-led-strips/usage
about the breadboard it really depends on the breadboard they can vary from cheap ones 0.5A to 2A is usually the maximum current rating for a good solderless breadboard
Here are what you need:
Your Arduino.
An external power supply. Get something like this for your external power suply.
You led strip.
Connect:
PWM pulse of Arduino -> Data IN of led strip
All GND togheters
5V output of external power supply-> VCC of led strip
Computer -> USB -> Arduino
External power supplies give you high current levels, perfect for many leds. Dont worry about your breadboard melting, it should be able to handle it.
So, I'm building an Arduino toy car. It runs with 4 motors and has 2 color sensors and 8 IR sensors. It must work on battery because i don't want it to be hooked to USB all the time and motors require much more current than USB can provide. So here's the problem...
When I have my arduino powered with USB cable or USB cable and battery, it works perfectly, but when I have it powered only on battery (7.2V), 4 LED's in the left color sensor glow dimmer, and the right one doesn't even work.
I should point out that some of the pins of color sensor that should be plugged in 5V or GND are plugged in digital output pins set on HIGH or LOW.
The arduino i'm working on is Arduino Mega 2560 and color sensors are TCS230.
I think you should measure supply current of the board and then check if your battery is able to provide such value. Also try to feed the board from external supply through wall adapter connector (or Arduino's Vin terminal). The idea is that you may need higher voltage and(or) current, then 7,2V.
Check to make sure you have the correct resisters values in place to drive the LEDs. You can sometimes get away without doing so but it is iffy and you can sink a lot of current you don't really need to. I found this link, "Driving LEDs with an Arduino".
I recently bought an ESP8266 (ESP-01, 1M) yet I have been unsuccessful in making it respond at all.
I have attempted to communicate with it using an Arduino Uno running the built-in BareMinimum script (and also the script described here) to work like an FTDI.
However, when any AT commands are sent to it via the Serial Monitor there is no response whatsoever using either approach.
The red power LED is on, yet the blue LED is always off.
My wiring:
GND - GND
RX - RX
TX - TX
VCC - 3v3
CH_PD - 3v3
I would love some clues as to how to solve this error,
Okay, seems like the same problem I spent hours.
Your Arduino TX has a high level of 5V. If you send a message to your ESP with this voltage you will (surely) destroy it. And I think thats happend to you.
So you have to buy a new ESP.
For the next try:
If you use a baudrate of 9600 you can just use two 10kOhm resistors to half your TX voltage. (I did this already and it worked without problems)
For sending a message to your Arduino 3.3V from your ESP are enought.
For higher baudrates you can use a logic level converter: https://learn.sparkfun.com/tutorials/using-the-logic-level-converter
I am using a 1 channel relay module for arduino uno r3 like this(the picture shows 2 relay module but i only use one relay for one bulb), http://www.geeetech.com/wiki/index.php/2-Channel_Relay_module.
The bulb is 220V.I connected my arduino pins, D13,Ground,and VCC to relay module's pin; Input,Ground,and 5v.I also cut my bulb's wire to connect it on my relay's pin: NC,NO,COM.One cut end of the bulb was attached to the COM and The other is to NO.The other wire of the bulb leaved uncut.The source of the bulb is Direct current.
I uploaded the Blinking codes in arduino uno r3.
After uploading the code, Relay module followed the arduino's code which is blinking.The thing was, The bulb wont follow.I also tried dis arranging some wires but nothing happens.
I read some of the articles that would possibly solve my problems.I found out that they are using SSR.Is this really needed?and what could I do to make the bulb follow the arduino's codes.
I need Help. Please..help me
If your relay is being energized then that side of the wiring is good, it's something on the other side that is wrong.
The output of a relay does not provide power, it is just a switch. You need to create a circuit that goes from power, through the relay, through your lamp, and back to power. If you connect to COM & NO then the lamp lights when the relay is energized; if you connect instead to COM and NC then the lamp lights when the relay is not energized.
The diagram on that relay site is a little misleading. For your purpose, try running the light bulb from the +5V pin on the Arduino, to the NO relay contact terminal on the relay board, and then grounding the COM relay contact terminal. This should work assuming:
1.) Your wiring TO the relay board is correct AND sufficient enough to operate the relay, specifically, you can hear it "click" every time the Pin 13 goes LOW/HIGH from the Blink sketch.
2.) The 220V rated bulb can actually operate at 5V.
If the bulb needs more than 5V, simply replace the wire going from the bulb to the +5V pin, with a higher voltage battery (make sure you attach the negative terminal of that battery to one of the Arduino Gnd pins).
The wiring diagram contains a lot more information than you need.
The relay module has a TTL interface - VCC, GND and one signal per relay to switch it on/off. These you should connect to the coresponding pins on your arduino(as you probably did).
Each of the relays have three screw terminals
When you switch the relay ON, two of those terminals will be connected through the relay NO-COM
When you switch it off, the relay will disconnect the other pair and connect COM-NC
The relay works as a switch, the lightbulb will be connected to the power as normal, but one of its wires(NOT the ground for safety reasons!) will be interrupted and the ends connected to the relay terminals.
BTW:
Both the relay and lightbulb are limited in how fast they react to switching, the relay takes time to switch(cca 3 - 20 ms) and the lightbulb has a large thermal inertia. If you are trying to blink really fast(more than lets say twice per second, you might have problem with that.
SSR are useful mainly for fast switching(normal relays have a limited speed) and should have longer lifetime, you can use it(it usualy has a 5V control input), but it seems pointless for a lightbulb.
220V light bulb will not operate on 5V
Could you explain
The source of the bulb is Direct current.
Power plug 220V is actualy AC.
What is actualy happening? Is the lightbulb ON or OFF permanently? Is it blinking in some wrong way?
I have an external power source (6v) that is connected to a motor and a servo, and on my arduino board I have a couple of LEDs which are powered by the onboard 5v. The external power is connected to a switch so I can turn on the motor and servo (to save battery). My main board just blinks the different LEDs. What I want to happen is that the moment my external power is switched on, the LEDs stop blinking and the code to move the servo and motor is executed. As a result I have a boolean called intro. When it is true, the LED code executes, when it is false the motor and servo code will execute. The only problem I am having is that how can the Arduino know if the external power is switched on so that the boolean can be set to false? Is there a way that the arduino can detect if the external power is on (for example checking the pins of the motor/servo?)?
The general idea is to connect the external power to an I/O pin so you can read its status. You'll also want a pull-down on the I/O pin so that it doesn't float and give random values when power is not connected.
Don't connect 6V directly to an Arduino I/O pin, it will be far enough above Vcc that the clamp diodes on the pin will activate. A series resistor like 10K to reduce the clamp current will probably be OK but still isn't the best design practice. I'd recommend a 3V3 zener diode clamp such as that on this page:
http://www.kevinmfodor.com/home/My-Blog/microcontrollerinputprotectiontechniques
Check the max input voltage on the IO pins, but you should be able to connect the external power to a pin and drive an interrupt.
The interrupt can then be used to decide if the power is on (rising edge) or off (falling edge).