i have already built a system that take a swipe action and checks with a central server and grant or denys access to power via a relay. All working on 10A 3V relays, multiple installations, all fine and dandy.
I am using esp8266 arduino to control this, 3.3v for the swipe sensor and for the 10A relay.
I am trying to use 5V 30A relays (spec SLA-05VDC-SL-C) to up the amperage but they will not respond.
I have check the wiring rig, all good, connection all the way through. The DC current is about 1.8V on the signal wire when enabled.
So, are the jumpers mis-set? I can find no documentation on these.
Do the LEDs provide any userful information? I get red at the top and green at the bottom no matter what goes on.
I am switching 240V AC so don't want to poke around the relay while it is live.
Attached is a screenshot of the rig, using D0 for the signal (same port as used for 10A 3V). Also attached the basic testing code used.
Does D0 provide enough current to pull down the relay? I have tested 2 different relays and neither work so not likely to be hardware. I have also used this cabling connection on existing boxes with 30A 5V, so i know it should work.
const int ledRed = D0;
#include <SPI.h>
#include <MFRC522.h>
#include <Wire.h>
#include <ESP8266WiFi.h>
void setup() // Runs once when sketch starts
{
Serial.begin(9600);
pinMode(ledRed, OUTPUT); // Setting the LED pin as an output
digitalWrite(ledRed, HIGH);
}
void loop() // Runs repeatedly
{
Serial.println();
Serial.print("Ready up");
digitalWrite(ledRed, HIGH); // Turning the LED on
delay(5000); // Waiting 1 second
Serial.print("Ready mid");
digitalWrite(ledRed, LOW); // Turning the LED off
Serial.print("Ready down");
}
When I see mistakes like this I worry that the poster does not know what they are doing
1.8V is not a current, it is a voltage
What is the operating voltage of the relay rather than the voltage that it can switch and what is the current required to operate it rather than the current that it can switch ?
If the Arduino is providing 5V but the voltage across the relay coil is 1.8V then that suggests to me that the relay is trying to take current from the Arduino pin that it cannot provide, hence the voltage drop
As the ESP8266 is a 3.3V device I find it unlikely that it is "serving up" 5V
It’s hard to see how you’re powering the relay module.
Can you draw out a schematic and detail of the supply and relay module.
What are the screw terminals on the left labelled?
Many of the ESP8266 pins have several functions and D0 is one of them.
Try using D1
Also your code is wrong. The relay is low level triggered to swap HIGH and LOW
Serial.print("Ready up");
digitalWrite(ledRed, LOW); // Turning the LED on
delay(2000); // Waiting 1 second
Serial.print("Ready mid");
digitalWrite(ledRed, HIGH);
delay(2000);
jim-p I thought the relay jumpers on were on H to configure the reaction for High current? And even though it was swapped around, it should also give some reaction to the Low signal. Right now I get nothing in either state.
