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Hardware / Re: Gestione movimentazione/sc...
Last post by Claudio_FF - Today at 04:22 pm
Con gli optoisolatori si possono anche realizzare i comandi per gli scambi 12Vca:
Robotics / Re: PID to control robot move ...
Last post by syedmoosa - Today at 04:22 pm
i am using 2 encoders to control the motor and move the motor in straight path but i cant able to run the motors on straight path due to the difference in speed in both the motors.
my encoder has total 20 slots.

please send a code to run both motors in straight path using encoders.

thanks in advance
Bar Sport / Re: [OT ITA] Lo spamm bar
Last post by gpb01 - Today at 04:22 pm
Tragedia a Genova, ponte crollato e per ora giĆ  20 vittime.    :o :'(
... :o :o :o ... incredibile !!!

Hi please suggest me what to do now..
added all of Leo's recommendations (from this thread and the other)
Leo, can you make sure I wired the CT circuits up right?
switched to MCP23008
changed the layout to enhance readability
added addr pin on ADC
will not have Alert Pin (dont need it, and dont have room for it on the esp12)
Next, I tried switching to Serial (to make it Arduino Uno ++ compatible). Now I get lots of CRC errors (maybe 50% of all the packets received have CRC error).
As you have not posted your program it is a bit difficult to see what the problem might be.

Also post diagrams showing how you have everything connected in the working and non-working situation.

My guess is that you need to use SoftwareSerial on the Uno - but it won't work at 115200 baud. 9600 works well and 38400 should work. And if that is not an option then maybe an Uno is unsuitable.

I'm trying to consider why one wouldn't use an opamp buffer in this design?
It makes sense to me - accurate readings, no load on source circuit.
I'm revisiting this circuit.  I had shelved it for quite some time.

The reason being is that I have limited experience with circuit and this would be over my head.  If you wouldn't mind offering some links or guides I would be extremely grateful.
Hello, Arduino Community!

I wasn't able to provide the circuit schematics on my last post (last, last week) and I think that updating it would make it more convoluted. I really wanted to put things to an end for this particular matter. So again, I'm trying to design a wireless fire alarm prototype using ZigBee and Arduino. My circuit is as follows in the attached image.

My problem is that despite using some calibration and software filtering techniques, my ADC readings for monitoring the battery voltage are still inaccurate. I believe it comes from the hardware and the software as well from all that I've read online.

I've been using bypass caps on every other component and on the power lines for the Arduino but the noise still persists. I kind of gave up and removed every cap I have on the circuit. Readings were quite good (+-0.02-0.06 V diff. vs. multimeter) the first time but after a few days of testing and by charging the battery simultaneously while measuring, readings have become even worse. I have little to no electronics background and have no oscilloscope. Kind of sucks. Sorry

I've read about filters (RC) online and tried them by doing slight calculations and random choice of caps from the smallest ones and seeing which one had the best result. However, I really wanted to know how to use them on any circuit. I've also read the software also affects the RC values as well. Too bad I don't have an oscilloscope with me. :(

So my questions are:
1. How do I choose the component values of my RC circuit?
2. What frequencies do I have to take in mind? The sampling frequency of my ADC or the noise which I want to cut off? If both, how should I implement the solution?
3. How does software affect ADC measurements? (I've read ones like digitalWrite particularly at high frequencies do some serious noise)
4. What are my possible approaches to this?

Thank you very much. I'm sorry but it obviously seems I am asking for much but I really have a lot of questions in mind.

Photos are in my drive on high resolution. :)
Arduino Due / Arduino -Due SPI read and unex...
Last post by nagu3112 - Today at 04:18 pm

I am using Arduino-Due and interfaced a sensor using below SPI pins.
I read 1 byte of data from 0x80 register and did not get the expected value from the register when I read. (I get random values every time)
Could someone help to point out if I use the APIs properly?

MISO - Physical pin #108
MOSI - Physical pin #109
MSCK - Physical pin #110
CS1 - Physical pin #137

1MHz Baud rate
I did not set the bit order

Arduino and sensor interfacing
#include <stdint.h>
#include <SPI.h>
#include <Wire.h>

const int slaveAPin = 4;

void setup()   



void loop()

void sensor_spi_settings(void)
  /* SPI Init */
  pinMode (slaveAPin, OUTPUT);
  digitalWrite(slaveAPin, HIGH);
  // initialize the bus for the device on pin 4
  SPI.setClockDivider(slaveAPin, 84);


void sensor_chip_id(void)
    uint8_t reg_adr;
    uint8_t reg_data;
    reg_adr = 0x80;
    reg_data = SPI.transfer(slaveAPin,0x00);
    Serial.print("Chip-ID : ");
    Serial.print(reg_data, HEX);


You should wire GND - BUTTON - D6. With input_pullup it reads LOW when pressed.
I don't know prng I use the Truerandom library
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