Recent Posts

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1
General Electronics / Re: Stable time measurement
Last post by MarkT - Today at 11:43 am
The Teensy 3.6 has two oscillators, the high speed CPU clock which should be accurate to about 1 part in 1000 or so and the 32 kHz embedded real time clock oscillator which I would expect is of similar accuracy as the DS3231, that is, a few parts per million.  Which one are you using for this comparison?
Surely its a standard watch xtal used for 32.768kHz?  They are typically 30, 50 or even 100ppm.
The DS3231 uses a TCXO with basic accuracy of a few ppm.  For better clock accuracy you require a TCXO
or OCXO, not a bog-standard xtal.
2
Software / Re: OLED I2C 128x64 - Aiuto
Last post by go3mon - Today at 11:41 am
si! ho cliccato su Select e copiato nell'IDE. :o
3
Project Guidance / Graph possible on tft or too m...
Last post by pwatsoon - Today at 11:41 am
Hi All,

Basically building a temperature and humidity controller. Reads values from AM2315 sensor and displays on screen under a banner. Also some buttons to select required values. At the moment I don't have the output relays to hand so that part of the code is missing just now but reading and displaying values and selecting values all works great.

My thought is would it be possible to make the logo into a button which changes the screen to a line graph showing both readings across the screen? pushing the logo again would return to the original screen. This is not totally necessary I thought it might just be a nice touch. Any suggestions or advice would be appreciated.

My code so far for changing the screen is here :

Code: [Select]
void graphSelector(){
  TSPoint p = ts.getPoint();
  
  if (p.y>840 && p.y<950 && p.x>130 && p.x<900){
  Serial.println ("Logo pressed");
  tft.fillScreen(ILI9341_WHITE);
  }
  int tempSensor = (am2315.getTemperature_C());
  int humiSensor = (am2315.getHumidity());

}


4
Programming Questions / Re: timelib.h problems
Last post by PaulS - Today at 11:40 am
Any idea why im getting thease results? Thanks
Something is wrong in the code you didn't post. Before posting more code, though,










get rid of the










excess white space, and use
                    Tools + Auto Format
        to fix your piss-poor indenting.
5
Software / Re: OLED I2C 128x64 - Aiuto
Last post by gpb01 - Today at 11:39 am
Ma hai fatto quanto ho scritto sopra la post #3 ? ? ? :o

Perché l'ho provato e non da alcun problema !

Guglielmo
6
Project Guidance / Re: 4 channel relay board
Last post by marpik - Today at 11:39 am
... This is the current required to energize the relay. The opto-isolator's transistor will see this current. The Arduino control current will be 15-20mA through each control input (IN1-IN4).

Not true :) Although I fully agree with the fact that the board requires separate power supply (Arduino power supply would not be able to energize all relays), the optoisolator driving current will be much smaller than 15-20 mA.

Each relay control input, connected to Arduino control output, is active low, that means it must be connected to ground to activate the relay. However, Arduino output voltage at low level is not 0V, Atmel ATmega328P datasheet shows Vol voltage (voltage on output pin set to "0") at sink current below 10mA being approx 0.6 V.

The control current runs from Vcc voltage through 1kohm limiting resistor, through optoisolator LED and through red indicator LED to control input (which is ~ 0.6 V in active low state). Voltage drop on 817 optoisolator LED is approx. 1.2V, voltage drop on red SMD indicator LED (in series with optoisolator) is around 1.8 V. When connected to +5.0 V power supply, voltage on 1kohm limiting resitor will be around  1.4 V (5.0 - 1.2 - 1.8 - 0.6), resulting in 1.5 mA sink current from each control input.
7
Deutsch / Re: Fragen zum Grove Light Sen...
Last post by HotSystems - Today at 11:37 am
~52.000lx der nackte Sensor, 65.000lx mit geeigneter mattierter Kuppel.
Dann sieh dir mal an, was der TO möchte.
Das geht mit jedem beliebigen LDR wohl auch.

Nur ohne Erfahrung und Grundlagen muss man da schon ein wenig üben.

Und er braucht kein "Präzisionsinstrument".
8
Code: [Select]
  if (analogRead( detect) == 0)     
What, EXACTLY, is connected to this pin? Why doesn't the detect variable have pin in the name, to make it clear that it holds a pin number?

Why are you expecting an analog value of exactly 0?

Code: [Select]
.
 .
 .
 etc

There is not a snowball's chance in hell that the code you posted will compile. Why are you wasting our time?
9
See the Image Guide





The above images make it look like you are well on your way to solving the problem.

Code: (Here is your forwards code...) [Select]
    if(bt == 'F')        //move forwards
    {
      analogWrite(outPin1,speed);
      digitalWrite(outPin2,LOW);
      analogWrite(outPin3,speed);
      digitalWrite(outPin4,LOW);
     

It is showing error as 'use of undeclared identifier speed'
10
Deutsch / Re: Spannungs-/Stromversorgung...
Last post by MarcusP - Today at 11:36 am
Also muss ich mir keine Sorgen machen bezüglich meines Netzteils, wenn ich mehrere gleichzeitig ansteuere?
Da ich 4 von diesen Netzteilen mit je 4 Kanälen am Prüfstand habe. Muss ich keinen Kondensator vorher anschließen? Oder soll ich auf Nummer Sicher gehen und dies trotzdem tun?
Du hast ja schon Kondensatoren im Netzteil, und wenn das Netzteil innerhalb seiner Spezifikationen betriebenen wird sollte es kein Problem geben.

Aber beides mal ausprobieren und Ossi dran halten schadet nicht.

hth
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