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Displays / Re: 3.5" TFT display problem
Last post by ZinggJM - Today at 03:44 pm
I avoid shopping from ebay, especially electronics. My experience with AliExpress is positive with very few exceptions.
But this time I should have consulted feedback before ordering, as I usually do.
"item is not as described. damaged screen come packed well but..."
"this seller заказывал two different display, other size and another this... come in about 55 days via the parcel pack".

The schematics does not correspond to the picture from @HPJ, e.g. 6 RP versus 9 RP.

So I give up guessing and wait curiously for what and if and when I will get. One more lesson learnt.


Project Guidance / Using the USB hist shield
Last post by barryjo - Today at 03:44 pm
I posted this issue on another section but I thought I might get others ideas from this section.

I have a USB host shield on my Arduino uno. I am using the USB HNOST-master library version 2. I find that I can use one of the example programs with a keyboard and it works. I even have a wireless KB/mouse and when I try it the mouse works but not the KB.

Does anybody know what I can do to make the example SW work with all of the devices?

In fact, I really want to interface to a game controller joystick. The example does not work with ,my Logitech F310 for some reason.

Since the Uno/shield does work with a KB and a mouse, I assume that the hardware is OK. There must be some sort of setting in the software to allow the shnield/library to connect to other devices.

I am not a USB expert so I guess I am in for some digging.
I got another question now, do you think I can plug 2 ADNS 9800 to one arduino UNo?
    Works with Arduino SPI library
So, as long as you use a different Slave Select (sometimes called chip select) pin for each device, you can connect as many as you have pins, and read them all independently.
Deutsch / Re: [Suche Hilfe]Buttons für T...
Last post by MaHa76 - Today at 03:44 pm
Mit der UTFT hab ich auch mal gekämpft... erfolglos, obwohl ich sagen muss, dass die UTFT eigentlich sehr gut ist... Allerdings bin ich inzwischen bei sumotoy´s lib zum RA8875 gelandet- darum kann ich dir mit der UTFT in keinster Weise helfen.

Aber ich denke der händische Weg, den wir schon weiter oben gezeigt haben, ist doch nicht so kompliziert- oder?

Sensors / Which sensor to use for detect...
Last post by Akshay00719 - Today at 03:42 pm
Currently I m working on project where I hav to detect the humans presences in room I tried out PIR senior but device get off when there is no motion done by humans even though there are inside the room.(e.g if someone is watching movie and is still) .so to overcome such problem can anyone suggest me a good senior which just hav to detect the humans presences .

I don't want to measure distance or temperature of human which are inside room.

It would be better if someone suggests better IR sensor which just hav to detect IR present inside the room.

Please help me out :(  :(  :(
How does this resistor bring the system back in the initial condition?
It doesn't, it is a pull down resistor for the input to keep the pin's voltage at zero when the button is not pressed. It stops the pin floating and picking up random crap.
Bar Sport / Re: [OT ITA] Lo spamm bar
Last post by Etemenanki - Today at 03:41 pm
... senza manco dover usare millis() ma usando solo delay()  :smiley-yell: :smiley-yell: :smiley-yell:

... visto che c'era, il sistema per non usare millis per forza ? ... :D :D :D
Hi everyone.
i have difficulty programming an attiny85 that collects data from a dht22 sensor and transmits it using a HC12 module. I need to send temperature and humidity data from the dht22 to an arduino mega using HC12 modules. Kindly advise.
The code for TX is shown below:

Code: [Select]
#include <SoftwareSerial.h>
#include <dht.h>   
dht DHT;
#define DHT22_PIN 4

const byte HC12Rxdpin=1;
const byte HC12Txdpin=0;

String HC12ReadBuffer;
boolean HC12End=false;
SoftwareSerial HC12(HC12Txdpin,HC12Rxdpin);

//byte currentNodeAddr[6]="1Node";
float h=0;
float t=0;
int transmit_t=0;
int transmit_h=0;
int transmit_data=0;
int led=3;

void setup() {
  pinMode(1, OUTPUT);
pinMode(0, INPUT);
pinMode(4, INPUT);
pinMode(3, OUTPUT);

void loop() {
  uint32_t start= micros();
 int chk= DHT.read22(DHT22_PIN);
  uint32_t stop= micros();


The RX code:

Code: [Select]
#include <SoftwareSerial.h>;

const byte HC12RxdPin = 11;                  // Recieve Pin on HC12
const byte HC12TxdPin = 10;                  // Transmit Pin on HC12

SoftwareSerial HC12(HC12TxdPin,HC12RxdPin); // Create Software Serial Port

void setup() {
  Serial.begin(9600);                       // Open serial port to computer
  HC12.begin(9600);                         // Open serial port to HC12

void loop() {
  if(HC12.available()){                     // If Arduino's HC12 rx buffer has data
    Serial.write(;              // Send the data to the computer
  if(Serial.available()){                   // If Arduino's computer rx buffer has data
    HC12.write(;              // Send that data to serial
Deutsch / Re: Bürstenmotor mit ESC über ...
Last post by dony - Today at 03:40 pm

In Deinem Code steht
Code: [Select]
int state; // stores incoming character from other device
Du verwendest allerdings Buchstaben (zB.: V).
Du musst das in
Code: [Select]
char state; // stores incoming character from other deviceändern.

int = Zahlen, char = BuchstabenUndZahlen
Ich bin allerdings der Meinung das 'int' zu lassen und die Buchstaben durch Zahlen zu ersetzen.

Was das Rückwärtsfahren angeht, fällt mir leider nichts mehr ein.

lg dony
I do not understand why you would say that a string has no place on an Arduino. There are a bunch of string functions that are useful when dealing with parsing keyboard inputs. For example adding two strings is a lot easier than adding two arrays. It seems to me that the string functions eliminate a lot of code to write if only using arrays.

I have a function that claimed to accept both a string or array as a data input. Unfortunately, the function worked with an array and some but not all strings. I have not dug into the function to see where the problem is. I just converted the string to an array and continued.
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