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Project Guidance / Re: Gmail with an ESP32
Last post by wvmarle - Today at 05:47 am
I used to have a phone in my room - you know, the wired version. People sometimes would call at night when I was sleeping, waking me up.

Then there was the mobile phone. I would usually just switch it off at night.

Now the smart phone, doing just that for me. I also don't take it in the bedroom, it's staying in the living room. No risk of midnight disturbances any more.

And emergencies... what is a true emergency, that I really have to be called about, that would be very bad if I knew a couple hours later as I'm sleeping? Can't think of any situation, really.

Installing site blockers and so yourself, then going through lengths to circumvent your own blocks... that's just stupid. Really can't think of a better way to describe that. Well, pathetic maybe.
boards will be stacked like shields.
Either SPI or I2C will work. My preference is for SPI because I know it will work over longer distances. Are the I2C pins on the Blue Pill also analog pins? Then you probably need to use SPI.
Sensors / Re: Wiring for 2 MPU6050s and ...
Last post by knorrLover - Today at 05:44 am
Hi. I'm so new to wiring generally and Arduino and everything.
So to make it really simplistic:

Before I was not using a breadboard, now I will be instead of connecting directly to my Arduino, so that a pin can connect to two wires, each connected to one of the two mpu6050s.

So Wiring:
MPU 1 -> Arduino/breadboard:
VCC -> 5V
SCL -> A5
SDA -> A4
AD0 -> GND
INT -> D2

MPU 2 -> Arduino/breadboard:
VCC -> 5V
SCL -> A5
SDA -> A4
AD0 -> 3.3V
INT -> D2

And can I still use the previously suggested code?
Code: [Select]

void setup() {
  //set the MPU pins to pullups, so the weak pullup in the Arduino tries to drag the pin up to 5V
  //but the internal protection diodes in the MPU won't let it go above 3.9V
  //so there will be a few micro-amps flowing into the MPU at all times

  pinMode(MPU1_AD0_Pin, INPUT_PULLUP); 
  pinMode(MPU2_AD0_Pin, INPUT_PULLUP); 


void loop() {
  digitalWrite(MPU1_AD0_Pin, LOW); //do this first, before making the pin an output
  pinMode(MPU1_AD0_Pin, OUTPUT); //now the pin is LOW

  //access the first MPU using address 0x68

  pinMode(MPU1_AD)_Pin, INPUT_PULLUP);  //deactivate MPU #1


And what I need to buy:
4 level shifters?
Its working for me with "AT+UART_DEF=9600,8,1,0,0" this command.
Thanks so much!

Worked with
Code: [Select]
AT version: 14 2016 18:54:01)
SDK version:2.0.0(5a875ba)
Mar 13 2018 09:35:47
Are you sure have the drivers for the usb-uart converter ?
Trying to now understand MHz433  tx & rx ????

I feel my problem is that I don't understand  what is contained in the "buf" and how the information

held in "buf" is converted at the Rx end.

What I am trying to achieve is to send 5 integers from TX and be able to convert the RX "buf" back to those same integers.

Searched the forum and found a reply from "cattledog" which I thought would fit the bill

but alas I cannot get it to work.

Perhaps some kind soul would help me out with what I have done wrong in the following sketches.

Code: [Select]


// transmitter.pde

#include <VirtualWire.h>

 int i;               // used as an index into the array
 int my_array[5];     // an array with 5 integer elements#include <VirtualWire.h>

void setup()
   vw_set_tx_pin (12);
   vw_setup(2000); // Bits per sec. Lower BPS to increase range

void loop()
  my_array[0] = 18;   
  my_array[1] = 1; 
  my_array[2] = 240;
  my_array[3] = 46;
  my_array[4] = 2;

  for (i = 0; i < 5; i++)
  vw_send((uint8_t *)my_array, sizeof(my_array));

  digitalWrite(13, true); // Flash a light to show transmitting


// receiver.pde

#include <VirtualWire.h>

int solenoid    = 0;
int onOff       = 0;
int time_length = 0;
int pressure    = 0;
char my_array    [5];

void setup()

    vw_setup(2000); // Bits per sec

    vw_rx_start();       // Start the receiver PLL running

void loop()

    uint8_t buf[VW_MAX_MESSAGE_LEN];
    uint8_t buflen = VW_MAX_MESSAGE_LEN;

   if (vw_get_message(buf, &buflen))

   // Turn on a light to show received good message
   digitalWrite(13, true);


   int i;
   for (i = 0; i < buflen; i++)
   solenoid       =  my_array[0];
   onOff          =  my_array[1];
   time_length    =  my_array[2];
   pressure       =  my_array[3];


   Serial.println (solenoid);
   Serial.println (onOff);
   Serial.println (time_length);
   Serial.println (pressure);

   delay (1000);
   digitalWrite(13, false);

Thanks in advance
If you consider your problem resolved, please edit your post to include SOLVED in the subject text. This will save others the time from looking at a closed issue. Thanks.
Which driver do you have?

I have used a DRV8825 with the Arduino controlling the current limit input. So I could control the current limit at any time.
As a point of answering "why ?', <> instructs the linker to check the library paths as defined by your installation for the particular file. Double quotes specifies a directory which, with nothing else but the header file name, defaults to the directory that also contains the source code.
Displays / Re: Good Dispay ePaper for Ard...
Last post by noelportugal - Today at 05:39 am
Yeah, that did it! thanks again. Soon I'll share here what have I been working on  8)
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