I brought an esp8266-12, it works at 115200 baud rate. I sometime connect it to arduino uno to work for some projects. It would be easy if I connect esp8266 with arduino at 9600 baud rate. The AT version is 0.25. I googled and saw the AT command set documentation it had a command to set baud rate. It was like
AT+ UART_DEF=<baudrate>,<databits>,<stopbits>,<parity>,<flow control>
But the problem is I don't know what these parameters are and how to set the parameters so that is works at 9600 baud rate with arduino.
After a long time of searching, I found the parameters to work with Arduino at 9600 baud rate.
AT+UART_DEF=9600,8,1,0,0
To change the baud rate of esp8266, use this command.
AT+CIOBAUD=9600
Easy and simple. Command can be sent through serial communication from Arduino UNO.
Related
I am trying to integrate an RFID1356MIFARE, which uses NXP PN532, with an ESP32-EVB using their UART capabilities.
The NXP docs states that the PN532 is able to communicate on High Speed UART.
I am trying to use 38400 because that's the baud rate fixed by the reader that I'm using.
I've found a modified Adafruit PN532 library that added HSU support. This library states that HSU uses 115200 baud rate.
Now, I've modified PN532_HSU.cpp, where we can find:
void PN532_HSU::begin()
{
_serial->begin(115200);
}
into
void PN532_HSU::begin()
{
_serial->begin(38400, SERIAL_8N1, 36, 4);
}
Unfortunately, I haven't been able to establish communication between the reader and the ESP using this method.
I am able to get a readable output using normal Serial.read(), so UART communication works, but that's not how you read MIFARE cards.
I don't know what the problem is.
What do you think ?
[EDIT]
I went through the documentation and here is what i suggest: If you have a USB to serial device use it to directly connect reader module to computer else connect it directly using mini USB port in module. the follow following steps:
Put device in UART/ USB CDC mode depending on how you connected device to computer. Exact method to do this is provided in operation section of documentation
Use picoterm / screen or other serial terminal (if you are using Linux) or just use Arduino serial monitor with correct baud rate to connect device.(115200 for USB and 38400 for UART)
Type in commands listed in COMMAND SET FOR CDC AND UART MODE section in documentation to check if module is working or not.
Place some cards over reader to check what response does module sends when card is detected.
Use this information to develop your own library for reader.
It will not work with regular PN532 libraries. Instead you'll need to use regular Serial read and write to communicate.
[Original]
PN532 datasheet says host interface is selected by pulling up/down I0, I1 pins of device. For HSU both pins must be pulled down. This is implemented in hardware so you need to verify if the mode you want to use is set.
Looking into the link you posted for module, it says that it uses another micro-controller on board to extend communication capabilities, so maybe you need to use driver for that specific controller firmware? The link seems to have document explaining how to setup different communication system in Document section, please have a look there and check if it works.
Link: https://www.olimex.com/wiki/MOD-RFID1356MIFARE
I am connecting a 74ls151 to rpi 3 and what to use it as a demultiplexer for switching mpu6050 on/off.
Can the 74ls151 be used as demultiplexer?
No it cannot be used as it does not have a bi-directional mechanism. It can be used to multiple between devices that send data to the raspberry pi or arduino, but it cannot receive any data or voltage from the raspberry pi or arduino. So, it is uni-directional.
I have an arduino Uno which collect data from sensor, i want to send this data to the cloud using wifi esp8266 who support SSL using the library WifiClientSecure, is there an alternative to send data from arduino to the esp card and esp8266 read this data and send it after that to the cloud, i'm able to work with mqtt but i want to know if there is a way to have a directly connection between the arduino uno and esp8266 without having a third part, any help will be gratefull.
According to my research, the ESP8266 AT Command API does not support SSL. This means you will need to use the Arduino (as an FTDI converter) to program the ESP8266 with custom firmware. This will enable you to use WiFiClientSecure and pubsubclient.
To use the Arduino as an FTDI:
load a sketch that does not use Serial, such as the "Blink" example
connect the Arduino's TX pin to the ESP8266 RX pin
connect the Arduino's RX pin to the ESP8266 TX pin
Now you need to setup Arduino IDE so it can program an ESP8266
In Arduino IDE -> File -> Preferences, paste this into the Additional Boards Manager URLs: http://arduino.esp8266.com/stable/package_esp8266com_index.json (just copy the link as it is instead of clicking)
go to Tools -> Boards -> Boards Manager. Find "esp8266" in the list of boards and click "Install"
Set your board to "Generic ESP8266 Module" in Tools -> Boards
Arduino IDE is ready! But before you caan program an ESP8266 with it you need to connect a reset button and a program button to the ESP8266.
connect a push-button between GND and the ESP8266 GPIO_0 pin
connect a push-button between GND and the ESP8266 RESET pin
add a 10K-ohm pull-up resistor between 3.3V and ESP8266 pin (defaults the reset pin to HIGH)
When you are ready to upload a sketch to the ESP8266, use those buttons like this:
press both buttons
release RESET button
release GPIO_0 button
This puts the ESP8266 in program mode! You should now be able to click the "Upload" button in Arduino IDE. I would suggest using one of the provided ESP826a6 example sketches (like this one) to test everything out.
Here's an overview of the project:
. Arduino Uno sketch: read sensor data, send via Serial to ESP8266
. ESP8266 sketch: connect to WiFi network, receive sensor data from Serial, send via WiFiClientSecure to the cloud.
I will leave the actual code of these two programs up to you, but if you get stuck just leave a comment. Hope this helps!
I recently try to use Lidar Lite v3 with my Rpi 3, and it works with I2C communication. My wiring method is due to offical documentation. Wiring picture However, what I have learned before is that the gpio pin of RPI can only afford 3.3v working voltage. My Question is that shouldn't I add the resistor in my circuit to prevent from breaking out the pins of my RPI ?
In 802.11 WLAN, there is data rate change of the connection as Dynamic rate scaling or Automatic Rate Selection is working. Is there any event triggered from the card so as to notify the OS (Linux Kernel event) about the same?
I know something about "iw events". Unfortunately it does give events like association, authentication etc but not of the data rate changes.
Please let me know if anyone aware of such functionality on any wireless card.
Thanks, Kedar
TX or RX rate?
It also depends on what kind of driver is used. If the rate control algorithm is implemented in the firmware then likely it's not possible. If the driver uses mac80211 then you can create a monitor interface and use e.g. tcpdump:
% sudo iw phy0 interface add mon0 type monitor
% sudo ifconfig mon0 up
% sudo tcpdump -ni mon0
Then you'll also get quite some information about the PHY for each packet.