I'm using an OLED 128*64 display screen with NodeMCU ESP8266.
when I tried to detect the screen address, the serial monitor shows:
enter image description here
It would be kind if someone can tell me what is the problem ? and how t solve it ?
Hi Mari please try this I2c tester: it will give you the number of devices and their addresses
#include <Wire.h>
byte errorResult; // error code returned by I2C
byte i2c_addr; // I2C address being pinged
byte lowerAddress = 0x08; // I2C lowest valid address in range
byte upperAddress = 0x77; // I2C highest valid address in range
byte numDevices; // how many devices were located on I2C bus
void setup() {
Wire.begin(); // I2C init
Serial.begin(115200); // search results show up in serial monitor
}
void loop() {
if (lowerAddress < 0x10) // pad single digit addresses with a leading "0"
Serial.print("0");
Serial.print(lowerAddress, HEX);
Serial.print(" to 0x");
Serial.print(upperAddress, HEX);
Serial.println(".");
numDevices = 0;
for (i2c_addr = lowerAddress; i2c_addr <= upperAddress; i2c_addr++ )
// loop through all valid I2C addresses
{
Wire.beginTransmission(i2c_addr); // initiate communication at current address
errorResult = Wire.endTransmission(); // if a device is present, it will send an ack and "0" will be returned from function
if (errorResult == 0) // "0" means a device at current address has acknowledged the serial communication
{
Serial.print("I2C device found at address 0x");
if (i2c_addr < 0x10) // pad single digit addresses with a leading "0"
Serial.print("0");
Serial.println(i2c_addr, HEX); // display the address on the serial monitor when a device is found
numDevices++;
}
}
Serial.print("Scan complete. Devices found: ");
Serial.println(numDevices);
Serial.println();
delay(10000); // wait 10 seconds and scan again to detect on-the-fly bus changes
}
the wiring should be for I2C connection:
D2 -> SDA, D1 -> SCL, GND -> GND, (*) -> Vcc
(*) check what oled model you have, some work at +5V other at +3.3V that might be the issue
Moreover usually the pullup resistor is not needed (check your model specs)
Check also the specification of your oled, sometimes some jumper setup is needed
I found the problem: I didn't insert the nodemcu properly inside the board.
Related
Please i wish somebody could help me with this. I've been struggling into it since a couple of weeks, i am so new to that.
I want to send data from ESP32 SIM800L to a mqtt broker.
The mqtt server is running on my local machine and the ESP32 SIM800 can perfectly connect to APN.
I saw many tutorials doing it with WIFI connection but not GPRS(what i am using).
I finally find this: tinyGSM and this :arduino mqtt mongodb
And i adapted it as follows, but still getting connection failed:
// Your GPRS credentials (leave empty, if not needed)
const char apn[] = "internet.tn"; // APN (example: internet.vodafone.pt) use https://wiki.apnchanger.org
const char gprsUser[] = ""; // GPRS User
const char gprsPass[] = ""; // GPRS Password
// SIM card PIN (leave empty, if not defined)
const char simPIN[] = "";
uint32_t lastReconnectAttempt = 0;
// TTGO T-Call pins
#define MODEM_RST 5
#define MODEM_PWKEY 4
#define MODEM_POWER_ON 23
#define MODEM_TX 27
#define MODEM_RX 26
#define I2C_SDA 21
#define I2C_SCL 22
// Set serial for debug console (to Serial Monitor, default speed 115200)
#define SerialMon Serial
// Set serial for AT commands (to SIM800 module)
#define SerialAT Serial1
// Configure TinyGSM library
#define TINY_GSM_MODEM_SIM800 // Modem is SIM800
#define TINY_GSM_RX_BUFFER 1024 // Set RX buffer to 1Kb
#include <Wire.h>
#include <TinyGsmClient.h>
#include <PubSubClient.h>
#ifdef DUMP_AT_COMMANDS
#include <StreamDebugger.h>
StreamDebugger debugger(SerialAT, SerialMon);
TinyGsm modem(debugger);
#else
TinyGsm modem(SerialAT);
#endif
// I2C for SIM800 (to keep it running when powered from battery)
TwoWire I2CPower = TwoWire(0);
const char* broker = "localhost";
const char* topicInit = "GsmClientTest/init";
// Function prototypes
void subscribeReceive(char* topic, byte* payload, unsigned int length);
// TinyGSM Client for Internet connection
// gsm and MQTT related objects
TinyGsmClient client(modem);
PubSubClient mqtt(client);
long mqtttimer = 0; // Timer for counting 5 seconds and retrying mqtt connection
byte mqtttarea = 1;
#define uS_TO_S_FACTOR 1000000 /* Conversion factor for micro seconds to seconds */
#define TIME_TO_SLEEP 3600 /* Time ESP32 will go to sleep (in seconds) 3600 seconds = 1 hour */
void mqttCallback(char* topic, byte* payload, unsigned int len) {
SerialMon.print("Message arrived [");
SerialMon.print(topic);
SerialMon.print("]: ");
SerialMon.write(payload, len);
SerialMon.println();}
boolean mqttConnect() {
SerialMon.print("Connecting to ");
SerialMon.print(broker);
// Connect to MQTT Broker
boolean status = mqtt.connect("GsmClientTest");
// Or, if you want to authenticate MQTT:
//boolean status = mqtt.connect("GsmClientName", "mqtt_user", "mqtt_pass");
if (status == false) {
SerialMon.println(" fail");
return false;
}
SerialMon.println(" success");
mqtt.publish(topicInit, "GsmClientTest started");
// mqtt.subscribe(topicLed);
return mqtt.connected();}
void setup() {
SerialMon.begin(9600);
// Start I2C communication
I2CPower.begin(I2C_SDA, I2C_SCL, 400000);
// Set modem reset, enable, power pins
pinMode(MODEM_PWKEY, OUTPUT);
pinMode(MODEM_RST, OUTPUT);
pinMode(MODEM_POWER_ON, OUTPUT);
digitalWrite(MODEM_PWKEY, LOW);
digitalWrite(MODEM_RST, HIGH);
digitalWrite(MODEM_POWER_ON, HIGH);
// Set GSM module baud rate and UART pins
SerialAT.begin(9600, SERIAL_8N1, MODEM_RX, MODEM_TX);
delay(3000);
// Restart SIM800 module, it takes quite some time
// To skip it, call init() instead of restart()
SerialMon.println("Initializing modem...");
modem.restart();
// use modem.init() if you don't need the complete restart
// Unlock your SIM card with a PIN if needed
if (strlen(simPIN) && modem.getSimStatus() != 3 ) {
modem.simUnlock(simPIN);
}
SerialMon.print("Connecting to APN: ");
SerialMon.print(apn);
if (!modem.gprsConnect(apn, gprsUser, gprsPass)) {
SerialMon.println(" fail");
}
else {
SerialMon.println(" OK");
}
// MQTT Broker setup
mqtt.setServer(broker, 1883);
mqtt.setCallback(mqttCallback);
esp_sleep_enable_timer_wakeup(TIME_TO_SLEEP * uS_TO_S_FACTOR);
}
void loop() {
// This is needed at the top of the loop!
if (!mqtt.connected()) {
SerialMon.println("=== MQTT NOT CONNECTED ===");
// Reconnect every 10 seconds
uint32_t t = millis();
if (t - lastReconnectAttempt > 10000L) {
lastReconnectAttempt = t;
if (mqttConnect()) {
lastReconnectAttempt = 0;
}
}
delay(100);
return;
}
mqtt.publish(topicInit, "Hello");
mqtt.loop();
}
You set the broker's name to localhost:
const char* broker = "localhost";
localhost and the IP address 127.0.0.1 mean "the host that this code is running on". When you're typing commands on the computer running the broker, localhost will mean that computer. There's no way it will work on the ESP32.
You need to name or IP address of the computer running the broker. How you find that will depend on the operating system you're running.
If that computer is on your local network it's probably using a private IP address like 10.0.1.x or 192.168.1.x. If that's the case you'll need to either use port forwarding in your router to forward packets to it (and then you'll use your router's IP address and not your broker's).
If you're using your router's IP address, that can change without warning, so you'll need to use something like Dynamic DNS to keep up to date with its current IP address.
You'll likely be better off running the broker outside of your network on a cloud-based virtual server or by using one of the several commercial MQTT services out there. Most of them have a free tier which will allow a reasonable amount of traffic per month.
Regardless, localhost will never work here. You need the real, public IP address or name of your broker.
I am having this error whenever I try to debug my program using Code Composer Studio V 9.1.0 :
CORTEX_M4_0: Trouble Reading Memory Block at 0x400043fc on Page 0 of Length 0x4: Debug Port error occurred
I am using a Texas Instruments TM4C123GXL launchpad, and it connects to my laptop via a USB cable. I can successfully build my program, but the errors show up whenever I try to debug my program. My program is supposed to use SysTick interrupts to continuously vary the voltage on an Elegoo membrane switch module to allow the program to see which button I've pressed. I'm not 100% sure I've correctly initialized the GPIO input and output ports, but the errors occur before the program even starts and reaches my main loop.
Here is a screenshot of some code and my errors:
Here is some code:
void SysTickInit()
{
NVIC_ST_CTRL_R = 0;
NVIC_ST_RELOAD_R = 0x0C3500; // delays for 10ms (800,000 in hex) '0x0C3500' is
// original correct
NVIC_ST_CURRENT_R = 0;
NVIC_ST_CTRL_R = 0x07; // activates the systick clock, interrupts and enables it again.
}
void Delay1ms(uint32_t n)
{
uint32_t volatile time;
while (n)
{
time = 72724 * 2 / 91; // 1msec, tuned at 80 MHz
while (time)
{
time--;
}
n--;
}
}
void SysTick_Handler(void) // this function is suppose to change which port
// outputs voltage and runs every time systick goes
// to zero
{
if (Counter % 4 == 0)
{
Counter++;
GPIO_PORTA_DATA_R &= 0x00; // clears all of port A ( 2-5)
GPIO_PORTA_DATA_R |= 0x04; // activates the voltage for PORT A pin 2
Delay1ms(990);
}
else if (Counter % 4 == 1)
{
Counter++;
GPIO_PORTA_DATA_R &= 0x00; // clears all of port A (2-5)
GPIO_PORTA_DATA_R |= 0x08; // activates voltage for PORT A pin 3
Delay1ms(990);
}
else if (Counter % 4 == 2)
{
Counter++;
GPIO_PORTA_DATA_R &= 0x00; // clears all of port A (2-5)
GPIO_PORTA_DATA_R |= 0x10; // activates voltage for PORT A pin 4
Delay1ms(990);
}
else if (Counter % 4 == 3)
{
Counter++;
GPIO_PORTA_DATA_R &= 0x00; // clears all of port A (2-5)
GPIO_PORTA_DATA_R |= 0x20; // activates voltage for PORT A pin 5
Delay1ms(990);
}
}
void KeyPadInit()
{
SYSCTL_RCGCGPIO_R |= 0x03; // turns on the clock for Port A and Port B
while ((SYSCTL_RCGCGPIO_R) != 0x03) { }; // waits for clock to stabilize
GPIO_PORTA_DIR_R |= 0x3C; // Port A pins 2-5 are outputs (i think)
GPIO_PORTA_DEN_R |= 0x3C; // digitally enables Port A pins 2-5
GPIO_PORTA_DIR_R &= ~0xC0; // makes Port A pin 6 and 7 inputs
GPIO_PORTA_DEN_R |= 0XC0; // makes Port A pin 6 and 7 digitally enabled
GPIO_PORTB_DIR_R &= ~0X03; // makes Port B pin 0 and 1 inputs
GPIO_PORTB_DEN_R |= 0x03; // makes PortB pin 0 and 1 digitally enabled
}
I found out why my error was occurring. I went to my professor and he had a custom-built device to check if my pins on my launchpad were working. It turns out some of the pins I was using on Port A and B drew too much current, and according to the custom-built device, became busted. In other words, this error came about because the IDE detected that some of my pins weren't operational anymore.
In my case I had to disable the AHB (advanced high-performance bus) in the GPIOHBCTL register to read the GPIO_PORTx register. If you want to read the register when the AHB is activated you must read the GPIO_PORTx_AHB register.
Access to GPIO_PORTA_AHB register when AHB is activated - it works
Access to GPIO_PORTA register when AHB is activated - it fails
The Solution is to enable The clock getting into the peripheral using the RCC Section
I am implementing a sniffer with the help of winpcap. Now I am getting packets and updating UI with background worker. Now I am trying to apply a filter on the packets, so I decided to use pcap_compile() and pcap_setfilter() API's . But pcap_Compile() needs a netmask so I was using the following code
for(pIf=pIfList,i=0; i<num-1; pIf=pIf->next,i++);
// Open the device.
if((pPcap= pcap_open(
pIf->name, // name of the device
65536, // portion of the packet to capture
PCAP_OPENFLAG_PROMISCUOUS, // promiscuous mode
1000, // read timeout
NULL, // authentication on the remote machine
err // error buffer
)) == NULL)
{
printf("\nUnable to open the adapter. %s is not supported by WinPcap\n",pIf->name);
//goto Exit; //one function is nedded*/
}
gPcap = pPcap;
if (pIf->addresses != NULL)
/* Retrieve the mask of the first address of the interface */
net=((struct sockaddr_in *)(pIf->addresses->netmask))->sin_addr.S_un.S_addr;
else
/* If the interface is without an address we suppose to be in a C class network */
net=0xffffffff;
//compile the filter
if (pcap_compile(gPcap, &fcode, "type ctl subtype rts", 0, net) < 0)
{
fprintf(stderr,"\nUnable to compile the packet filter. Check the syntax.\n");
/* Free the device list */
pcap_freealldevs(alldevs);
return -1;
}
//set the filter
if (pcap_setfilter(gPcap, &fcode) < 0)
{
fprintf(stderr,"\nError setting the filter.\n");
/* Free the device list */
pcap_freealldevs(alldevs);
return -1;
}
I am getting netmask value as zero. and I used different filter expressions like "type mgt", "type ctl",type data", " ip" etc.. but the filter action is not working, it is giving all the packets. I am not understanding why the filter is not working. could you suggest me?
I am using a following API to get the packets:
restart:
status = pcap_next_ex( pPcap, &header, &pkt_data);
{
if(status == 0)// Timeout elapsed
goto restart;
}
The above code I am running in a infinite loop.
could you suggest me why my filter is not working?
Thanks,
sathish
Background:
I am trying to upload data from a simple on off sensor to learn the Xively methods. I am using an Arduino Uno with a WiFi Shield. I made some simple alterations to an example sketch from the Xively library to keep it very simple. I have read the documentation and the FAQ's plus searched the web. There was a similar question (Can't connect to Xively using Arduino + wifi shield, "ret = -1 No sockets available) and the answer was to reduce the number of libraries loaded. I'm using the same library list recommended in that post.I have also updated my Arduino IDE and downloaded the latest xively and HTTP library. The code compiles without error. I re-loaded my device on the xively website and got a new API key and number as well. Plus, I ensured the channel was added with the correct sensor name. I have also checked my router and ensured the WiFi shield was connecting properly.
Problem: I can't see the data on the Xively website and I keep getting the following error messages on the serial monitor from the Arduino:
xivelyclint.put returned -1
also, after several tries, I get "No socket available"
Question: Is there an problem with the code or is it something else?
Current Arduino code (actual ssid, password and API key and number removed):
#include <SPI.h>
#include <WiFi.h>
#include <HttpClient.h>
#include <Xively.h>
char ssid[] = "ssid"; // your network SSID (name)
char pass[] = "password"; // your network password (use for WPA, or use as key for WEP)
int keyIndex = 0; // your network key Index number (needed only for WEP)
int status = WL_IDLE_STATUS;
// Your Xively key to let you upload data
char xivelyKey[] = "api_key";
// Analog pin which we're monitoring (0 and 1 are used by the Ethernet shield)
int sensorPin = 2;
// Define the strings for our datastream IDs
char sensorId[] = "sensor_id";
XivelyDatastream datastreams[] = {
XivelyDatastream(sensorId, strlen(sensorId), DATASTREAM_INT),
};
// Finally, wrap the datastreams into a feed
XivelyFeed feed(feed no., datastreams, 1 /* number of datastreams */);
WiFiClient client;
XivelyClient xivelyclient(client);
void printWifiStatus() {
// print the SSID of the network you're attached to:
Serial.print("SSID: ");
Serial.println(WiFi.SSID());
// print your WiFi shield's IP address:
IPAddress ip = WiFi.localIP();
Serial.print("IP Address: ");
Serial.println(ip);
// print the received signal strength:
long rssi = WiFi.RSSI();
Serial.print("signal strength (RSSI):");
Serial.print(rssi);
Serial.println(" dBm");
}
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
Serial.println("Starting single datastream upload to Xively...");
Serial.println();
// attempt to connect to Wifi network:
while ( status != WL_CONNECTED) {
Serial.print("Attempting to connect to SSID: ");
Serial.println(ssid);
status = WiFi.begin(ssid, pass);
// wait 10 seconds for connection:
delay(10000);
}
Serial.println("Connected to wifi");
printWifiStatus();
}
void loop() {
int sensorValue = digitalRead(sensorPin);
datastreams[0].setInt(sensorValue);
Serial.print("Read sensor value ");
Serial.println(datastreams[0].getInt());
Serial.println("Uploading it to Xively");
int ret = xivelyclient.put(feed, xivelyKey);
Serial.print("xivelyclient.put returned ");
Serial.println(ret);
Serial.println();
delay(15000);
}
One day I was playing around with my Arduino and had a cool idea. Maybe I could do a wireless connection WITHOUT the serial monitor! I could use an LCD display instead! So, I went to work. I replaced all of the serial stuff with LCD stuff.
Finally I had no errors in my code (according to the Arduino client, that is).
Here is my code:
#include <LiquidCrystal.h>
#include <WiFi.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
char ssid[] = "Fake Network"; // Your network SSID (name)
char key[] = "1"; // your network key
int keyIndex = 0; // Your network key Index number
int status = WL_IDLE_STATUS; // The Wi-Fi radio's status
void setup() {
lcd.begin(16, 2);
// Check for the presence of the shield:
if (WiFi.status() == WL_NO_SHIELD) {
lcd.println("WiFi shield not present");
// Don't continue:
while(true);
}
// Attempt to connect to Wi-Fi network:
while ( status != WL_CONNECTED) {
lcd.print("Attempting to connect to WEP network, SSID: ");
lcd.println(ssid);
status = WiFi.begin(ssid, keyIndex, key);
// Wait 10 seconds for connection:
delay(10000);
}
// Once you are connected:
lcd.print("You're connected to the network");
printCurrentNet();
printWifiData();
}
void loop() {
// Check the network connection once every 10 seconds:
delay(10000);
printCurrentNet();
}
void printWifiData() {
// Print your Wi-Fi shield's IP address:
IPAddress IPaddr = WiFi.localIP();
lcd.print("IP Address: ");
lcd.println(IPaddr);
lcd.println(IPaddr);
// Print your MAC address:
byte MACaddr[6];
WiFi.macAddress(MACaddr);
lcd.print("MAC address: ");
lcd.print(MACaddr[5],HEX);
lcd.print(":");
lcd.print(MACaddr[4],HEX);
lcd.print(":");
lcd.print(MACaddr[3],HEX);
lcd.print(":");
lcd.print(MACaddr[2],HEX);
lcd.print(":");
lcd.print(MACaddr[1],HEX);
lcd.print(":");
lcd.println(MACaddr[0],HEX);
}
void printCurrentNet() {
// Print the SSID of the network you're attached to:
lcd.print("SSID: ");
lcd.println(WiFi.SSID());
// Print the MAC address of the router you're attached to:
byte bssid[6];
WiFi.BSSID(bssid);
lcd.print("BSSID: ");
lcd.print(bssid[5],HEX);
lcd.print(":");
lcd.print(bssid[4],HEX);
lcd.print(":");
lcd.print(bssid[3],HEX);
lcd.print(":");
lcd.print(bssid[2],HEX);
lcd.print(":");
lcd.print(bssid[1],HEX);
lcd.print(":");
lcd.println(bssid[0],HEX);
// Print the received signal strength:
long rssi = WiFi.RSSI();
lcd.print("signal strength (RSSI):");
lcd.println(rssi);
// Print the encryption type:
byte encryption = WiFi.encryptionType();
lcd.print("Encryption Type:");
lcd.println(encryption,HEX);
lcd.println();
}
And the result was....... Nothing. Nothing displayed.
Then I went and did my version of debugging. Note that I started at the bottom of the code.
lcd.print("bug");
I put this under every line of my code. Finally, I got to the top, under this line:
lcd.begin(16, 2);
AND GUESS WHAT! No display in any of the lines! I looked everywhere and I checked the display pins.
FINALLY, I found the problem!
It's a horrible bug that I can't get rid of! The display won't show with the WiFi.h library! I don't know why, But if I even #include <WiFi.h> into my program (or any program with the LiquidCrystal library... Things go exactly the same way!
What is the reason for this problem and how can I fix it? I haven't got any luck yet.
According to the documentation:
Arduino communicates with both the Wifi shield's processor and SD card using the SPI bus (through the ICSP header). This is on digital pins 11, 12, and 13 on the Uno and pins 50, 51, and 52 on the Mega. On Uno 11 is MOSI, and 12 is MISO.
According to your code
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
you are using pins 11 and 12 for the LCD. Now if the LCD was using SPI, then the LCD could share pins 11 and 12 with the Wi-Fi shield, because the same set of pins used for SS (Slave Select) function would tell the peripherals which one of them should be listening. However, the LiquidCrystal library uses its first two argument pins for RS and Enable respectively, making it incompatible with SPI. The solution: move your LCD onto different pins.