MySQL Forums - Connector/Arduino

Issue with update operation in the database table (1 reply)

Ramesh Damor — Mon, 12 Oct 2020 15:55:08 +0000

Hello,

I am facing an issue with update operation in the database table. Sometimes update query is not getting success and the MySql library (MySQL_MariaDB_Generic) on the gateway side is showing the error “MySQL_Packet::read_packet: ERROR: Timeout waiting for client".

I am using the AWS RDS server for the MYSQL database. MYSQL version is 8.0.20. And the query is executed from the ESP32 Wi-Fi module.

From my gateway application, I am inserting the data in 3 steps for 3 data fields as data size is large (around 10k). First I am inserting a record and then adding more data through the update query. The Insert query is successful every time but the update query fails sometimes even though I retry 10 times continuously.

The issue is not happening always. it is happening randomly. Sometimes it is working fine for around 7 to 8 hours before it starts misbehaving again.

It seems like the server is not responding. For debugging purpose I checked the process list on the Database server by executing the query “show processlist;" and I found that there are multiple processes for the same query with state “updating”. It could be due to multiple retries from the gateway. I am not able to follow that whether it is expected behavior (multiple same queries with state “updating”) or not.

We would like to understand why this is happening only sometimes and not always, and how does it recover? Are there any contributing factors from the server-side for this behavior? Are there any configurations that we need to do on our side? Any guidance is appreciated on this.

For your information:

I have used the MySQL_MariaDB_Generic library on the ESP32 Wi-Fi module to send data to the database. Database table contains 7 data fields like Id,Timestamp,P1,P2,P3,P4,and P5. Here ‘Id ‘ is the primary key and Autoincrement attribute.

Here datatypes for the data fields P3, P4, and P5 are MEDIUMBLOB.

Query to insert data fields Timestamp, P1, P2, P3: INSERT INTO TabelXYZ(Timestamp, P1, P2, P3)VALUES ('TimestampValue','P1Value','P2Value','P3Value');

query to insert data field P4: UPDATE TabelXYZ SET P4 = 'P4Value' WHERE Timestamp = 'TimestampValue' ORDER BY Timestamp;

query to insert data field P4: UPDATE TabelXYZ SET P5 = 'P5Value' WHERE Timestamp = 'TimestampValue' ORDER BY Timestamp;

Please note that there is no internet connectivity issue here as the insert query is executing OK every time and only the update query is getting failed.

I am not able to find any root cause behind it. Let me know if anyone has suggestions/idea about what I am doing wrong.

MySQL_Connector with Realtek Ameba WIFI (2 replies)

L Prong — Mon, 20 May 2019 19:05:55 +0000

I recently installed MySQL in a Windows environment.
I have extensive db programming experience (long ago), but new to this server setup, admin, etc.

I can connect to my server using a second computer on my local wifi network, however when I use the same credentials in a Sample Arduino MySQL_connector WIFI sketch, the Ameba connects to the WIFI successfully, but then I receive a message that says "Connect to Server successful!".

This message is not coming from the sketch. Furthermore, the program stalls at that point and no additional commands are performed. MySQL Workbench does not show a client connection for the User in the Arduino sketch.

Combing the internet has not revealed any solutions.

Thoughts?

Arduino IDE and MYSQL_Connector library (2 replies)

Gwyllym Jones — Mon, 13 May 2019 16:01:28 +0000

Question: Is there a limit in the size of query that can be returned using the MYSQL_Connector library for the Arduino IDE?

Background: I am trying to access a field in a MYSQL database table which is approx 2Kb in size. I'm using the Arduino MYSQL_Connector library and for testing purposes have simplified the field so that it only contains the character 'a', i.e there are no special characters or escape characters in the data. Experimenting with the field size (i.e no. of characters) results in the following:

Field size Returned data size from Query
<=250 <=250
>=251 and <=255 1
=256 0
>256 252

In all cases, the query returns the initial characters from the field, anything after character# 252 is being truncated.

If I run the query using mysql cli client, Dbeaver or MySQL Workbench I get the full field contents returned in the query exactly as expected.

I've read that truncation can occur if charsets between the server and client do not match and have experimented using different CHARSET and COLLATE options on the server (utf8,utf8mb4, Latin1) etc. but it doesn't change the output results described above.

Has anyone else seen this behaviour or know what I am doing wrong?

Additional info:

The test script is pretty much taken straight from the examples that are provided with the library i.e.
-----------------
char query[1000] = "SELECT myData FROM myTable WHERE myId = 'esp14c8dd';";

WiFiClient client;
MySQL_Connection conn((Client *)&client);

void setup() {
Serial.begin(115200);
WiFi.mode(WIFI_STA);
WiFi.disconnect();
delay(100);
WiFi.begin(ssid, wifiPass);

while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.print(".");
}
Serial.println();
if (conn.connect(server_addr, 3306, user, password)) {
delay(1000);
}
else
Serial.println("Connection failed.");
}

void loop() {
delay(1000);

// Initiate the query class instance
MySQL_Cursor *cur_mem = new MySQL_Cursor(&conn);

// Execute the query
cur_mem->execute(query);

delay(2000);
// Fetch the columns and print them
column_names *cols = cur_mem->get_columns();
for (int f = 0; f < cols->num_fields; f++) {
Serial.print(cols->fields[f]->name);
if (f < cols->num_fields-1) {
Serial.print(',');
}
}
Serial.println();
// Read the rows and print them
row_values *row = NULL;
do {
row = cur_mem->get_next_row();
if (row != NULL) {
for (int f = 0; f < cols->num_fields; f++) {
Serial.println(row->values[f]);
Serial.printf("Size of data is %lu\n",strlen(row->values[f]));
//Serial.println(strlen(row->values[f]));
if (f < cols->num_fields-1) {
Serial.print(',');
}
}
Serial.println();
}
} while (row != NULL);
// Deleting the cursor also frees up memory used

delete cur_mem;
}
-------------------------

MySQL Community Server v8.0.15 for Linux on x86_64
NodeMCU v3 ESP8266
Arduino IDE v1.8.9
MYSQL_Connector library v1.1.1

Can i use ESP8266-01 with Connector (1 reply)

ROBSON ANDRADE — Mon, 13 May 2019 15:56:12 +0000

Can i use ESP8266-01 with Connector? How do it?

MySQL 8.0 on ARM64 (no replies)

Edwin Desouza — Mon, 25 Jun 2018 04:59:39 +0000

MySQL 8.0 on Oracle Linux on ARM64:
- https://blogs.oracle.com/wim/oracle-linux-7-for-arm-is-now-generally-available
- https://blogs.oracle.com/linux/announcing-the-general-availability-of-oracle-linux-7-for-arm
- https://docs.oracle.com/cd/E52668_01/E97565/html/ol7-features-mysql.html

Arduino Serial Monitor Dependency (no replies)

Matha Goram — Fri, 16 Feb 2018 14:13:28 +0000

Thanks to Dr. Bell's library and documentation, I have achieved my initial goal to log telemetry from a MKR1000 board to a networked MySQL instance while the board is anchored to a desktop. I do not have any calls to the Serial library in my code but, of course, the MySQL connector logs the connection to the Serial Monitor which has to be kept open for this message to be logged. If the Serial Monitor window is not opened on the desktop, the Arduino sketch appears to be hung.

While I can live with this arrangement (i.e. Arduino board anchored to desktop) for testing purposes, I would really like to run these MKR1000 boards in untethered mode without any ability to display the Serial Monitor window. Unfortunately, when I attempt to do just that, the sketch never logs any INSERTs to the MySQL instance (my only way, to the best of my knowledge, to recognize silently that the sketch is running).

I need some guidance on how to run the MKR1000 independently with the MySQL Arduino connector fully capable to perform all the operations that Dr. Bell has kindly made available. This issue may be a general Arduino topic but since the initial connection message is from the MySQL Connector I feel that my first attempt should be in this forum. (Of course, my knowledge of Arduino too is very limited!). I feel that the MySQL Connector/Arduino is very powerful and I would like to get with more robust exercises if I am improve my basic understanding of the underlying operations. Thanks.

Poor performance inserting records into a table (4 replies)

Brian Nickels — Thu, 08 Feb 2018 11:28:40 +0000

I am running the Arduino version of the MySQL connector and noticed it took 13 seconds to post an insert statement into a MySQL table. The insert statement is:

INSERT INTO weather_vers1.sensor_reading (measurement, reading, unit_of_measure, sensor_id, metric) VALUES ('T',73.9,'F',3237464,0),('H',47.4,'RH',3237464,0),('P',28.87,'HG',3237464,0),('D',52.6,'F',3237464,0)

I ran a network trace and found out the ESP8266 is sending the insert statement one character at a time. Below is a chopped down version of the trace. Notice the payload length is 1 for all ESP to MySQL conversations while the final response from the server is 53 bytes acknowledging that 4 records were inserted.

SEQ Offset Source Destination Prot Payload
1374 25.9254442 ESP-8266 MySql Server TCP PayloadLen=1,
1377 25.9767419 MySql Server ESP-8266 TCP PayloadLen=0,
1378 25.9789536 ESP-8266 MySql Server TCP PayloadLen=1,
1379 26.0391143 MySql Server ESP-8266 TCP PayloadLen=0,
1382 26.0411178 ESP-8266 MySql Server TCP PayloadLen=1,
1383 26.0420829 MySql Server ESP-8266 TCP PayloadLen=53,

The relevant portions of my code are:

char* INSERT_SQL = "INSERT INTO weather_vers1.sensor_reading (measurement, reading, unit_of_measure, sensor_id, metric) VALUES ('%s',%s,'%s',%d,%d),('%s',%s,'%s',%d,%d),('%s',%s,'%s',%d,%d),('%s',%s,'%s',%d,%d)";
MySQL_Connection conn((Client *)&client);
if (conn.connect(server_addr, 3306, user, password)) {
delay(1000);
Serial.print("Connection Status: ");
Serial.println(conn.connected());
}
else
Serial.println("Connection failed.");

MySQL_Cursor *cur_mem = new MySQL_Cursor(&conn);

sprintf(query, INSERT_SQL, "T", tempStr, "F", id, 0, "H", humStr, "RH", id, 0, "P", presStr, "HG", id, 0, "D", dewPointStr, "F", id, 0);

cur_mem->execute(query);
delete cur_mem;

My question becomes, Is this how the connector is suppose to work or am I doing something wrong?

Error while insert data Into table (1 reply)

POKHRAJ Das — Wed, 29 Nov 2017 15:50:23 +0000

Hi,
I am facing error while inserting data into table...
The below is my table structure..

==================
create table arduino (arvalue double(10,2));
======

Now when I am trying to insert data from vb.net it is throwing error..

"Excption: Thrown You have an error in sql syntax.
===========
But when manually I am trying to insert from mySQL workbench, it is working fine.

=============
Below is my sql syntax from vb.net.....

Dim readserialdata As String
Dim sqlquery As String
Dim cmd As New MySqlCommand
readserialdata = myport.ReadLine()
Label1.Text = readserialdata
sqlquery = "insert into tab1 values(" & Trim(readserialdata) & ")"
cmd = New MySqlCommand(sqlquery, cn)
cmd.ExecuteNonQuery()

CC3000 (1 reply)

Shaun van Wyngaard — Thu, 06 Jul 2017 13:25:33 +0000

I see back in 2014 you decided not worth updating code to support this board.
Unfortunately I didn't do enough research before I saw this topic.
3 years later, is that still the decision?

I use MySQL connectorl and after some time it stops. PLEASE HELP (13 replies)

César Sebastián Silva Proaño — Thu, 20 Apr 2017 17:39:42 +0000

Dear gentlemen of the MySQL forum I hope you can help me with this problem

I am using an arduino atmega2560, a wifi shield and a dust sensor (dsm501a) for a project. I have to translate the measurements from my sensor to a mysql data base. I used the mySQL connector created by Dr. Charles Bell. When I see that the blue DATA led of the wifi shield blinks it is because the data is being translated from the sensor to the mySQL data base. Everything is working fine but suddenly at one point (sometimes 1 hour, sometimes 30 minutes) it stops blinking, my serial monitor paralyzes and no more data is transmitted. Could you please help me? What do I have to do? Do I need to add something in my code? This system is supposed to work 24 hours and the whole time saving the measurements from the sensor therefore it cannot stop.
Please I hope you can help me.
Best regards,
Sebastian Silva P.

Issue with NULL data in column (4 replies)

Tony Olivieri — Tue, 25 Oct 2016 18:19:15 +0000

Good Day, using Arduino MySQL Connector ver 1.0.4 on Adafruit ESP8266 HUZAH. Data table set up with 12 columns, several which allow NULL's. Code is based upon the 'Basic Select Example'. When data returned contains NULL data in a column I get unexpected result shown below:

Running SELECT and printing results

SELECT TimeBased, collFrequency, collDuration, A_Time_HR, A_Time_MIN, B_Time_HR, B_Time_MIN, C_Time_HR, C_Time_MIN, CycleSync FROM mqttData.deviceParms WHERE devID = '1234'
1,3600,25,16,0,?0?0û?1m!???3600,Time_HR, B_Time_MIN, C_Time_HR, C_Time_MIN, CycleSync FROM mqttData.deviceParms WHERE devID = ',234',ÿ?Ä?ÿ?¼ ,?ä?ÿ?$?ÿ?d?ÿ?¤?ÿ?ä?ÿ?$
ÿ?

If I populate null fields, I get data as expected shown below:

Running SELECT and printing results

SELECT TimeBased, collFrequency, collDuration, A_Time_HR, A_Time_MIN, B_Time_HR, B_Time_MIN, C_Time_HR, C_Time_MIN, CycleSync FROM mqttData.deviceParms WHERE devID = '1234'
1,3600,25,16,0,0,0,0,0,1

Is this behavior expected?

Thank you.

error 5 (7 replies)

Kurt Bierbaum — Tue, 19 Jul 2016 12:31:37 +0000

Hi Chuck,

I am running an Arduino project accessing a mysql database, connector version is 1.04ga. This is a nice solution.

However, I am encountering an "Error: 5 = ." when performing a select query like:

SELECT_QUERY [] = "SELECT * FROM plants.preferences WHERE tag = \"%s\""

This is not a big issue since the code continues to work, but I would like to know what is the reason.

Do you have any idea?

Thank you,
Kurt

Arduino UPDATE Mysql (6 replies)

Darci CIdade — Fri, 17 Jun 2016 13:07:33 +0000

Dear,

I need the Arduino make UPDATE in the database, for example:

When input HIGH the arduino, arduino send number 1 to the database.
When input LOW the arduino, arduino send number 0 to the database.

Need php program to make this change in mysql or is to make direct connection Arduino -> Database?

Every connection between Arduino and database is OK and running.

Thanks.

Insert data to a remote MySQL server?? (web-host MySQL) (1 reply)

Marmus man — Tue, 29 Mar 2016 17:57:08 +0000

I read in the intro paragraphs of the new .pdf (very useful, btw) that the Arduino must be connected to the same Network as the MySQL server.

Do you have any experience/suggestions/recommendations for connecting to a remote MySQL server? ...like a web-based MySQL database from a web-hosting company like HostGator?

I would like to Insert the data from my sensors to my web-based MySQL database and then present it as a "live" website to graph the data. This way I can collect data over several months without needing to leave a computer on. And I can access the graphed data from anywhere at anytime via the web.

Thanks in advance for any input you can give...

Marmusman

Put SELECT result into a variable (no replies)

Silvio Pedretti — Sat, 26 Dec 2015 20:12:26 +0000

Hello,

please help me with this (for me) big problem, I'm struggling trying to find a solution with no results.....

I have this part of code:

sprintf(query, SELECT_DATA);
my_conn.cmd_query(query);
column_names *cols = my_conn.get_columns();
Serial.println();
for (int f = 0; f < cols->num_fields; f++) {
Serial.print(cols->fields[f]->name);
if (f < cols->num_fields - 1)
Serial.print(',');
}
Serial.println();
row_values *row = NULL;
while (row = my_conn.get_next_row()) {
for (int f = 0; f < cols->num_fields; f++) {
Serial.print(row->values[f]);
if (f < cols->num_fields - 1)
Serial.print(',');
}
my_conn.free_row_buffer();
Serial.println();
}

It works, I can read from the serial monitor the results of the query, but I don't know how to put them into a variable...

any help is much appreciated...

thank you

Code hangs in cmd_query() (no replies)

Dag Hovden — Thu, 03 Dec 2015 13:23:18 +0000

Hello,

I have a sketch running on an Adafruit Huzzah ESP8266 board (using ESP8266WiFi.h instead of WiFi.h), collecting some data and sending the data to a MySQL database in my local network, the latter using the mysql_connector. The insert query typically looks like this

INSERT INTO datalog.datalogmeasdata (UserID,Date,Time,MeasValID,MeasVal) VALUES (1,'2-12-2015','10:15:46',2,436)

Normally, it takes about 20-25 sec to execute which is quite long but not a problem, the data collected doesn't change all that fast anyway.

However, at times the code never returns from the cmd_query() calls and I have to reset the Huzzah to get the sketch running again. This can happen after 15 minutes or after 9 hours, seems quite random to me. The database is still there, that I can check from my local PC.

Is there way to specify a timeout value for cmd_query() and get it to return an error code when the query fails?

I have had a look at the code but not in any depth. There seems to be some waiting going on but only if WiFi is not defined (i.e. using Ethernet) which I don't really understand.

Anyway, grateful for any suggestions, pointers, ideas :-)

Regards,
Dag

MySQL connector arduino (3 replies)

Ole Chr Pettersen — Tue, 01 Dec 2015 19:07:14 +0000

Hi

im having coding problems connecting an temperature sensor too the MySQL.
The trouble is defining the code for the sensor.
it's the Ds1820 temp sensor.

"
celsius = (float)raw / 16.0;
fahrenheit = celsius * 1.8 + 32.0;
Serial.print(" Temperature = ");
Serial.print(celsius);
Serial.print(" Celsius, ");
Serial.print(fahrenheit);
Serial.println(" Fahrenheit");
char query[64];
sprintf(query, INSERT_DATA, celsius);
my_conn.cmd_query(query);
}
"

loop speed (2 replies)

Silvio Pedretti — Mon, 14 Dec 2015 20:33:12 +0000

I would like to use arduino and mysql for a domotic project.
I got it all work, but I find it too slow in the response.
In the sketch I am posting, the SELECT query is done every 1 second.
Is there any way to better the speed?

Thank you

#include "SPI.h"
#include "Ethernet.h"
#include "sha1.h"
#include "mysql.h"

byte mac_addr[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress server_addr(192, 168, 10, 13);

Connector my_conn;

char user[] = "arduino";
char password[] = "psw";
int num_fails;
int MAX_FAILED_CONNECTS = 10;
int last_value = 0;
const char QUERY_POP[] = "SELECT last_value FROM test_arduino.sensor WHERE sensor_num = 1";
char query[128];

const int relay_pin = 5;

void setup() {
digitalWrite(relay_pin, HIGH);
pinMode(relay_pin, OUTPUT);
Ethernet.begin(mac_addr);
Serial.begin(115200);
if (my_conn.mysql_connect(server_addr, 3306, user, password)) {
delay(500);
Serial.println("Success!");
} else {
Serial.println("Connection failed.");
}
}

void soft_reset() {
asm volatile("jmp 0");
}

void loop() {
{

my_conn.cmd_query(QUERY_POP);
my_conn.get_columns();
row_values *row = NULL;
do {
row = my_conn.get_next_row();
if (row != NULL) {
last_value = atol(row->values[0]);
}
} while (row != NULL);
my_conn.free_columns_buffer();
my_conn.free_row_buffer();

if (last_value == 1) {
digitalWrite(relay_pin, LOW);
} else
digitalWrite(relay_pin, HIGH);

}
}

mysql connector for PIC32 (chipkit) and TI's arm TIVA C TM4C129 (10 replies)

Alok Kumar Mishra — Wed, 16 Mar 2016 09:10:22 +0000

Hello,

I have ported arduino mysql connector to chipkit ( PIC32 ) and verified that mysql c connector works,also it works for TI's arm TIVA C TM4C129

how do I load image(binary) files from mysql server to arduino (3 replies)

Alok Kumar Mishra — Tue, 01 Dec 2015 19:17:25 +0000

I have a arduino (DUE and uno) and I am successfully using arduino mysql connector , now want to display image (bmp) files from mysql server, How can I do that, so far I see it is assumed that strings (which are retrieved) are null terminated.

-Thanks
-Alok

Read values float from mysql (2 replies)

Denys Oliveira — Thu, 20 Aug 2015 15:09:44 +0000

Hello!
I need read a value float from my data base.
I using this code from a example(I changed only the select)
But I could only read the whole of the value and I need the two decimal places

value displayed in serial monitor = 127

necessary value = 127.62

anybody can help me?

/**
* Example: Simple Select Example: Hello, MySQL!
*
* This code module demonstrates how to create a simple
* database-enabled sketch with selecting data.
*/
#include
#include
#include
#include
/* Setup for Ethernet Library */
byte mac_addr[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress server_addr(192, 168, 0, 103);
/* Setup for the Connector/Arduino */
Connector my_conn; // The Connector/Arduino reference
char user[] = "operador";
char password[] = "secret";
const char QUERY_POP[] =
"SELECT tensao FROM banco.hello WHERE id = (SELECT MAX(id) FROM banco.hello)";
float head_count = 0;
void setup() {
Ethernet.begin(mac_addr);
Serial.begin(115200);
while (!Serial);
delay(1000);
Serial.println("Connecting...");
if (my_conn.mysql_connect(server_addr, 3306, user, password)){
Serial.println("Connected!");
my_conn.cmd_query(QUERY_POP);
my_conn.get_columns();
row_values *row = NULL;
do {
row = my_conn.get_next_row();
// We use the first value returned in the row - population of NYC!
if (row != NULL) {
head_count = atol(row->values[0]);
}
my_conn.free_row_buffer();
} while (row != NULL);
my_conn.free_columns_buffer();
Serial.print("ultima tensao = ");
Serial.println(head_count);
} else {
Serial.println("Connection failed.");
}
}
void loop() {
}

Trouble Getting mysql connection. (1 reply)

Aaron Ang — Fri, 14 Aug 2015 14:00:54 +0000

So I've been trying to use the connected and I've used ipconfig to get my IP address of my database and i've entered the following code to try and push a simple "hello" onto my database but I keep getting the message

Connecting...
Connection failed.

Here's my current code.

/**
* Example: Insert Example: Hello, MySQL!
*
* This code module demonstrates how to create a simple
* database-enabled sketch with inserting data.
*/
#include "SPI.h"
#include "Ethernet.h"
#include "sha1.h"
#include "mysql.h"
/* Setup for Ethernet Library */
byte mac_addr[] = { 0x90, 0xA2, 0xDA, 0x0F, 0x3A, 0xDC };
IPAddress server_addr(192,168,1,240);
/* Setup for the Connector/Arduino */
Connector my_conn; // The Connector/Arduino reference
char user[] = "ang";
char password[] = "";//myset password
char INSERT_SQL[] =
"INSERT INTO test_arduino.hello_arduino (message) VALUES ('Hello, Arduino!')";
void setup() {
Ethernet.begin(mac_addr);
Serial.begin(115200);
while (!Serial);
delay(1000);
Serial.println("Connecting...");
if (my_conn.mysql_connect(server_addr, 3306, user, password)){
Serial.println("Connected!");
my_conn.cmd_query(INSERT_SQL);
Serial.println("Data inserted.");
} else {
Serial.println("Connection failed.");
}
}
void loop() {
}

editing database data from arduino (2 replies)

Jimmy T — Wed, 18 Feb 2015 18:13:30 +0000

Dr. Bell
Thanks for the book, worth every penny!
I've spent the last few days working on setting up the pi and arduino, everything is working great! i did get hung up on the "with select" part because i was using querys and editing the my.cnf file (raspberry pi permissions were a pain), just an fyi.

So now the arduino is displaying information from a specific cell (in a table) on an lcd screen.... how would i go about updating that specific value, i can add data to a list but not update a specific cell.... any advice? i will work on this tomorrow so i may wind up answering my own question but any help would be great!

for any other beginners out their lookup mysql in excel.... it has been really handy for viewing and creating data for the arduino to edit/lookup. dont have to mess around on the pi plus easy to edit and analyze!

Thanks everyone

Arduino MySQL Connector Select Query- How to access individual values (2 replies)

Patrick LAFFORGUE — Mon, 02 Feb 2015 20:14:19 +0000

Hello,

thanks for this helpfull and usefull Arduino MySQL Connector.
I try to command LEDs on an Arduino board from a HTML page using a PHP script and a MySQL Database. I succeed in updating the MySQL Database, reading it with Arduino board and displaying the pin states on the serial monitor. But I didn't succeed in accessing the individual pin state. Where is my mistake ?

Thanks in advance for your help.

Best regards.

Here is the concerned part of the code :

int Pin0, Pin1, Pin2, Pin3, Pin4, Pin5 ;

.......

if (r)
{
rows++;
for (int i = 0; i < num_cols; i++)
{
Serial.print(r->values);

if (i == 0) Pin0 = atoi(r->values[0]) ;
if (i == 1) Pin1 = atoi(r->values[1]) ;
if (i == 2) Pin2 = atoi(r->values[2]) ;
if (i == 3) Pin3 = atoi(r->values[3]) ;
if (i == 4) Pin4 = atoi(r->values[4]) ;
if (i == 5) Pin5 = atoi(r->values[5]) ;
else break ;
}

my_conn.free_row_buffer(); // Free the row buffers
}
} while (r);

Serial.println() ;
Serial.print(rows);
Serial.println(" rows in result");

Serial.println(Pin0);
Serial.println(Pin1);
Serial.println(Pin2);
Serial.println(Pin3);
Serial.println(Pin4);
Serial.println(Pin5);

Problem building (21 replies)

Carl Engman — Thu, 26 Mar 2015 13:57:27 +0000

Hi

Getting this error during build. Any idea?

In file included from /Users/carl/Documents/Arduino/libraries/sha1/sha1.cpp:3:0:
/Users/carl/Documents/Arduino/libraries/sha1/sha1.cpp:11:25: error: variable 'sha1InitState' must be const in order to be put into read-only section by means of '__attribute__((progmem))'
uint8_t sha1InitState[] PROGMEM = {

stringf and float (4 replies)

achim altmann — Wed, 07 Jan 2015 14:41:48 +0000

Hello,

work the mysql-string only with stringf ?

i have a lot of float types and i am not sure if i need stringf or ???

Best regards
Achim

SHA problem (1 reply)

Lucas Lima — Wed, 12 Nov 2014 14:10:42 +0000

I'm also new at this...
I'll be simple...I'm getting this error message

In file included from /usr/share/arduino/libraries/sha1/sha256.cpp:3:0:
/usr/share/arduino/libraries/sha1/sha256.cpp:8:20: error: variable ‘sha256K’ must be const in order to be put into read-only section by means of ‘__attribute__((progmem))’
uint32_t sha256K[] PROGMEM = {
^
/usr/share/arduino/libraries/sha1/sha256.cpp:21:27: error: variable ‘sha256InitState’ must be const in order to be put into read-only section by means of ‘__attribute__((progmem))’
uint8_t sha256InitState[] PROGMEM = {
^

not much ideia of what is it, and kind of afraid of changing files without knowning better what's happening...

any ideias? Thanks

Query Results as String (1 reply)

Jon Chambers — Wed, 29 Oct 2014 18:29:13 +0000

Hi.

I'm creating a project where I want to interpret the incoming values from a database as blinking lights (morse code).

I've got your example code working, using Example 2, but am having trouble figuring out how to use the results that are printed out in the serial monitor as strings in order to write a conditional to check for specific characters in the string.

I want to do something like this:

If (InTheDatabaseResults == ‘character’) {

blinking code here

}

I’ve tried using the Serial.read(r->values) instead of Serial.print, but get errors. Also writing a conditional like the one above with the r->values, but that doesn’t work either.

How can I get/convert the text in order to compare the characters?

Sorry if the answer is obvious, I just can’t figure this out.

Helps to achieve connect (1 reply)

Miguel martinez — Tue, 14 Oct 2014 20:09:41 +0000

Now I have the information of my sensors, I only need to pass it to mysql.

This is my try sketch:

#include "SPI.h"
#include "Ethernet.h"
#include "sha1.h"
#include "mysql.h"

/* Setup for Ethernet Library */
byte mac_addr[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192, 168, 1, 10);
IPAddress gw(192, 168, 1, 1);
IPAddress sn(255, 255, 255, 0);

IPAddress server_addr(192, 168, 1, 3);

/* Setup for the Connector/Arduino */
Connector my_conn; // The Connector/Arduino reference

char user[] = "root";
char password[] = "" ;
char INSERT_SQL[] = "INSERT INTO shop.data VALUES ('Hello, MySQL!', 77)";

void setup() {
Serial.begin(115200);
}

void loop() {
Ethernet.begin(mac_addr,ip,gw,sn);
Serial.print("Local IP is: ");
Serial.println(Ethernet.localIP());
delay(1000);
Serial.println("Connecting...");
if (my_conn.mysql_connect(server_addr, 3306, user, password))
{
delay(500);
/* Write Hello, World to MySQL table test_arduino.hello */
my_conn.cmd_query(INSERT_SQL);
Serial.println("Query Success!");
}
else
Serial.println("Connection failed.");
}

... But the serial monitor only says:
Connecting...
Connection failed.

There is something special to configure the mysql to accept the orders of the connector library?

Packet Error (9 replies)

Bryan Davis — Wed, 26 Nov 2014 16:14:19 +0000

I'm trying to do my first build using this library and am having problems.

I'm using an Uno R3 with the Ethernet Shield.

When I try to use your example script, with the correct username/password and IPAddress of my mySQL server, all I get is:

Connecting...
Packet error.

I know I'm getting connected properly, because in my version, I added some extra debugging to the serial output. Here's what my script comes up with:

CurrentMonitor is running at: 10.2.2.40
Connecting...
Packet error.
Packet error.
Error: 255 = .
Connection failed.
Packet error.
Packet error.
Packet error.
Memory error.

I can ping the IP of the Uno from another computer (which means it's on the network) and can also get into the mySQL server from the GUI Workbench using the exact same IPAddress, User, and Password from the computer in which I'm programming the Uno from.

But like I said, even using your example "mysql_connector_basic", I get the error as stated above after only changing the mac, IPAddress and user/password.

So I really don't think it's a network issue.

Any thoughts?