Python Tkinter Slider Widget write Value over I2C -

ok have been searching example while can not seem find examples of relaying tkinter slider values on i2c arduino. far have not tried communicate arduino yet. ill cross bridge next; want figure out how write slide widget values , send on i2c.

here simple gui slider widget in python 2 believe correct setup i2c communications. ive updated rpi set i2c well. want in arduino read values 0 180 servo control. important writes values or in way can used input. have other code in arduino drives same servo, if other conditions met , ignored.

from tkinter import* import rpi.gpio gpio import time  import smbus  bus = smbus.smbus=(1)  slave_address = 0x04    class app:        def __init__(self, master):          def sendscalereading(self):             s = scale.get()# how write , scale value , send it??                 bus(slave_address, ord('s'))#according example should                                          #"bus.write_byte(slave_address, ord('s'))"          frame = frame(master)         frame.pack()          scale = scale(frame, from_=0, to=180, orient=horizontal, command=sendscalereading)         scale.grid(row=1, column=1)    root = tk() root.wm_title('i2c servo control') app = app(root) root.geometry("200x50+0+0") root.mainloop()   

ok friend helped me out , wasnt far off. once got far small issue io error. getting [errno 5] io errors. make sure have ground connected between arduino , pi. when searched seemed overlooked many fixes out there offered. need sda, sla , gnd connected.

so anyways here code working running arduino i2c blink sketch. blink led on pin 13 faster or slower based on slider input in rpi on i2c. going try , write code control servo next , if successful post code.

rpi / python2 code below:

from tkinter import* import rpi.gpio gpio import time  import smbus  bus = smbus.smbus(1)  slave_address = 0x28    class app:        def __init__(self, master):          def sendscalereading(self):             s = scale.get()             print("we have" );             print( s )             bus.write_byte_data(slave_address, s, s )          frame = frame(master)         frame.pack()          scale = scale(frame, from_=0, to=180, orient=horizontal, command=sendscalereading)         scale.grid(row=1, column=1)    root = tk() root.wm_title('i2c servo control') app = app(root) root.geometry("200x50+0+0") root.mainloop()   

arduino i2c wire blink sketch below:

#include <wire.h> // unique address i2c slave device #define address 0x28   // constants won't change. used here  // set pin numbers: const int ledpin =  13;      // number of led pin  // variables change: int ledstate = low;             // ledstate used set led long previousmillis = 0;        // store last time led updated  // follow variables long because time, measured in miliseconds, // become bigger number can stored in int. volatile long interval = 1000;           // interval @ blink (milliseconds)  void setup() {   // set digital pin output:   pinmode(ledpin, output);         wire.begin(address);                // join i2c bus address #4    wire.onreceive(receiveevent); // register event   wire.onrequest(requestevent); // register request handler   }  //gets called when i2c read occurs void requestevent() { //any request data return 0x14 (random number picked testing)   wire.write( 0x14  ); }  // called when i2c write occurs void receiveevent(int howmany) { //just going support 1 byte commands   if (howmany  >0  ) {     int c = wire.read();     interval = c * 10;   }   while (wire.available() > 0 ) {     wire.read();   } }   void loop() {   // here you'd put code needs running time.    // check see if it's time blink led; is, if    // difference between current time , last time blinked    // led bigger interval @ want    // blink led.   unsigned long currentmillis = millis();    if(currentmillis - previousmillis > interval) {     // save last time blinked led      previousmillis = currentmillis;         // if led off turn on , vice-versa:     if (ledstate == low)       ledstate = high;     else       ledstate = low;      // set led ledstate of variable:     digitalwrite(ledpin, ledstate);   } }