blinkm addressing problem.. (try it on your blink)

hi everyone,

so i am having an issue trying to readdress a blinkM, i've also tried on a MaxM, but i would guess the firmware is the similar to a point.

so, i started with my own bit of code to sort out what i knew and didnt know about i2c, a fair bit - but i can write to the blink's with no problem. i have 3 pots hooked up and can control rgb directly. nothing new, i know, but it was an exercise.

so the next step is to control multiple blinks, independently. i can't get the addresses to stick though. here is my edited version of the stock code that is in the examples. i could be doing something silly, like sending hex instead of int, or something very strange could be going on... any help would be appreciated.

#include "Wire.h"
#include "BlinkM_funcs.h"

byte blinkm_addr = 0x08;
byte blinkm_globaladdr = 0x00;
int temp;

void setup() 



    Serial.print("Setting I2C address...");
    BlinkM_setAddress( blinkm_addr ); 
    Serial.println(blinkm_addr, HEX);
    Serial.print("Verifying I2C address, sent to 'correct' address...");

    temp = BlinkM_checkAddress( blinkm_addr ); //sent to what it should be


    Serial.print("Verifying I2C address, sent to global address...");
    temp = BlinkM_checkAddress( blinkm_globaladdr ); 

//sent to global, should return matching

    Serial.println("Did it work?");


void loop() 
    digitalWrite(13, HIGH); // flash Arduino LED for fun
    digitalWrite(13, LOW);

Thanks -- Jon :) continuation, i looked inside the blinkM_funcs.h and uncommented some of the debug messages, no change, still having an address problem.

here is the response, sorry it a bit of a mess

Setting I2C address...8
Verifying I2C address, sent to 'correct' address...received addr: 0x80
Setting I2C address...8
Verifying I2C address, sent to 'correct' address...received addr: 0x80
Verifying I2C address, sent to global address...No response, that's not good
Did it work?

and as a followup to my own post, hope this helps someone else...

haven't tried it yet, i'll give some feedback to see if it helps.

fail... :-(

i have 1.0c blinkm's anyone?


Have you tried using the “BlinkMTester” Arduino sketch that comes as part of the BlinkM Examples bundle? It has the ability to let you re-address BlinkMs and I use it all the time.

The home of the BlinkM Examples bundle lives here:
You can download the examples as a zip file here:
Or you can examine the source code to BlinkMTester here:

Let me know if BlinkMTester works. If it doesn’t, but otherwise the BlinkM appears to function, then you may have a bad BlinkM. We can arrange an exchange for you then.

HI Todd, thanks for the reply. The example does work, but i am getting strange results when i request the address. here is the output below.

Looking for a BlinkM: Device found at addr 2
Resetting address to default 9: 
Setting address to: 1
Address: -1

what do you think? is this normal, or something a bit strange? i can complete my project, but i think it’s odd that the firmware updater doesn’t work, nor when requesting an address, to get something meaningful back.


and... the last one...

it works, but i am really confused at "how" to send the addresses.

if the default address is 0x09, i would expect to change the address in a similar format - like 0x11, or 0x34. but if i write the destination address in that format - no luck, it doesn't work - if i write as plain 11 or 34, it works, so what is the " " or ' ' or 0x for??

byte blinkm1 = 11; //default is 0x09, re-addressed byte blinkm2 = 34;

thanks anyone for your help... _J