many thanks

hue = 127;

any ideas why something like this does not work:

hue 127;

blinkm_script_line script1_lines[] = {
  {1,  {'f', 10, 00, 00}},
  {25, {'h', hue, 0xff, 0xff}},  // Custom Color
  {25, {'h', 43, 0x00, 0xff}},  // Bright White
};

If I replace hue inside the array with a number it works fine…been scratching my head about this for awhile now.

Hope you can help,
-G

With the traditional Arduino, SDA & SCL due double duty with Analog In pins 4 & 5. On the Arduino MEGA, SDA & SCL have their own dedicated holes.

Now as to how many you BlinkMs you can control over these two pins, theoretically it’s up to 120. In practice you start to run into issues with cable length and power requirements (each BlinkM can draw up to 60mA of current, and a USB-powered Arduino can supply about 450mA of current)

I’ve regularly driven 8 BlinkMs off a USB-powered Arduino on a 3-ft cable. My BlinkM Cylon project used 13 BlinkMs on a 6-ft cable.

I was just wondering.. if I get a Arduino Mega.. how many BlinkMs could I connect directly to it?

Also I want to be able to place BlinkMs along a meter long box, with the arduino situated at the back of it. Is this possible? Do I just need long wires from the BlinkMs connecting directly to the to Analog Ins on the Arudino Mega?

Many thanks!

As for reprogramming scripts 1-16, the short answer is “no, not yet”. A more detailed answer is here: http://getsatisfaction.com/thingm/topics/re_program_scripts_1_through_16

I just put 2 BlinkM-s as headlights / moodlights / statuslights on my BS2Px based robot and my kids are going nuts with it.

Forgive me if I missed the discussions on this – did you make changes to the firmware that allow us to re-program all 16 scripts, or we’re still at script 0 only?

Thanks for making one of the most fun little gadgets ever (I’m also waiting for my Max, this will be used with a pot to create mood light in a room…)

There are a variety of issues when dealing with large numbers of I2C devices. One is, as you guessed, that standard I2C has a 7-bit address space so can only address up to 127 devices (really around 100 due to some reserved addresses) The Arduino is a standard I2C master, so figure 100 BlinkMs per Arduino. The Arduino really has no provision for multiple I2C buses. There are ways around this, like with I2C bus switching chips, but can get complex. But with 100 BlinkMs/Arduino, you’d be controlling 10 Arduinos, which can be done with a single PC pretty easily.

Another issue with large numbers of I2C devices is bus length (really, bus capacitance). As either the length of the bus increases or the number of devices increase, each device has to work a bit harder to wiggle the I2C signal lines. What you’ll see is as you add devices or increase the length of the cable, things will start getting flaky. I’ve only experimented with up to 24 BlinkMs on a 30 foot cable. (I can never keep enough in-house to try out a larger experiment) There are I2C bus driver chips to help out with this issue. I’ve been meaning to investigate these chips to once and for all solve the “long BlinkM cable” question.

Or, would you reccoment a better way to run all of the individual BlinkM’s? The color patterns are not too precise but I would like to at least have some control over them.