Right now, I'd like to give out mad props to ThingM and todbot, without whom there would be no BlinkM, and the world (or at least youtube) would be a much less colourful place. The aim of this instructable is not to take business away from ThingM, in almost all cases I would encourage you to buy a blinkM or two if you need them in your project, but there are some reasons why it's good to have alternatives and these are the ones I'm thinking of:
- You need a lot of BlinkM's and can't afford to buy as many as you might need
- You have all the bits needed lying around, and loads of free time and solder to make them
- You like a bit of a challenge.
- The form factor of the BlinkM doesn't meet your projects requirements (ThingM also do a variant called the MinM)
- You are _really_ hung up about open source and want to stick it to the man.
So, The aims of this instructable will be to:
- Introduce the reader to CYZ_RGB, an open source RGB Pixel firmware based on BlinkM
- Show how to program the firmware onto a suitable Microcontroler
- Suggest a way for building the pixel, that doesn't use Proto or PCB boards
- Show how to use the Pixel.
Lets get started, gather your stuff.
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Signing UpStep 1: What you are going to need...
The parts list (BoM) for one Ghetto pixel looks like:
- 1x RGB LED (RapidOnline or ebay)
- 1x Atmel ATTiny45 (or tiny 44 or 85, ) (RapidOnline or ebay )
- 3x Resistors as per specifications of your LED data sheet (RadioShack / Maplin / Rapid / or similar to these [ebay]) probably 1/2 watt or less if you can find them. SMD if you are PRO ;)
- Some wire to connect the Pixel to your controller, and to string pixels together if you have more than one
Notes on the parts:
LED
I would recommend getting an RGB led in a single plastic housing. It would be possible to do this with three separate LEDs, but it would be more of a challenge to mix the colours well. You must avoid the RGB led's that you buy on ebay that are described as 'Slow Flash', 'Fast Flash', or 'Fade' as these have there own uC's built in, and while pretty, allow us no control over the colour. You can get 'manual control' RGB LED's that look like traditional 5mm domed LEDS, but with 4 or 6 legs, but these don't tend to be very bright. I would recommend getting LED's that are labled 'SuperFlux' or 'Piranha'. These are small square RGB LED's with four pins, and can be surprisingly bright for their size.
You also have a choice to make on Common Anode, or Common Cathode variants. All four pin RGB LEDs are made up of three individual 'dies' all in the same plastic housing, each 'die' gives off one colour, either Red, Green or Blue. Each 'die' has a positive (anode) and negative (cathode) supply. A common Anode LED has all three anodes linked together, and the three cathodes are separate. A Common Cathode LED has the opposite configuration, All three Cathode are linked together and the anode's are separate. The firmware that we are going to be using makes use of Common Cathode LED's, and it's probably best that you use those. However, I had a pile of superflux Common Anode LEDs, so I've modified the CYZ_RGB firmware to use common anode. I'll talk about this later, but i've only compiled and tested this modification on a ATTiny45 uC, so if you are planning on using any other uC I'd push you towards common Cathode LEDs.
Phew! Are you still with me?
Microcontroler (uC)
The uC is the brains behind the Pixel. We tell it what colour we want, and it controls the LED. For this project, I'm going to suggest you use the Atmel ATTiny45, because that's what I used, and it's fairly easy to get hold of. The CYZ_RGB project also supports the ATTiny 44 and 85, and other 4k+ uC's in the ATTiny range might work, It depends on how much time you want to put in modifying the code. I was lucky, I found the ATtiny45 on sale at Rapid Electronics (in the UK) for 90p each (about $1.50 US) so snapped up 10.
Resistors
The resistors are used to limit the current that passes through each 'die' of the RGB LED. When you buy the LED's you should get a datasheet that shows various details on the electrical characteristics of the LED, such as the forward voltage and current for each colour. You will need to put these into a LED resistor calculator along with the supply voltage (I would recommend 5v, but it depends on your application). The results will probably end up around the 100 Ohm region, with the value for the red LED being a bit higher. At this point I'd like everyone who knows anything at all about electronics to move onto the next section while I talk for a second about how I do things. Please don't shoot me for what i'm about to say.
LEDs and uC's are cheep. You are going to blowup/melt/fry a few of them. So buy extra. I've never been SuperMathsMan and I don't have a lot of patience when it comes to numbers, I tend to design circuits by trial and error. A current limiting resistor on an LED is there to stop the LED sucking so much current that it melts itself and/or the pin of the uC it's connected to. But it's a balancing act, if you use a resistor that is too high in value, your LED is going to be dimmer than it could be, because you are preventing enough current getting to it and If you use a resistor that is too low in value, your LED might be really bright, but it will burn it's self out and probably take the uC with it. Start of with what ever the LED calculator tells you to use, and then see if using a slightly less resistive resistor makes the LED brighter. leave the LED on for a while with the lower value resistor in, and touch the uC with the back of your hand or the top of a finger to see if it's getting hot, if it is, use a higher value resistor. If stuff melts or you let the smoke out, then smile and recognise that you've found the lower limits of the resistor you can use. It's all part of the fun.
Well done for making it this far, but unfortunately, it's not quite over, there are some tools you are going to need.
- Breadboard and breadboard wire
- Arduino - See note below.
- (Optional) Programmer for flashing hex files onto the uC (I use this one from Adafruit)
- Soldering Iron (a good one), Solder, tip cleaner, solder sucker, wick etc...
- Helping hands, or desk clamp thingy
- Good Lighting
You are going to need an Arduino for a couple of different things. It's main job will be to control the chain of pixels you are going to build (why stop building at one?) but it can now also be used to flash firmware onto the chips using ArduinoISP, replacing the need for a dedicated chip programmer. I don't use ArduinoISP, and it does sound like it's got a few issues it needs to work out before it's allowed to wear the awesome badge. I don't think it works yet with the Arduino Uno, and if you have an arduino that uses a Mega328 chip, you need to use a resistor to change the auto reset function. However it's a good option if you don't have a programmer.
Lets move on.. It's time to program some chips!
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I have been playing with this for the past 2 weeks... I have an attiny85 and im also using common anode but when I use the firmware that you have and also the one from CZY, it doesn't work. When I use the BlinkM flasher to burn... no problems and the works sequencer. I have no idea what im doing wrong. any insight?
just attiny85 using avr burn-o-mate with the fuse off for the 8 divide.
any information is helpful.
So I bought 20 of the ATTiny45, and some LED's. The LED's haven't come in yet, but the processors have. I thought I could start playing, using some LED's I had laying around.
Okay, so after a little back and forth on the programming of the chip, I was able to get the Arduino as ISP working. I soldered a 8 PIN DIP to an Arduino Proto Board, and wired it up. I was able to flash it, and I had success. I disabled the CKDIV8 in the fuses.
I hooked up the ATTiny45 to a breadboard, and then proceeded to wire it up. I loaded up the Arduino Sketch for the BlinkMCommunicator, and the Sequencer with no lights coming on. I crossed the Ground with each of the resistor legs to make sure I had power, and I did.
So I dug into the sketch, and I was getting "Looking for a BlinkM: No I2C devices found"
I loaded up the multi-track sequencer, and did a scan, and it didn't find any either.
So, does this sound like an addressing issue? Anyone ran into this? Have any other ideas for me to check out?
Thanks so much in advance.
http://www.youtube.com/watch?v=IIGq40xvRec
im using piranha common cathode LEDs, i can`t get it working :(
please help me
greets from germany.
You don't need to use the firmware that I modified, because that's for the other type of LED's
Jim
connect LED to PB 3/4/1 ? with resistors of course... cant get it workin :(
greets from germany!
Jim
AVR Studio 4 isn`t recognizing my USB tiny ISP.... what can i do ??? oO
if i flash the .hex via avrdude it gives me a "success" and a led lights up...
rgb led is connected to GND -- common cathode and the R, G,B with a resistor to PB 1/3/4
in BLinkM Sequencer, at scan I2C bus nothing is shown
help please!
greets from germany ^^
all working now :D Thanks a lot :D
but tell me, do i always have to connect ghettopixels--arduino--pc ??
greets
Jim
1. Open Edit > Edit Channel IDs and change at least one channel #s to 0 (easiest to just do the top one). This will make one of the sequences on the main screen address 0 and now should be tied to your chip/LED.
2. If you want to change it, highlight channel 0 (the one you just set), select Tools > Change BlinkM I2C Address, and enter the new address. The # along the left of the sequencer should change to.
3. If you go back to Edit Channel IDs, the LED should now glow the color of the channel ID in the list. If not...it's just a matter of continually trying to reset it. Some of them I had to close/open the sequencer, reconnect the Arduino, etc. but you'll eventually get it. The key though is to see if it glows the correct color when opening the Edit Channel ID menu.
Next I need to figure out how to run them from a single chip with pre-programmed sequences that I can control using like a push button switch to toggle through them! Any idea where I might find a tutorial on that? :)
If doing common Annode, I would think you just connect that to an external power source, then tie in the ground to the ground on the arduino. But for common Cathode, I'm not sure how you'd do that.
Post some pics of your builds!
Jim
If so, how would you hook it up?
I'm trying to build one of these but I try to use it with my own arduino Sketch. I connect the RGB pins to pin 1,3,4 on my ATTINY45. But on Pin 3 and 4 the led simply blinks instead of fading on or of. On pin 1 the LED fades in and out like it should. If I have read the specs for the ATTINY45 correctly, only pin 0 and 1 support PWM. Is this the reason? But how does it work with this blinkm firmware then? They don't use PWM to fade the RGB leds in and out?
My source for my arduino sketch:
int redPin = 1; // Red LED,
int greenPin = 3; // Green LED,
int bluePin = 4; // Blue LED,
// Program variables
int redVal = 255; // Variables to store the values to send to the pins
int greenVal = 1; // Initial values are Red full, Green and Blue off
int blueVal = 1;
int i = 0; // Loop counter
int wait = 15; // 50ms (.05 second) delay; shorten for faster fades
int DEBUG = 0; // DEBUG counter; if set to 1, will write values back via serial
void setup()
{
pinMode(redPin, OUTPUT); // sets the pins as output
pinMode(greenPin, OUTPUT);
pinMode(bluePin, OUTPUT);
}
// Main program
void loop()
{
i += 1; // Increment counter
if (i < 255) // First phase of fades
{
redVal -= 1; // Red down
greenVal += 1; // Green up
blueVal = 1; // Blue low
}
else if (i < 509) // Second phase of fades
{
redVal = 1; // Red low
greenVal -= 1; // Green down
blueVal += 1; // Blue up
}
else if (i < 763) // Third phase of fades
{
redVal += 1; // Red up
greenVal = 1; // Green lo2
blueVal -= 1; // Blue down
}
else // Re-set the counter, and start the fades again
{
i = 1;
}
// we do "255-redVal" instead of just "redVal" because the
// LEDs are hooked up to +5V instead of Gnd
analogWrite(redPin, 255 - redVal); // Write current values to LED pins
analogWrite(greenPin, 255 - greenVal);
analogWrite(bluePin, 255 - blueVal);
delay(wait); // Pause for 'wait' milliseconds before resuming the loop
}
So let me get this straight, you are using an arduino sketch compiled for the ATtiny45, probably using the core libs from the MIT group? That's very cool, I've been meaning to play with this for a while.
You are correct in both your points. Yes, the Attiny45 only has two PWM timers available, and yes the blinkM uses PWM to control all three colours.
The significant difference is that blinkM's and the CYZRGB code that we use here implement software PWM, rather than than using the hardware timers. (to be specific, I think they use the two hardware timers, and then the blue channel is done in software) . Read up on software PWM, that should give you some ideas.
Jim
I would just liek toknow if this could be applied in the same manner to a Luxeon III Star Led like this one:
http://www.seeedstudio.com/warehouse/index.php?main_page=product_info&products_id=194.
i am kind of new to the whole electronics/led world and i've kind of hit a wall here.
im trying to get together an RGB LED preferably a luxeon or cree with super high light output and control the color sequences.
please advise,
Much appreciated.
Jim
The junk you are seeing in the serial monitor is almost certainly due to the eron baud rate. try changing the baud and seeing if you can get any sense out if it.
As you are using common cathode LED's your best bet would be to head over to the CYZRGB project and download their binaries, don't use mine.
Jim
Thanks. If by "-ve line from the tiny85" you mean PIN4 (GND) tied to the LED cathode, it's not. They're both tied to a common ground, but not each other.
And yes that's what you meant, I'm not sure exactly what you mean in terms of specifics... if I wire PIN4 to LED cathode, they'll connect but there won't be anywhere for GND to flow to.
Or maybe you meant something else by '-ve'?
Jim
The Arduino IDE defaults to 9600 baud. The ThinkM script initializes serial to 19200 baud. Apparently the Arduino IDE can't detect this, self-adjust, or warn and so the text is garbled.. once I set the serial monitor to 19.2 I can read the output fine. Hopefully this helps someone else.
The LED still isn't doing anything, but at least I can start debugging it. Maybe I missed a setup step at the end. Feeling better at least :-)
Thanks
Serial console works perfect if I base a simple sketch around:
Serial.println("Hello World");
Let me ask this.. Are you using 0022 IDE?
I see in the BlinkMCommunicator sketch code, there have been past issues with it not working on a Arduino IDE release (there is a comment of 0012 incompatibility fixes in blinkM_funcs.h). It might be that again, or something else I just don't see.
The Arduino Uno has BlinkMCommunicator loaded. No errors uploading it. When I enable DEBUG in the sketch and open the serial console, each time I rese the Arduino it prints this junk: ¬ÖÖoÈg÷ãÃOþ
The ATtiny85 uses the type 85 firmware for CYZ_RGB. No errors when flashing it.
Arduino:
Analog IN A4 -> ATtiny85 PB0/PIN 5
Analog IN A5 -> ATtiny PB2/PIN 7
5V -> ATtiny Vcc/PIN8
GND ->ATtiny GND/PIN4
ATtiny85:
PB5/PIN1 -> empty
PB3/PIN 2 -> LED anode A
PB4/PIN3 -> LED anode B
GND/PIN4 -> Uno GND
PB0/PIN5 -> Uno A4
PB1/PIN6 -> LED anode C
PB2/PIN7 -> Uno A5
VCC/PIN8 -> Uno 5V
I saw in one comment that the schematic should be exactly the same if you use common anode or common cathode. So I did not change anything.
The LED is good.. if I move the 150ohm resistor to 5V, that color lights up.
At this point I can't tell if it's an issue with the controller on the Uno, my wiring, or an issue on the ATtiny.
i build 10 "BLinkm clones" aka Ghettopixels.
now i want to place them in my floor and i want to use cat5 cable to connect them... will this work ? i got about 15meters length...
Thanks for upcomming answers
My question is regarding a PCB boards. i see on this link (http://sjalbers.nl/Atmel/BlinkM/BlinkM.htm) that he has his mounted on PCB's. Ques: has he made these him self? if so how?? i really want to make some of these..
thanks
I just ordered most of the parts I needed for this... going to start by cloning 10.
For folks that appreciate this, there was another clone attempt of BlinkM someone did recently. It too is a nice effort (and includes a batch of custom PCBs): http://sjalbers.nl/Atmel/BlinkM/BlinkM.htm
Blinky stuff == AWESOME
I expect the 10PU is all that is needed (and if you notice, the author's bit.ly links actually link the 10PU model).
However, Mouser charges much less for the 20PU model ($1.87) vs the 10PU model ($2.30).
There may be other differences between the 10PU and the 20PU, however I can not qualify that (read the spec sheet).
Would be interesting to hear from some readers who made this..
Yes good point, I was using the 10PU version because they were on special offer at my supplier, The 20PU's would be just as good, and could even be a bit better. I too would love to hear from anyone who has got a comparison.
Jim
Jim
!st how do I stop the flicker? some colors are solid and others flicker alot
I am using your firmware for the common anode and I finally got everything working alright. I am using the sequencer and everything works except when In upload to the blinkm. It doesnt seem to be holding the program. It just turns a solid color. Have you had this issue?
thanks
bryan
The flicker could be due to the 'Clock Div by 8' fuse being set, which would mean the chip is running 8 times slower than it could be. Read up on fuses and perhaps download something like AVR Burn-O-Mat to set the fuses using a GUI.
Yes, the firmware will only hold about the first 5 bars of a sequence generated with the BlinkM sequencer, but not the full sequence. If you want to use it in a stand-alone context, you'd probably be better of buying a proper blinkM. The guys who wrote the CYZ_RGB firmware sacrificed some (most) of the storage area for better colour interpolation
Jim
Wonder if a large surface mount type resistors would make it a little more compact.