I recently purchased an Arduino Due from an $18USD credit from ITEAD. I immediately went searching for something unique to use it for, that’s when I found the ElectroSmash pedalSHEILD and thought that’s the perfect thing.
Above is a picture off Electrosmash’s website showing how it all fits together, below is my finished product.
It took me about two hours to complete the kit. The instructions were clear and precise and plenty of pictures if you needed to double check something.
Below is the ITEAD Arduino Due clone that was purchased separately. This is the only board that can be used with the pedalSHIELD Due, however there’s the option for the Arduino Uno called the pedalSHIELD Uno. (not pictured)
At this stage I’ve tried all the example sketches but haven’t had time yet to try my hand at making something uniquely my own sound.
On September 28th the STEMTera bread board was launched on Kickstarter. This is an Arduino compatible micro controller inside a modified solder less bread board. This caught my attention because I mainly tinker with Arduino stuff whilst sitting on the couch! So there are times when I’d have multiple pieces of gear with a rat’s nest of wires (that’s pretty much the norm for this kind of thing!) However the STEMTera bread board essentially removes the need to have your micro controller then a bread board for components , in that you can place items directly on the STEMTera thus saving some space (if that’s a concern) so I pledged for the $45 backing with delivery for mid to late December. Oh and I got mine in black as that to me seemed logical for the least amount of light bleeding through the plastic cover.
Skip forward a few weeks and I’m now using the STEMTera board as my go to board for anything Atmel 328p based. I’m kind of hoping that a SAMD (M0) or STM32 (M3) will become a reality in the not to distant future.
With Xmas not far away I’d ordered some LED tea Lights for the wife to make some decorations to give away to the family. I was interested to find out what was driving the LED, but because all the candles were required I was not able to autopsy one to find out. This got me thinking, I have an Adafruit Trinket that would be great to drive an LED via PWM and create the desired flame effect.
Now after searching the web for examples of what it was I wanted to do, I finally settled on this one from .ledhacker This is pretty much what I was after! Here’s a copy of that original code…
So I loaded this on the Trinket and at first I didn’t include a current limiting resistor and the LED showed a slight flicker, but not anything like a flickering tea light! After adding the current limiting resistor (220Ω)and that didn’t really change much except for dim the LED ever so slightly. So obviously I needed to tweak the code and see what I end up with..
Now my first thoughts on why it didn’t work out as expected is that the code was obviously written for a 5v logic, however this trinket is 3.3v logic. I made the following changes (after a little fiddling)and got more of what I was after 🙂
< #define FLICKER_LED_PIN 10
> #define FLICKER_LED_PIN 0
< static int flicker_low_min = 200;
< static int flicker_low_max = 240;
> static int flicker_low_min = 15;
> static int flicker_low_max = 175;
< static int flicker_high_min = 230;
> static int flicker_high_min = 180;
< static int flicker_hold_min = 40; // milliseconds
> static int flicker_hold_min = 20; // milliseconds
< static int flicker_speed_min = 900; // microseconds
> static int flicker_speed_min = 800; // microseconds
As you can see I only made small changes to some timings and they seemed to work better for the 3.3v logic
The next thing was how long would this run on a 1000mah lipo battery? well, somewhere between 4 to 5 days!
I’ve placed the code and supplement files on github should you wish to make one. 🙂