Flight Suit V3

The next version of the LED Flight Suit marches forward with WM, lots of headway on key components:

• Three 16-channel, 12-bit pwm PCA9685 chips will operate MOSFET's to switch 48 LED strips.
• Small sot23 smd MOSFETs (or these); the old ones (P16NF06's) were too overkill, too big. Overkill is still good but there's some math this time.
• RC batteries for more power: peak 14.8V and 12A no problem, but will be <500mA most of the time.
• Thinner, lighter LED strips with 120 LED's/m.
• Arm-based remote control with a 1.3" OLED screen, dials/buttons/sliders/TBD.
• The remote control will hopefully be a second Arduino-based system, a serial peripheral to the main suit system.
• Multi-band audio analysis with MSGEQ7 or a separate Arduino FFT.

Most importantly WM is coding Arduino!  He already built a complete mode-switching, parameter-adjusting system with a figure diagram on-screen!  

We'll make the suits themselves-- the displays with LED strips-- when we have a working circuit and software: we don't know where everything's going yet.  So for a demo display I'm making a circuit board showing all 48 PCA9685 outputs on LED bars-- old school.  Here's the one I'm scrapping-- got too much rework:

and here's an MSGEQ7's output, from iphone audio, of seven values on a Sure Electronics 24x16 panel:

That display will also help when debugging and building the system.

Handmade/Homemade Board: "My Arduino III"

I love homemade boards, and this layout is by Carlos Rodrigues is lovely!  From Flickr:

Construir o meu próprio Arduino, fase 3: alguns upgrades.

Tem agora melhor protecção contra ruídos na alimentação, reset automático ao iniciar um upload, protecção contra excesso de corrente no USB, e o bootloader do Arduino Uno.

Translated by Google:

Build my own Arduino, phase 3: a few upgrades.

You now have better protection against noise on power, automatic reset to start an upload, protection against excess current in USB bootloader and Arduino Uno.

[diagrams]

New Arduino Micro

Adafruit did a lovely job with the Arduino team on the new official Arduino Micro. Everything is tiny, with a smaller ATmega32u4 and parts on the top and bottom, some the smallest components available-- seriously micro! It's available now for $25.

Pantry Light Demo

The pantry light is installed and working perfectly: I'll post code and circuit details eventually, not much to it though.

Next Projects: More and Less Power

Arduino is part of my life and has been for years now: I constantly use the homemade, Arduino-based appliances in my home the same way I use appliances other people made. But while I'm hooked on building out my world the way I like it, sometimes a project only needs a handful of pins, so I just ordered a few ATtiny85 and 2313's to try my hand at [gulp] proper AVR programming. It's too bad that Arduino is going toward the high end with the Due instead of toward the low end with smaller, simpler circuits and chips, but I'm happy to go elsewhere to learn. I could hot-wire the Arduino environment to program an ATtiny, but I'd like to try transitioning to a more fully-featured IDE for future development anyway, so programming an ATtiny will be a good sub-project.

Speaking of "the high end," the $25?! (OK really $50 but still!) Raspberry Pi has been on my radar, maybe for something using some cameras and image analysis-- things an Arduino would struggle with. I'm especially excited lately after hacking around with a $25 WiFi access point and OpenWrt... wow! Amazing how much power can be had for so cheap, and how many how-to's can help you along.

What do you think? Have you left the "safe" space that Arduino provides, and moved to different processors and IDE's? please leave a comment.

MaKey MaKey: I Want One!

Jay Silver's "MaKey MaKey: An Invention Kit for Everyone" raised over a half million Kickstarter dollars (above a $25K goal) and he deserve the crazy success-- the video is a brilliant demo/sales piece that on its own inspires you to make things... and of course buy a Makey Makey. Just awesome stuff, and at its core: an Arduino! I'm adding it to the spreadsheet... after ordering one or two...:)

1-Day Project: Pantry Light

We have two pantries in our flat, one of which could use some light.

There's an outlet in there, but a simple solution won't do: I have more circuitry and time on my hands than I can handle, and the least I can do is make an over-complicated pantry light.

Parts lying around to use:

• AC-DC converter blocks with screw-terminals outputting 12V at 2A. I have a bunch of these-- came with the LED strips.
• A length of white LED strip.
• Lots of TIP-120-style MOSFETs, intended for a second light suit. It's fun to have a lot of high power switches around.
• Spare Arduino-compatible board "StripDuino" by "Tinkeract.com," now defunct it seems. Thanks for sending the free board!

The idea is simple-- rest your hand on the large strip on the door sill as you scan the pantry contents. The light will turn on if you tap the strip, or it will fade if you leave your hand on it.

This design solves the problem uniquely with:

1. Very large switch surface,
2. Variable brightness by holding the switch,
3. Indirect lighting from compact, dense LED strip tucked out of view.

I have a hardware sketch working in terms of the key elements of the controlling Arduino system:

• Capacitive touch sensing works between pins D5 and D6 with a 1M resistor
• Touch surface works: aluminum foil with soldered wire plus a layer of hot glue and tape.
• PWM works with the MOSFET to control the LED strip nicely, with the board's 3.3V logic.

For the light strip at full power, I measure 240.8 mA at 11.85 V, so 2.85 W of power. This is not much but it scales proportionally to the length of the strip.

To do:

1. Capture the working circuit in an Eagle schematic.
2. Build a looping sketch with the tap/hold fading behavior.

More to come...

Arduino Leonardo Video Introduction

IEEE Spectrum: The Making of Arduino

An excellent article in IEEE Spectrum magazine gives a rundown of the origin of the Arduino board, outlining the motivations behind the open source design and the increasing impact it has on creative communities all over the world. It's a good read for answering the question, "What is Arduino?"

What is "Minimalduino"?

I started working on the "minimalduino" design as...

1. a minimal hardware design for an Arduino-compatible board. At heart, it is very similar to the Dorkboard, but
2. designed to match the form factor of the "official" Arduino boards so users can benefit from the many, many shield boards designed to fit on top. While (awesome) boards like EMSL's Diavolino are also low-cost and shield-friendly, I wanted to explore
3. optional hardware configurations, with different power connector options (pin headers, JST connector, barrel jack, screw terminals, or mini USB jack), 5V and 3.3V power regulation and optional voltage switching and regulator bypassing, and options for crystal and caps or a resonator. I also wanted to have
4. better shield-friendliness by placing LEDs (power and D13) and the reset switch (side switch or top switch) at the edges of the board, and lastly, I wanted the board to be
5. single-sided, home-etchable with wide traces and minimal jumper wires. There is still work to be done to reduce jumpers, but it improves on the the S3V3 "Severino" board which doesn't match up size-wise (it's bigger), the standoff mounts don't match, and it uses a DB9 serial connector instead of the now widespread FTDI USB-serial breakout cable.

3-Digit 7-Segment Display With an SAA1064

Working on the grinder timer project, I built out a basic circuit (EAGLE .sch) with an NXP SAA1064 and resurrected a test sketch (Arduino .pde) for it. The SAA1064 works beautifully for driving common anode 4-digit 7-segment displays with constant current per segment, from 3 to 21 mA in 3mA increments; in this case I'm only driving three digits since that's what the design calls for.

There are two buttons in the test sketch (on D10 and D11), the first to change count modes (seconds, tenths, hundredths, hex, and "chase") and the second to cycle through the seven current settings.

This schematic is identical to one I did a board layout for with an SO24 package chip, but for some reason those boards didn't work; maybe something in manufacture or assembly bridged pins somewhere. I'll redo the layout and see what happens, with vias further from pads.

Minimalduino 105: Nice!

I built out one of the "V.105" boards I got a few weeks ago from the DorkbotPDX PCB order, and it works beautifully, almost identical to the version 107 I posted files of, with "5V/3.3V" voltage and "FTDI/IN" power selector switches. I mounted a mini USB socket and a 7805 regulator, in addition to the barrel jack for power in.

I've gone to whole number versioning btw, no need for "always under 1" versioning or major/minor versions, and if I need to go higher than 999 (huh?!), I can just use four digits.

Top and bottom labeling came out great, including the Open Hardware logo, though the letters mush together a little. Also, the "FTDI" header label didn't print at all, maybe there's a problem having two "FTDI" text labels.

One issue is that the drills for the main female headers are smaller than those on versions 89 and 97 boards, even though they use the same parts in EAGLE! I'll check the parts and maybe swap them out. That's a bummer-- I had to drill them all out to mount the headers, which ripped some of the pads off the fiberglass, but thankfully they stayed connected to the traces.

Minor edits for the next version:

• Move the power input components to give electrolytic capacitors more room to accomodate shorter/fatter ones or taller ones mounted horizontally. As it is, the 100uF cap at the input is jammed between the .1uF cap and the barrel jack. [done]
• Rotate LED's so they can be mounted horizontally for better side viewing when using a shield. [done]
• Add heat sink polygon and vias under the 7805 tab.
• Fix the Sparkfun mini USB through-hole part: its outline is on the bPlace layer, not tPlace where it belongs. Or just use a different part. [done]
• Check female header drill diameters.
• Add 2-pin header at the reset button to make it easier to add a remote panel-mounted reset button. [done]
• Round the corners; looks nice on the Freetronics boards. Also check Uno outline and drills to make sure things are lined up right. [done]

I'm pretty happy with this for now though-- I have plenty of cheap, homemade, 5/3.3V-switchable Arduino-compatible boards to work with!

Canon IR Remote Control

After striking out at the Electronics Flea Market Saturday, I stopped at Fry's for a fresh pair of clippers and soldering tips, and picked up a small case too-- a Serpac M4. I used some free protoboard Laen sent me (THANKS!) to build a simple Arduino-compatible circuit to fit inside it, with a single button and IR LED, powered by three LR44 (AG13, 357, etc.) button cell batteries; basically a mutetater circuit with one LED instead of four.

Following Martin Koch's code example, I got the circuit to trigger my 350D's shutter, making it functionally equivalent to a Canon RC-5 remote control. Using an ATmega168 is overkill though: most pins go unused, and it nearly drained the three LR44 batteries when left on all night.

I figured putting it to sleep would solve the power consumption problem, so I modified the ArduinoSleepCode example from the Arduino Playground to make the D2 button both wake it up from sleep and trigger the shutter. It doesn't need to be awake for any time at all really before going into "SLEEP_MODE_PWR_DOWN": the wake up function triggers a shutter release event; currently it sleeps after five seconds. This will be a key feature of the mutetater and a more complete intervalometer-- using a button or a DS1337 clock alarm to wake up when needed.

Files:

• Arduino sketch (zipped),
• EAGLE CAD schematic file,
• EAGLE CAD board file

Minimalduino v.89 Delivered

Three copies of my latest Minimalduino design (V .89) arrived today, fabricated in the DorkbotPDX circuit board order. I built one with all components and it works perfectly, with the exception of the 3.3V regulator having a different pinout than the 75LXX part I used in Eagle-- oops...

A SparkFun protoshield and Adafruit motor shield fit on top fine, but with very little (read: "zero") clearance over the tall capacitors I used-- they'll get some tape on top, and the next revision will use shorter caps or orient them sideways. Excited to work with my first factory-made board, I shot and posted some build pictures with a few notes.

To correct in the next revision:

• Fix 3.3V regulator (MCP1700-330) pinout,
• Lay out for wider/shorter or horizontal voltage regulator caps for better shield vertical clearance.

To add/improve in the next revision:

• 5V/3.3V switchable with a jumper on three pins (though it will limit power),
• Top pad and through holes under 7805 for better heat dissipation,
• Credits (CC, author names) on bottom silk screen,
• Optional resettable fuse?
• Optional on/off switch or jumper pins?
• Try to reduce the number and length of jumpers.

New(ish) "Official" Arduinos

The Arduino FIO, announced at the New York Uno Punto Zero meeting, is Shigeru Kobayashi's Funnel I/O board, now officially in the Arduino stable, manufactured and sold by SparkFun Electronics ($25). It runs at 3.3V, at 8MHz, and includes voltage regulation, a LiPo charging chip, and an XBee socket. Note that the USB connector is only for power, not for programming.

The Arduino Nano 3.0 by Gravitech ($35) got a lot of press in the last week after being stocked in the Make: Magazine Maker Shed (though it was actually rolled out in July). This revision has LEDs for power, RX, TX, and D13; auto power sensing; power regulation and USB programming interface-- pretty much everything a full-sized Arduino has, plus the two extra analog input pins available on the smd ATmega328.

Both are listed on my comprehensive Arduino-compatible boards spreadsheet. I find it interesting that neither of these conforms to the original Arduino form factor, which makes sense given how little space smd components occupy and how often auxiliary circuits are built on solderless breadboards. Still, breadboard tinkerers miss out on the awesome functionality built into shields, which was the motivation behind the Minimalduino board.

Minimalduino: Three, Please!

I got the latest version (.89) of my Minimalduino board to Laen at DorkbotPDX before the deadline this morning-- looking forward to getting three copies of it!

I met all of the specs I laid out in my original post, except there are no TX/RX LEDs and no SPI header. Keeping it exactly the same size as the Diecimila/Duemilanove meant more (and longer) jumpers than I wanted, but I like the layout over all, and the jumpers won't matter for the DorkbotPDX order since those will be 2-sided boards.

My favorite features are the button type options (top or side), power connection options (barrel or screw terminals, plus .1" separated pins), I2C header, and extra standoff mount-- the three Diecimila/Duemilanove standoff mounts never seemed adequate to me.

Motoruino

Guilherme Martins announced his fantastic "Motoruino" (flickr set) freeduino board on March 9. It has a shield-compatible pin layout, power pins for each Arduino pin, and a L293D motor driver circuit on the right side. I like that he didn't bind the driver to any particular Arduino pins and included three ways to attach motors' leads. I can't wait to get my hands on one.

PPAC Fixes, Minimalduino, Timer

I've been busy lately and haven't had as much time as I'd like to tinker, but I've gotten things moving in the last two weeks and am overdue to post.

Hoping to show off the alarm clock a little, I brought the PPAC (including power block, valve tree, and tank) to the Make:SF Meetup last month, and while talking and hooking it up at the same time, plugged the AC supply into the DC power socket! The voltage regulator fizzled but the power board seems fine otherwise. Strangely, of all things, the LCD display was dead as well... though I may have killed it when disassembling the can..:o I ordered a better looking LCD replacement which I'll install in the next few days-- green-on-black instead of black-on-green: Newhaven NHD-0216K1Z-NSPG-FBW-L.

The minimalduino project is still moving forward: I'm using a test board I made at home a few weeks ago, populated with as little as possible: chip, caps, resonator, female headers, reset and male FTDI header. I'll move a few traces around but it's pretty much there, and hope to get three test boards made through the DorkbotPDX PCB order, deadline noon on March 29. I've built a spreadsheet with costs, and it seems like I could make a batch of 25 kits at just under $15 each. I'm not sure if it's worth the trouble though.

A few weeks ago, I built a new coffee grinder timer with a re-worked sketch and single board, then handed it off to fellow coffee fiend HF for ideas on how to make the ideal grinder timer. One thing we agreed on is that tenths of a second would be cool, so last night I had a great time working out a sketch to drive a common anode 3-digit 7-segment display using an SAA1064 IC. Of course having a sketch to start with made things straightforward-- thanks Alessandro Saporetti! I reworked the code to make it more general purpose, using all of the chip's functions including multiplexed (versus not) and changing the constant current output (7 output levels possible, from 3 to 21mA). [Video to come]

100K Views!

The PPAC "Inflation" YouTube video had its 100,000th view today-- wow! Thanks, viewers!! The big spike happened on December 14 when it started showing up on my favorite blogs, and it has been getting >1000 views a day since then.

• Make: Online: "Inflation alarm clock pretty much rules out snoozing "
• Gizmodo: "'Princess and the Pea' Alarm Clock Makes It Impossible to Stay in Bed"
• Hackaday: "Clocks that only a geek could love"
• Neatorama: "Inflating Alarm Clock Pushes You Out Of Bed When It's Time To Get Up"
• The Daily What: "Alarm Clock of the Day"

Here it is again:

Also, the first "ejection" video:

Mute-tater lives!

I've been working on the mutetater program and board, and have it mostly sorted out, including the bulk of the mounting details. I etched a small 1-sided board to hold my old Arduino Mini, with transistors rigged like the TV-B-Gone v1.2, and headers for four LEDs, a button, ftdi programming cable, and 5V power. I'm using a Bodhilabs "VPack" with a single cr2032 to get 5V, and its header works nicely for mounting a power switch. It all fits in the foam potato, so now to figure out the button and LED mounting.