User clinton blackmore - Chiphacker

What should I know when making a library for the Arduino?

2010-06-05T03:13:13Z

It occurs to me that, beyond my current problem, I ought to ask, "What should I know when making a library for the Arduino?"

First, what I am doing:

I'm using Eclipse as my editor and writing code in C++. I have written a simple Arduino application that includes my header file and am working through errors.

First problem: how do I do a 'build clean'? I am seeing errors that I think I've fixed, almost as if the header file were cached. (Yes, quite likely I am doing something stupid [edit: I was], but I'd still like to know how to clean the library, and don't know where the object files are).

Secondly: what conventions should I be aware of? I haven't used the Arduino as much as I'd like, and it feels so good to be programming in C++, but I know the intent of the libraries is to keep things nice and simple for the users. Are there conventions for function names? Creating constants (it looks like the global namespace is polluted with #defines)? And so on.

Lastly, is there anything else I should know?

I should mention that I've looked at the Arduino Library Tutorial, which is good, but doesn't go very far. I've also peeked at some of the libraries that are installed on my system.

Continuous rotation 'servo' vs DC motor

2010-03-25T14:50:01Z

Under what circumstances should I prefer a continuous rotation 'servo' to a DC motor, or vice versa?

It seems to me that to use a DC motor, I'm going to need three pins from an MCU -- two for forward/backward/brake/coast and one for PWM. On top of that, I'll need an H-Bridge.

For a continuous rotation servo, I'll only need one signal pin and some code to send proper timing signals. I can't control the speed of the servo, can I? Also, it must have something akin to an h-bridge inside the motor, which surely ups the cost, but the motor will always be geared, which is a plus.

So, what are the pros and cons of each, and when should I choose one over the other?

Answer by Clinton Blackmore for so i have a lego mindstorms 8547 and 10 kids for an hour a week, what should I do?

2010-04-21T16:53:58Z

Here are a couple of things to get you started. ~~(BTW, how old are your students?)~~

work through projects on http://www.nxtprograms.com/ . These start with simple and fun things you can build, and have documented programs you can download.
take a look at http://www.thenxtclassroom.com/ and sign up for the robotics in education mailing list.
take a look at http://www.legoengineering.com/
There are many other good sites out there (that I can't think of offhand). I really enjoy following The NXT Step blog.
There are a lot of good NXT books out there. I haven't had a chance to look at many of the new ones focusing on the Mindstorms NXT 2.0 kit. [Be aware that there are currently three different NXT sets with different pieces in them (ie. they are not backwards compatible, you can't build NXT 1.0 models with an NXT 2.0 kit without making adjustments).]
I highly recommend teaching the kids Scratch. It is free, they can use it at home, and it helps them understand how programming works.
you might also find some of my ideas in the answer to "Any good suggestions for a beginning electronics class for youth?" to be interesting.

Am I correct in thinking that you have a single Mindstorms kit?

H-Bridges and Motor Stall Current

2010-04-05T15:29:36Z

How do I determine how powerful an H-Bridge I need to control a DC-motor?

In particular, does an H-Bridge need to be able to supply the full amount of current a motor will use when stalled, or would it be okay to use an H-Bridge that supplies enough power for a motor under standard load (and then some, but not stall conditions), and if so, what happens if the motor wants to draw more power than is available? (Does the H-Bridge fry, or does the motor just stop?)

Answer by Clinton Blackmore for USB Host device

2010-04-09T14:45:37Z

I've never used one, but I'd look into the AT90USB1287 chip. It even comes in an handy evaluation board called the AT90USBKey. While the chip itself is supposed to be able to act as a USB-OTG Host, it isn't clear to me that the demo board supports that.

Hacking a singing, dancing plush toy

2010-04-02T15:00:43Z

My mother-in-law has sent my sons several singing, dancing plush toys (not unlike this or this), which are well enjoyed until the batteries go. Every time we get one, I can't help but think, "I must be able to hack this, to reprogram it or change the music." I don't imagine that I will any time soon, but I was wondering if anyone knows of a tutorial or blog post where someone goes through hacking one of these, or even a tear down. [Granted, they likely use several different chips, and they might not be rewritable, or may require hardware I don't have, but I can't imagine that someone hasn't done it and documented it!]

Yes, I haven't looked deeply into it. I suppose I'm wondering if it is likely to be something simple to do -- say, in a couple of hours or on a weekend -- or likely to be something to difficult to be worth the bother.

Answer by Clinton Blackmore for Any good suggestions for a beginning electronics class for youth?

2010-03-27T14:44:38Z

I had thought to ask a question like this, too.

My current thoughts are implied in two questions here:

Two asides that I have to mention, having met a group called LUMACS at my local university last night, which does outreach activities and week-long camps for kids:

they said it is easier to teach counting in binary and algorithms to young children than to adults
they recently got some PicoCrickets and the groups that used them did not want to move on to anything else [and I got the impression that the same did not hold true for Mindstorms robots]

For the youngest groups I would want to work with (maybe as young as 9, 11 might be better), I'd think I would:

Teach them procedural thinking -- ie. Scratch, on the computer.
Use a Arduino platform that is designed for plug and play [ie. the Seeed Studio Electronics Brick shield]
Use a forthcoming Scratch-like programming environment for the Arduino

For an older group (perhaps 14 and up), I think I'd:

still start with Scratch, and/or possibly teach them Alice
use a breadboard-friendly Arduino -- a Bare Bones Board kit or a Boarduino or an Ardweeny.
Get an experimenters kit of parts. (See bottom of this page)
Or go for a bundle -- this ARDX experimenters kit with an arduino and breadboard overlays sounds great!

Edit: I just tried out Processing, on which the Arduino programming environment is based. You may well be able to teach them Processing and then move on to the real Arduino environment.

This age might just be ready for a real text-based language, such as Processing and NodeBox. Processing, in particular, would be a good intro for the regular Arduino environment.

Now, on to robotics. I have taught three extra-curricular robotics courses, and most of my students have been homeschoolers. They range the gamat from kids who can hardly read (an major liability to learning) to incredible kids that I want mine to be like. I was amazed at how beneficial it was to have parents attend with their children in the last class I ran; I would highly recommend it.

The biggest advantage to working with homeschool students (at least where I live) is they have some say in how their educational dollars are distributed; I was able to offer a LEGO Mindstorms NXT-based course, and, with a teacher to sign off on it, they were able to put their educational money towards it to fund it.

Having taught three beginner NXT courses, allow me to say:

the NXT platform is great
the NXT-G programming environment is ... unsuitable ... for anything beyond beginner work. When it is not downright buggy, it is very tedious.
step back and have students work through things at nxtprograms.com. They are simple, whimsical, and well-built. [I'd tended to think, "okay, lets make a line following robot" and "now a sumo bot"; now I am thinking, "lets build something simple, fun, and creative"]
teaching Scratch beforehand is really helpful.

Only one of the twenty-one students I've taught was a girl. If I were to try to include more girls, I'd strongly consider using PicoCrickets (due to their crafty nature) and LilyPad Arduinos (same reason). I'd also read "New Pathways Into Robotics" [pdf], a paper from the Lifelong Kindergarten Group at MIT (the same people who make Scratch). It indicates taking a exhibition-related approach, where you choose a theme (say, "A Day In The Park") and have pupils build robots to display related to the theme (like a robotic caterpillar, or flowers that turn to face you).

With an older group, I'd consider BEAM robotics. It is robotics where you repurpose scavenged parts to build things, and typically use solar panels to power things. The best book on the topic I'm aware of is Junkbots, Bugbots, and Bots On Wheels.

Three other points:

I'd want to go with hardware that is cheap and modular. I'd rather, say, buy a special FTDI cable that has a USB-to-serial converter on it, and use a Freeduino that expects that signal, than use a regular A-to-B USB cable with an Arduino that has the converter chip. The cables are a one-time-cost. You save on every board. If you let the magic smoke out (and I expect you will and shouldn't fear it), then you buy another board. I'd also consider going for motor controllers on a separate board, so if the fry, only one part has to be replaced.
As for books, my recommendations will re-iterate what others have said:
- Getting Started With Arduino
- Make: Electronics
- Anything by Forrest Mims (ie. Getting Started In Electronics, from the 70s or 80s)
- Junkbots, Bugbots, and Bots on Wheels
It is not hard to host a robotics event. I've run two in conjunction with a science fair. Line following, an obstacle course, and mini sumo have proven to be fun. I've also hosted a robofest event, and working with Lawrence Technological University was great -- they provide almost everything and you provide space and volunteers. [You need to be in contact with them by October to get on the poster for events held in March/April].

Do let us know if you have any luck with such a course. I'll try to remember to edit this post if I do myself.

Is there a Scratch-like Arduino IDE?

2010-03-24T17:00:38Z

I believe that the answer is no, but I wanted to check before I put effort into rectifying it (and no, no promises!)

Is there anything like Scratch that one can use to program an Arduino?

(Scratch is a graphical coding environment that makes learning to program fun, and is certainly suitable for elementary students. It is put out by the Lifelong Kindergarten Group at MIT).

Newbie-friendly electronics (and robotics)

2010-03-24T18:05:35Z

I'm looking into alternatives to LEGO Mindstorms for the robotics classes I teach (in an effort to find something less expensive and thus more readily accessible.) I am working with children aged 11 and up.

I found a couple of interesting things lately, that one might call "plug and play" electronics.

Seeed Studio puts out Electronic Bricks. These look cool -- the components go together with cables (which I hope can not be attached incorrectly [without additional effort]) -- and the parts are reasonably inexpensive ($3-$15, instead of $35 to $65 for additional mindstorms sensors.] The cables can then be plugged into a protoshield on an arduino, and voila!, you've got sensors.
Inex puts out some items that look a little bit similar, but not as extensive.

I should admit that I've got nothing against LEGO. My main two ideas for getting the body of a robot include:

using an arduino 2WD or 4WD driving base. (The downside to this is that you can't rebuild your robot in imaginative ways).
using LEGO, with, say, a servo-to-LEGO adapter (or possibly by using existing LEGO motors and interfacing them to an arduino/MCU).

What other hardware-related electronics/robotics things should I be considering?

How do I physically work with a hobby motor?

2010-02-03T17:00:45Z

How do I incorporate a hobby-style motor into a project, physically. How do I mount it and connect a wheel to it? (Assume that I have a working H-bridge or even switches, and am not concerned about how to use the motor electrically, just physically.)

I've purchased small, hobby style motors at various times. Typically, they run on 1.5 V to 12 V, and many of them have no built-in gearing (and thus spin really fast with very low torque). How do I connect a wheel to it, or a gear or pully?

Next, most motors of this sort are round. Round! If it was flat on one side, I could glue it down. It looks like they are designed to be screwed into something at the front or back, but I don't know how I'd make a surface to mate to it nor make marks to drill holes through it precisely enough.

What have you found works for when you want to make an electronics project move around on its own?

Batteries for 12- to 24-V motors

2010-02-15T16:44:45Z

I have some nice gear motors that run on 12 to 24 volts, and want to use them in a medium-sized mobile robot -- maybe 30 cm * 30 cm for the base. I only expect it to run indoors, or possibly outside in nice weather. If it had a half-hour run time, that'd be fine. [If this is successful, though, I'd like to make a bigger robot that can withstand the out-of-doors, but probably only in nice weather].

I'm wondering what sort of batteries to use to power the motors. These are the choices I can see in order from what I think is best to worst.

Use one or two 12 V (lead-acid) batteries. This is sort of what I'm leaning towards, but I'm worried about how bulky and heavy it would be. A car battery would be far too large and heavy.

I already have a charger that claims to be "ideal for car, SUV, light truck, farm equipment, boat, deep-cycle, RV, motorcycle, ATV, snowmobile and lawn tractor batteries." I imagine it would charge any 12-V lead-acid battery.
Use some 9-V rechargeable batteries. They appear to typically be a little less than 9V, but it appears that there are 9V and 9.6V varieties. I would have to get a charger. These would be light, compact, but they won't last long. (230 mAH seems paltry compared to a ~~5 AH~~ 50 AH car battery.)

I would need to have two in series, and, I suspect, have two or even three series in parallel. That adds up to quite a few batteries and starts to negate the benefit of the small, compact batteries.
I could use 2 to 4 6-V batteries. (I didn't realize you could get rechargeable 6V batteries).
AA batteries, and lots of them. 10 to 20 1.2V NiMH batteries, though, will take a fair bit of space and mass and be take a long time to charge.
Specialty batteries (like those used in RC vehicles).
Some combination of the above -- say, two 9V batteries and a 6V battery.
Any sort of battery and a DC-to-DC adapter.

The first two options seem like my best choices. What would you recommend?

Answer by Clinton Blackmore for Electronics kits, any requests?

2009-12-27T16:13:04Z

I'd like a kit where:

the input is an audio source (such as a simple microphone)
the output is several LEDs (say, 8), each of which light up when a different frequency range is present in the input signal
- for example, LED 1 might light up when a frequency in the 40-80 Hz range is present
- LED 2 might light up when a frequency in the 80-160 Hz range is present
- LED 8 might light up when a frequency ending at 16 kHZ is present
- I really don't have a good feel for what ranges would be suitable, and it likely depends upon how the kit takes a time-domain signal and gives several frequency domain signals
the 'brains' of the kit could, I believe, be implemented using LC circuits or a DSP running a Fast-Fourier Transform.

The device should certainly have a threshold mode -- lights turn on when the threshold is exceeded. (Or, the output could be read [in parallel] by a microcontroller!)

It would also be neat if it had an intensity mode, where the LEDs grow brighter or dimmer depending on how much of the corresponding frequency range is in present.

Answer by Clinton Blackmore for Firsthand experience with Linux AVR IDE

2009-12-27T15:48:25Z

I haven't got any first-hand experience with it, but KontrollerLab sounds interesting.

Answer by Clinton Blackmore for Electronics kits, any requests?

2009-12-23T14:34:06Z

Well, with sound as your primary focus:

I'd like to see a device I can send encoded digital audio (PCM, perhaps) to (over I2C), and have the sound either come out of a speaker or a headphone jack (or line out).

Basically, it is a drop in sound module; all your microcontroller has to do is send it waveform data. (If I could send it musical notes and phonemes to play, that'd be even cooler!)

Answer by Clinton Blackmore for What's the difference between a microcontroller and a microprocessor?

2009-12-18T01:01:44Z

Microcontrollers:

are typically 8-bit, but may be 4-, 16-, or 32-bit
run at speeds less than 60 MHz
use very little power
may provide enough current to operate an LED
are useful to interface with sensors and motors
are readily replaced, being inexpensive ($0.10 to $10)
are really constrained for RAM and persistent storage (flash space)
are really nice for electronics hobbyists

Microprocessors:

are at least 16-bit, and typically 32-bit or 64-bit
many will be able to do floating point math in hardware
run at speeds measured in hundreds of MHz
are designed to be the brains of a system (and need a whole system to support them)
need special hardware to interface with sensors, motors, LEDs, etc.
are expensive (think $50 - $250)
are designed for external RAM and persistent storage (hard drives)
are not as easily worked with by a hobbyist

I find it interesting that the LEGO Mindstorms NXT set has a microprocessor [32-bit AT91SAM7S256 (ARM7TDMI) main microprocessor @ 48 MHz (256 KB flash memory, 64 KB RAM)] for doing the thinking, and a microcontroller [8-bit ATmega48 microcontroller @ 4 MHz (4 KB flash memory, 512 Bytes RAM)] for interfacing with the sensors and motors. [See technical specifications on Wikipedia.

Answer by Clinton Blackmore for Robot picking a person from other objects

2009-12-02T20:30:04Z

A smart sensor might help -- take a look at the CMUcam.

Answer by Clinton Blackmore for Good motor supplier?

2009-12-02T20:26:01Z

Solarbotics has a nice selection of Motors and accessories. They appear to ship internationally (from Canada).

Answer by Clinton Blackmore for Good tool for Mac OS X to draw circuits.

2009-11-20T16:58:35Z

Someone asked Make a similar question (that was not Mac-specific). Their answer suggests Fritzing, too, and there are other tools mentioned in the post and in the comments.

Answer by Clinton Blackmore for Cheapest, simplest way to implement a Bluetooth keyboard/mouse?

2009-11-17T21:28:54Z

It is not likely the solution you are looking for, but I thought it was relevant to the question:

http://serverfault.com/questions/43615/setup-a-linux-computer-to-act-as-a-bluetooth-keyboard-mouse

Answer by Clinton Blackmore for Apple Desktop Bus (ADB) to USB Adapter

2009-11-13T05:06:03Z

Are you expecting it to act as a normal keyboard, or just as something that works with special software?

If you are using an Arduino (say) with an FTDI cable, it will act like a device talking over a serial port. You can send interpreted keypresses, and any application listening will see them. (You would probably be best off to use 'screen'). However, an application will not be listening to the serial port for keyboard input under normal conditions, and you may find yourself disappointed.

If you want it to pretend to be a USB keyboard, you'll need a chip in there that has a USB registration code as a keyboard device. (I don't remember the proper term; probably some sort of HID -- Human Interface Device -- thing.) In which case, the question, "I’d like to learn how to make my own USB gadgets" has some relevance to you.

If you are using a standard AVR chip, you can use the V-USB firmware to make it talk like a USB device. See their examples of human input devices.

Alternatively, you could use an AT90USBKey and check out their USB Keyboard Demonstration [pdf]. Bumble-B sounds somewhat similar.

Measuring force developed by a robot

2009-11-10T20:58:01Z

I've been playing around with a Lego Mindstorms NXT robot, gearing it for speed and power. To my dismay, when geared for power, it wasn't any harder to stop than when geared for speed -- I suspect that it doesn't have very good traction (as there really isn't much mass pushing down on the wheels).

It would be nice to be able make quantitative statements about how much force (and thus, how much torque) a robot puts out. Does anyone know how I can do this? Would, for example, a spring scale or force gauge like one of these work well for this purpose, and if so, what is a good maximum rating to look for?

Answer by Clinton Blackmore for Good Microcontroller for Ethernet

2009-11-09T20:43:35Z

Regarding having a TCP/IP stack, there are two projects you should look at:

The Contiki Operating System

Contiki is an open source, highly portable, multi-tasking operating system for memory-efficient networked embedded systems and wireless sensor networks. Contiki has been used is a variety of projects, such as road tunnel fire monitoring, intrusion detection, water monitoring in the Baltic Sea, and in surveillance networks.

Contiki is designed for microcontrollers with small amounts of memory. A typical Contiki configuration is 2 kilobytes of RAM and 40 kilobytes of ROM.

The uIP TCP/IP Stack:

The open-source uIP TCP/IP stack provides TCP/IP connectivity to tiny embedded 8-bit microcontrollers, with maintained interoperability and RFC standards compliance.

Answer by Clinton Blackmore for I'd like to learn how to make my own USB gadgets

2009-11-09T17:59:26Z

Another device I've wanted to look into is the AT90USBKey. It has been a while since I've looked into it, and I'm not certain if you can program for it without Windows, but it will act as a USB device (like a keyboard or mass storage device) or as a USB host that you plug other devices into. There are sample programs available, and it looks reasonably easy to work with, provided you know a little bit about electronics and can code in C.

A google search for AT90USBKey and Linux yileds promising results.

I know you can get it from DigiKey.ca. I looked up a digikey equivalent for Asia; you can get the part from Farnell.

Answer by Clinton Blackmore for I'd like to learn how to make my own USB gadgets

2009-11-07T14:25:51Z

The Arduino is really popular, and it is open-source hardware, so there are variations, including the third-party Freeduinos called Bare Bones Board, the Really Bare Bones Board, and the Boarduino, which are very nice for using with breadboards. The standard Arduino is adapted using things called Shields. You can make your own breadboard shield or buy something like this ProtoShield Kit.

The Arduino uses an FTDI USB-RS232 chip or cable. [The standard Arduino has it build in, while the most of the bread board ones use a special cable that has the chip inside, and saves you some money.] There is a built-in driver for Linux, and Mac OS X and Windows users can download a driver. Effectively, this means that the Arduino acts as a device communicating on a serial port, and so it is very easy to communicate with.

To use it, you also download software. It comes with an IDE, an AVR-GCC toolchain, a really nice library, and software to upload your program on to the chip. It hides most of the details from you, and has a great community. It is programmed in a language called "Wiring", but it is really C++.

Lastly, being open-source hardware, there are schematics out there. Indeed, I seem to recall reading that it was fairly easy to build an earlier model. Searching for "Arduino schematics" in your favourite search engine will give you good results.

As for kits, the Maker Shed offers a lot of Arduino-related items in stock. They appear to ship around the world. Some ones of interest include:

The Shoppe at Wulfden (USA) has a nice experimenters kits, and appears to ship internationally.

Solarbotics (Canada) has a ARDX Arduino Experimenter's Kit, a Freeduino Starter Bundle - Ultimate and an Arduino Starter Bundle - Basic (and Ultimate), and appears to ship internationally.

The main Arduino's "buy" page lists Arduino vendors in all areas of the globe.

Other places I would check include Adafruit Industries (in the US), HVW Technologies (in Canada), and Sparkfun Electronics (in the US).

Answer by Clinton Blackmore for BlinkM temperature indicator

2009-11-05T22:26:00Z

The link to the write-up went through a re-direct and doesn't come out right. I do believe it is this:

ValenThrowieM + TempM

Answer by Clinton Blackmore for Iphone hardware serial port access

2009-11-03T02:01:33Z

This looks like what you want:

http://devdot.wikispaces.com/Iphone+Serial+Port+Tutorial

Answer by Clinton Blackmore for Using the iPhone to control a remote controlled car via Arduino

2009-11-02T22:30:03Z

The biggest problem you've got is how to get data from the iPhone to the Arduino. The main possibilities are to:

Physically interface the iPod Touch/iPhone to the Arduino. (See this thread).
Send a signal from the iPod Touch/iPhone via WiFi (or, I believe, from the iPhone via Bluetooth) to a computer (likely running a webserver) or directly to the Arduino (provided it has additional hardware to receive bluetooth or WiFi signals.) (See this blog entry).

Answer by Clinton Blackmore for Joystick with the Arduino

2009-11-02T22:20:05Z

I'm assuming you are using a non-USB joystick.

See http://www.built-to-spec.com/blog/2009/09/10/using-a-pc-joystick-with-the-arduino/

Answer by Clinton Blackmore for Applescript and Arduino

2009-11-01T01:48:09Z

The USB cable used to connect your Mac to the Arduino acts as a serial port, and can be used for communication. (For example, see Make an Arduino talk to your Mac).

Here is a thread that appears relevant: AppleScript serial communication with arduino

Or, you could go see this blog entry: Arduino-serial: C code to talk to Arduino. You could compile the application [downloading xcode, first, if needs be] and then use it to communicate from applescript by using the "do shell script" command.

Answer by Clinton Blackmore for IR Remote code for Arduino

2009-11-01T01:55:56Z

This might help: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1209565937

I suspect the Mac Mini will not respond to the same sort of signals that your audio equiptment does.

Comment by Clinton Blackmore

2010-05-27T20:11:36Z

It is easier to use Catenary with Build Your Own Blocks. See robotclub.ab.ca/blog/27/…

Comment by Clinton Blackmore

2010-03-31T23:12:34Z

Interesting. Unfortunately, it does not look like something I can leverage for my purposes.

Comment by Clinton Blackmore

2010-03-31T21:36:26Z

Scratch will communicate with other programs via sockets! That's amazing!

Comment by Clinton Blackmore

2010-03-31T19:16:50Z

That's interesting. Interesting indeed.

Comment by Clinton Blackmore

2010-03-29T18:31:33Z

Oh, man, that's cool. I didn't even know I needed one until now! And it works as an AVR programmer, too.

Comment by Clinton Blackmore

2010-03-29T14:12:29Z

@DoxaLogos - I'm glad I could share. I can't wait to here what you and others come up with.

Comment by Clinton Blackmore

2010-03-25T20:33:50Z

@endolith The chart on ikalogic.com/H_bridge_1.php shows the four modes of operation of an H-Bridge -- the motor turns forward/clockwise, the motor turns in reverse/counter-clockwise, the motor has active braking applied to it, or the motor is freewheeling or coasting.

Comment by Clinton Blackmore

2010-03-25T16:14:32Z

@endolith Really? I'd never heard of doing that. I can see that it could be done if you had a chip on the other end to decode the signal and re-encode it on two pins (foward/backward and a new PWM signal) sent on to an H-Bridge.

Comment by Clinton Blackmore

2010-03-24T23:23:26Z

That's a nice little bot.

Comment by Clinton Blackmore

2010-03-24T17:49:42Z

Wow! I'm going to have to look into that some more.

Comment by Clinton Blackmore

2010-02-15T19:47:08Z

A car battery is 50 AH? Good heavens.

Comment by Clinton Blackmore

2010-02-04T17:38:19Z

An excellent idea. Thank you.

Comment by Clinton Blackmore

2010-02-04T17:37:02Z

Now that is interesting. I happen to have some Shapelock, and I really haven't done much with it. (At the moment, I'm just trying to build a simple robot, as a practice before trying to build a rather larger robot. If I actually get anywhere with this, and remember, I'd be happy to post some details.)

Comment by Clinton Blackmore

2010-01-01T15:07:43Z

How did you get RRDtool installed? Did you compile RRDtool and its dependencies from source, use fink/homebrew/etc, or find pre-compiled binaries?

Comment by Clinton Blackmore

2009-12-27T15:46:45Z

I'd say, 'let me send the data in parallel, then', but the microcontrollers I want to use probably aren't fast enough to really make it worthwhile.