Sciencemadness Discussion Board » Special topics » Technochemistry » Microcontrollers & The Amateur Chemist Select A Forum Fundamentals   » Chemistry in General   » Organic Chemistry   » Reagents and Apparatus Acquisition   » Beginnings   » Responsible Practices   » Miscellaneous   » The Wiki Special topics   » Technochemistry   » Energetic Materials   » Biochemistry   » Radiochemistry   » Computational Models and Techniques   » Prepublication Non-chemistry   » Forum Matters   » Legal and Societal Issues

Pages:  1  2    4
Author: Subject: Microcontrollers & The Amateur Chemist
IrC
International Hazard

Posts: 2710
Registered: 7-3-2005
Location: Eureka
Member Is Offline

Mood: Discovering

http://www.ebay.com/itm/Mini-ATMEL-AVR-ATMEGA-STK500-USB-ISP...

Right now you can get a nice Mini ATMEL AVR ATMEGA STK500 USB ISP Programmer for almost $49 off normal price. I do not know how long the sale will last but I ordered one from this ebay seller while the price was this low. Looks like He has plenty in stock right now. "Science is the belief in the ignorance of the experts" Richard Feynman bfesser Resident Wikipedian Posts: 2114 Registered: 29-1-2008 Member Is Offline Mood: No Mood I'm betting that those are the counterfeit ones I've heard about. I've been struggling to get one of the SparkFun <a href="https://www.sparkfun.com/products/9825" target="_blank">Pocket AVR Programmers</a> <img src="../scipics/_ext.png" /> to work over the last couple weeks. Does anyone here have any experience with these? I've drawn the conclusion that purchasing one of these was a mistake. All I want to do with it at this point is flash updated code to the <a href="http://www.atmel.com/images/doc2543.pdf" target="_blank">ATtiny2313</a> <img src="../scipics/_pdf.png" /> in my <a href="viewthread.php?tid=25882">Geiger counter kit</a>. I'm about ready to withdraw a little from my savings account and order a proper <a href="http://store.atmel.com/PartDetail.aspx?q=p:10500054#tc:description" target="_blank">AVRISP mkII</a> <img src="../scipics/_ext.png" /> [Edited on 18.9.13 by bfesser] arsphenamine Hazard to Others Posts: 236 Registered: 12-8-2010 Location: I smell horses, Maryland, USA Member Is Offline Mood: No Mood  Quote: Originally posted by bfesser I'm about ready to withdraw a little from my savings account and order a proper AVRISP mkII Get the AVRISP mkII at ~$35 from AVR, Mouser, Digikey, Newark, et.al.

The Arduino development environment supports it, as does the Windows Atmel Studio. Think of it as the gold standard for AVR embedded flashing.

The only thing you need to remember is that it will overwrite the bootloader in an otherwise serviceable Arduino.

--
bfesser
Resident Wikipedian

Posts: 2114
Registered: 29-1-2008
Member Is Offline

Mood: No Mood

Rotary Telephone Pulse to DTMF with PIC

I've got another (unrelated) project going...

Yesterday, I picked up an old <a href="http://en.wikipedia.org/wiki/Rotary_dial" target="_blank">rotary dial</a> <img src="../scipics/_ext.png" /> telephone (ITT 500, made in Canada) from the local surplus shop, which I plan to restore and gift to my father. After a little research, I've found that <a href="http://en.wikipedia.org/wiki/Pulse_dialing" target="_blank">pulse dialing</a> <img src="../scipics/_wiki.png" /> is no longer supported by the service provider my parents subscribe to. [curses newfangled technology&mdash;everything's fucking digital now...]

I managed to find a <a href="http://bygselvhifi.dk/misc/telephone-pulse-to-dtmf-converter/#!prettyPhoto[puls2dtmf]/1/" target="_blank">neat little circuit</a> <img src="../scipics/_ext.png" /> that I'd like to try out which will generate <a href="http://en.wikipedia.org/wiki/DTMF" target="_blank">DTMF</a> <img src="../scipics/_wiki.png" /> signals from the dial's pulses using a PIC12F675. On the bright side, this'll be a great opportunity for me to learn to etch PCBs&mdash;something I've been meaning to do for years. On the down side, I've invested my time and funds (unsuccessfully) toward <a href="http://en.wikipedia.org/wiki/Atmel_AVR" target="_blank">AVRs</a> <img src="../scipics/_wiki.png" /> up to this point, and have not worked with the <a href="http://en.wikipedia.org/wiki/PIC_microcontroller" target="_blank">PIC</a> <img src="../scipics/_wiki.png" /> &micro;Cs before.

Of course, there are many other ways I could go about converting the telephone, but none of them have the appeal and simplicity of this one. In addition, I'd like to preserve as much of the original circuitry and mechanics of the phone as possible, so replacing the guts with a RasPi or Arduino with direct <a href="http://en.wikipedia.org/wiki/Voice_over_IP" target="_blank">VoIP</a> <img src="../scipics/_wiki.png" /> is out of the question.

My question is this: Should I bother trying to build and program one of these myself and risk miserable failure (again), or should I just wait until I can afford to buy a commercial adapter?

[I didn't have a question before writing this&mdash;just needed to rant to let out my frustration.]

watson.fawkes
International Hazard

Posts: 2793
Registered: 16-8-2008
Member Is Offline

Mood: No Mood

 Quote: Originally posted by bfesser I managed to find a neat little circuit that I'd like to try out which will generate DTMF signals from the dial's pulses using a PIC12F675.
That "neat little circuit" is nothing but a power supply and a crystal frequency reference (possibly not even needed) for the microcontroller chip. All the pulse detection and tone generation is done in software. Nothing an AVR can't do, and all the software development could be done on a stock Arduino.
watson.fawkes
International Hazard

Posts: 2793
Registered: 16-8-2008
Member Is Offline

Mood: No Mood

 Quote: Originally posted by IrC Mini ATMEL AVR ATMEGA STK500 USB ISP Programmer
 Quote: Originally posted by bfesser I'm betting that those are the counterfeit ones I've heard about.
And what would that be a counterfeit of, exactly? It's a flash programmer for all the devices listed. Smells more like your prejudice against the Chinese again, rather than anything about the device itself.
phlogiston
International Hazard

Posts: 1350
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline

Mood: pyrophoric

Although some people can debate endlessly about the differences between AVR's or PIC's, the reality is that there is not all that much of a difference. There is a wide range of each series available with similar peripherals, for similar cost.
If you have invested in AVR tools and built up some experience with it, why change? Especially for a simple application like a DTMF generator, the simplest chips of either range can do the job, both at a cost of less than 1 Euro.
I use PICs mostly myself, primarily because I have grown familiar with their design and peculiarities. They are very cost effective. The microcontroller part of my circuits is usually less than Eur 2,-. I don't think the Arduinos come close to that yet, but I must admit I haven't checked anytime recently.

[Edited on 18-9-2013 by phlogiston]

-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer
watson.fawkes
International Hazard

Posts: 2793
Registered: 16-8-2008
Member Is Offline

Mood: No Mood

 Quote: Originally posted by phlogiston I use PICs mostly myself, primarily because I have grown familiar with their design and peculiarities. They are very cost effective. The microcontroller part of my circuits is usually less than Eur 2,-. I don't think the Arduinos come close to that yet, but I must admit I haven't checked anytime recently.
The small chips in the AVR series uses are about the same price, depending on chip features. The Arduino itself isn't nearly as cheap, but it's a development board, even if it's inexpensive enough for some folks just to embed one in their projects.
bfesser
Resident Wikipedian

Posts: 2114
Registered: 29-1-2008
Member Is Offline

Mood: No Mood

 Quote: Originally posted by watson.fawkes And what would that be a counterfeit of, exactly?
Of the genuine article. The one whose revenue goes to pay the salaries of the hard-working software and electrical engineers who designed and developed it&mdash;not to some corrupt Chinese elite who owns a factory shamelessly producing <a href="http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=59447&start=0&postdays=0&postorder=asc&highlight=" target="_blank">knockoffs and counterfeits</a> <img src="../scipics/_ext.png" /> and violating copyrights and patents out of sheer greed.
 Quote: Smells more like your prejudice against the Chinese again, rather than anything about the device itself.
Don't try to start that bullshit argument again&mdash;not here. If you're so confident in the quality, why don't you purchase the one linked to with your own money, try it out, and get back to us (if and when it finally arrives in the post)?

 Quote: Originally posted by phlogiston If you have invested in AVR tools and built up some experience with it, why change?
Because I've invested in what are apparently defective and useless tools and my experience with AVRs so far (aside from the Arduino) has been anything but positive. Regardless, thank you for your input, <strong>phlogiston</strong>

watson.fawkes
International Hazard

Posts: 2793
Registered: 16-8-2008
Member Is Offline

Mood: No Mood

Quote: Originally posted by bfesser
 Quote: Smells more like your prejudice against the Chinese again, rather than anything about the device itself.
Don't try to start that bullshit argument again&mdash;not here.
I didn't start it, you started it by posting prejudiced comments. The only reason that you think it's bullshit is that you are apparently completely incapable of recognizing that you could be in error in any significant way.

 Quote: Originally posted by bfesser If you're so confident in the quality, why don't you purchase the one linked to with your own money, try it out, and get back to us (if and when it finally arrives in the post)?
I own one. It arrived just fine, albeit slowly, as all naval EMS packages do. I haven't had occasion to use it yet.

It's not a counterfeit, since it's not labelled as an Atmel product. And if you think that knockoffs are somehow wrong, you're discounting that the continuing dominance of the PC market started with predominantly US-based knockoffs of the IBM PC (such as Compaq). Atmel's not crying over the product I've got; it's got two AVR chips in it. And furthermore it promotes higher sales of AVR chips.

So do you have evidence that these clone devices have infringed copyrights of the board mask or the software? Do you have evidence that it wasn't independently developed? It's a simple circuit, and the AVR tool chain is open source. There's no inherent right to be able to keep innovation to yourself, and to think otherwise is to fight reality and lose.
arsphenamine
Hazard to Others

Posts: 236
Registered: 12-8-2010
Location: I smell horses, Maryland, USA
Member Is Offline

Mood: No Mood

 Quote: Originally posted by phlogiston Although some people can debate endlessly about the differences between AVR's or PIC's, the reality is that there is not all that much of a difference. There is a wide range of each series available with similar peripherals, for similar cost.
Speaking as someone who wrote device control software in assembly language for ~10 years, I beg to differ. I wanted to like the PIC but its haphazard architecture and overpriced development tools made it a non-starter back when it mattered.

The PIC I/O and its control are a disorganized collection of features that militate against any ready use. Even Intel's 80186 was better thought out. Don't get me started about PIC asm mnemonics. Any C language wrapper will be an ugly mess of special features just to get an ordinary job done. It's only a question of degree and how well the abstraction suggests the underlying hardware.

AVR's ATmegas are considerably easier to use, the tools are cheap or free (as in beer), and the learning curve is shallow and fast if you already know C.
bfesser
Resident Wikipedian

Posts: 2114
Registered: 29-1-2008
Member Is Offline

Mood: No Mood

Well, I used to code C++, and have had no problem with C for the Arduino. It sounds like I'd be better off focusing on the Atmel AVRs, rather than dividing my attention between the two. Thank you for your advice. I'll probably invest in a decent programmer soon, and hope to get one of my old computers running Linux to make things easier.

arsphenamine
Hazard to Others

Posts: 236
Registered: 12-8-2010
Location: I smell horses, Maryland, USA
Member Is Offline

Mood: No Mood

 Quote: Originally posted by bfesser Thank you for your advice. I'll probably invest in a decent programmer soon, and hope to get one of my old computers running Linux to make things easier.
If Windows owns your primary computer, download AVR Studio. There are online tutorials for programming the Arduino with it. If you have a USB port, you don't need a programmer ... yet.

When your Arduino prototype is done, you can embed the program on the \$20 Teensy which is the size of a commemorative stamp.

Plan B is to use the Coridium ARM7 board and its interpreted BASIC. Rapid prototyping gets you farther faster than MIPS.
bfesser
Resident Wikipedian

Posts: 2114
Registered: 29-1-2008
Member Is Offline

Mood: No Mood

I found a similar circuit+code for AVR:

Attachment: PulseToTone_2012_01_22.zip (414kB)

For completeness, here's the PIC one:

Attachment: pulse2dtmf2.zip (111kB)

[edit: typo]

[Edited on 20.9.13 by bfesser]

PeeWee2000
Hazard to Self

Posts: 58
Registered: 2-7-2013
Location: Michigan
Member Is Offline

Mood: No Mood

Hey bfesser I bought the pocket avr programmer from sparkfun about a year back to attempt to program some attiny85 chips but never had any success with it so theres a good chance it is the programmer but I'd like to think not as sparkfun seems like a pretty reputable site to me but looks can be deceiving :/

And also I think having an arduino \ uC in the lab would be great, Id love to have a set up that measures the temperature at various points in my apparatus and automatically turns the hotplate off when it detects a temperature rise! Unfortunately I never really learned how to program so its been kind of a pipe dream but if other people more knowledgeable in programming helped out Id love to help make it happen. I do however have plenty of experience in electronic circuits so putting things together is no problem.

“Everything is relative in this world, where change alone endures.”

― Leon Trotsky
bfesser
Resident Wikipedian

Posts: 2114
Registered: 29-1-2008
Member Is Offline

Mood: No Mood

What timing! I didn't see your post until this morning, but I happened to be working on the AVR Pocket Programmer last night, and finally got it to work! Frustratingly, it turned out that the ribbon cable they supplied with the programmer was defective (open MOSI on the 6 pin plug). I won't get into how I figured this out, but I did manage to carefully disassemble the cable and re-wire it to work. Afterward, I spent a little time playing around with the programmer, and finally managed to flash some custom firmware onto blank ATTiny2313s for my Geiger counter.

I'm familiar with many programming languages, though I haven't kept up with it over the years (since changing majors from Computer Science to Chemistry). If there's any coding you'd like help with, just let me know and I'll be more than glad to have a look.

Tip: Type &amp;mu; or &amp;micro; for &mu;.

arsphenamine
Hazard to Others

Posts: 236
Registered: 12-8-2010
Location: I smell horses, Maryland, USA
Member Is Offline

Mood: No Mood

 Quote: Originally posted by bfesser I won't get into how I figured this out, but ...
It involved dogged persistence, a WTF moment, and a steady stream of creative profanity as you made the repairs, yes?
bfesser
Resident Wikipedian

Posts: 2114
Registered: 29-1-2008
Member Is Offline

Mood: No Mood

Yes. But it wasn't angry profanity, more relieved and joyful at finally getting the damned thing working. I plan to post on my modifications to the hardware and firmware of the Geiger counter soon (in <a href="viewthread.php?tid=25882">another topic</a>.

quantumchromodynamics
Hazard to Self

Posts: 67
Registered: 25-9-2013
Location: with much determination, nowhere in particluar
Member Is Offline

Mood: tired but still trying

hardware input and output

Specifically does anyone know of or have ideas about hardware that might attach to a drip valve of a separation funnel? A gear down stepper motor attachment? Is there an existing protocol for interconnecting heating mantles, stirrers, shaker tables, video reaction monitoring, etc? For me the software and the feedback control algorithms are the fun part. What seems missing are the sensors and the hardware to automate a reaction in glassware. RC airplane servo motors seem like a good start.
phlogiston
International Hazard

Posts: 1350
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline

Mood: pyrophoric

 Quote: Originally posted by arsphenamine Speaking as someone who wrote device control software in assembly language for ~10 years, I beg to differ. I wanted to like the PIC but its haphazard architecture and overpriced development tools made it a non-starter back when it mattered. ...snip... AVR's ATmegas are considerably easier to use, the tools are cheap or free (as in beer).

Indeed, opinions differ, and, sure, it could be made a little easier, but that's a minor issue. It's not -that- difficult. Everyone who can program can figure out how to program PICs in any language they like best. Development tools are also available for free, who told you otherwise? I've also enjoyed writing assembly for various processors and microcontrollers for about 15 years now and found the PIC series to be quite useful and cost effective.

-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer
arsphenamine
Hazard to Others

Posts: 236
Registered: 12-8-2010
Location: I smell horses, Maryland, USA
Member Is Offline

Mood: No Mood

Quote: Originally posted by phlogiston
 Quote: Originally posted by arsphenamine I wanted to like the PIC but its haphazard architecture and overpriced development tools made it a non-starter back when it mattered. ...snip... AVR's ATmegas are considerably easier to use, the tools are cheap or free (as in beer).

Indeed, opinions differ, and, sure, it could be made a little easier, but that's a minor issue. It's not -that- difficult. Everyone who can program can figure out how to program PICs in any language they like best. Development tools are also available for free, who told you otherwise? I've also enjoyed writing assembly for various processors and microcontrollers for about 15 years now and found the PIC series to be quite useful and cost effective.
The operative words are "back when it mattered" which was early in the millenium . CCS development tools were the least expensive at the time, but still a few hundred dollars and the PIC guaranteed a steep learning curve. No thanks.

GNU toolchain propagation changed that in only five years, for PIC, AVR, and ARM alike, but Massimo Banzi's C++ wrapper for the Arduino made it a no-brainer. I'm uninclined to grovel over the entirety of an architecture any more when all I need is a small simple appliance.

I don't assert that the Arduino is without flaw, only sufficiently easier to get up and running than I found the PIC to be. I wonder if any of them has a readily accessible CTC (clock timer counter) mode. You can do it with arcane frobbage of the Arduino, but it is exactly that: arcane because the documentation is thin on that point.

bfesser
Resident Wikipedian

Posts: 2114
Registered: 29-1-2008
Member Is Offline

Mood: No Mood

<strong>quantumchromodynamics</strong>, I have plenty of ideas, but it's more effort than it's worth. The laboratory glassware that we're all familiar with is designed to be manipulated by human hands. As far as I'm aware, when professional chemists want to automate things, they switch over to using purpose-built apparatus (Swagelok&reg; valves/fittings, stainless steel reactors, PTFE-lined pumps, and the like). While I'm sure we could come up with solutions to handle our solutions in 'regular' glassware, it would likely be easier (and cheaper) to use the appropriate kit. I'm no expert on the engineering side of Chemical Engineering, so perhaps someone else could chime in here.

IrC
International Hazard

Posts: 2710
Registered: 7-3-2005
Location: Eureka
Member Is Offline

Mood: Discovering

http://www.ebay.com/itm/pH-Circuit-Sensor-for-Arduino-/20077...

Has anyone tried this PH board for the Arduino?

"Science is the belief in the ignorance of the experts" Richard Feynman
bfesser
Resident Wikipedian

Posts: 2114
Registered: 29-1-2008
Member Is Offline

Mood: No Mood

IrC, I linked to Atlas Scientific in the first post of this topic. I emailed them a few weeks back to see if they could sell me one of those boards without the epoxy coating or pin headers. Long explanation short; they said 'no.'

<a href="https://www.atlas-scientific.com/product_pages/embedded/ph.html" target="_blank">pH Circuit</a> <img src="../scipics/_ext.png" /> (Atlas Sci.)
<a href="https://www.atlas-scientific.com/product_pages/components/arduino-shield.html" target="_blank">Arduino Shield</a> <img src="../scipics/_ext.png" />
<a href="https://www.atlas-scientific.com/product_pages/components/raspberry-pi-shield.html" target="_blank">Raspberry Pi Carrier Board</a> <img src="../scipics/_ext.png" />

IrC
International Hazard

Posts: 2710
Registered: 7-3-2005
Location: Eureka
Member Is Offline

Mood: Discovering

Been many months since I read this thread so I did not remember it but I still wonder if the board on ebay is worth buying. OK how about building a stirrer using an Arduino?

http://www.circuitsathome.com/mcu/programming/vigorius-stirr...

http://www.circuitsathome.com/mcu/programming/vigorius-stirr...

Also you would have extra lines to monitor and control temperature or maybe a color change in a reaction stopping (or starting) stirring or heat. Even controlling a dump of chemicals in a complex reaction where one may not wish to be standing near it. One could also dump a reaction into ice water if events get out of control. Using a temperature sensor, or the color recognition sensor (it could look for oxides of nitrogen due to their obvious color as example).

http://www.ebay.com/itm/1pcs-Color-Sensor-Color-Recognition-...

I just find it odd this is a fairly dead thread when the incredible number of uses abound for the Arduino (or other controller) as it relates to science. Maybe its just me but if I had access to the huge number of advances 50 years ago you people do today my entire lab would run itself while I watched old scifi reruns. Hell 50 years ago I didn't even have reruns.

OK I give your going to have to explain this as I have not had one to study yet:

"I emailed them a few weeks back to see if they could sell me one of those boards without the epoxy coating or pin headers. Long explanation short; they said 'no.'"

Looking at the pic I see it would take seconds to unsolder the headers right through the epoxy with my vacuum de-soldering head. I have had to do this many times in years past on waterproofed circuit boards. Examples are a metal detector and also HV supply boards for HeNe lasers. Often I had to remove and replace a part on the board, adding a clear epoxy coat after repair is done in the areas where I melted out the epoxy around the component pins.

Also wouldn't DCM remove the epoxy if one was very careful to not remove it in areas you did not wish to? I have done this on circuit boards hundreds of times in years past. Why do you need to remove it? Is it to get the board to fit somewhere else, and would a 90 degree bend on pins work if this was your reason? I can see why they would not, they likely have them manufactured in the Orient somewhere and cannot get boards mid production. Or they don't want you screwing with their design? Screwing with other peoples boards is not all that hard if this is their only reason.

One of these irons would remove the headers in seconds right through the epoxy without any harm to the board, leaving clean pads to solder wires or whatever it is you wanted to do. Just be careful near the chip resistor by the GND pin. All the others are out in the open and easy to do. After doing whatever it is you need to do, mix up a little clear epoxy and re-coat the areas where you melted the epoxy away. We're talking about a 15 minute job here no big deal.

[Edited on 10-23-2013 by IrC]

"Science is the belief in the ignorance of the experts" Richard Feynman
Pages:  1  2    4

 Sciencemadness Discussion Board » Special topics » Technochemistry » Microcontrollers & The Amateur Chemist Select A Forum Fundamentals   » Chemistry in General   » Organic Chemistry   » Reagents and Apparatus Acquisition   » Beginnings   » Responsible Practices   » Miscellaneous   » The Wiki Special topics   » Technochemistry   » Energetic Materials   » Biochemistry   » Radiochemistry   » Computational Models and Techniques   » Prepublication Non-chemistry   » Forum Matters   » Legal and Societal Issues