I spent yesterday morning working on the datalogger, specifically making it WiFi capable. This morning, I slept in, made my coffee and checked the news. Over on Hackaday, Jose has created an Arduino/Pi/WiFi/X-Bee environmental monitor. He's got his own webspace, uc4fun, where he's hosting the notes on his project. A lot more professional looking than mine.
He's essentially doing my project (If he knows I exist, he's shaking his head saying "That guy's doing MY project"). However, he's doing it in a completely different fashion, which is awesome. I think he's using a mix of I2C sensors (he's using the TMP102 and the BMP085) and a Sparkfun humidity sensor (Dude! New Product Friday.... 'cuse me while I go browse...).
I think he went with the doubled up microprocessor approach because it allows him to use the ADC's on the Arduino. So far, I've been severely limited in the sensors I can use on my build because I'm only using I2C and binary digital sensors. His complexity gets him some serious advantages, but is also one of the main things I want to avoid (He's probably writing code for both the Arduino and the Pi. That'll give me headaches). I sent him a message on the Hackaday board asking why he made the choices he did. Looking at his build and presentation, he's going to have some good answers.
I definitely wanted to avoid the multiple radio links. Given my history with RF links, I'd like to keep that as simple as possible.
Showing posts with label Technology. Show all posts
Showing posts with label Technology. Show all posts
Friday, January 11, 2013
Monday, December 3, 2012
GPIO Pins on the Adafruit Pi Cobbler
I posted the code for the program I used over in the Adafruit Forums: Raspberry Pi Home Datalogger (new window)
I'm cleaning the project up a little bit. I'm trying to make the code "nicer" and easier to follow (I should comment my code.... one of these days). I switched the code that runs the programs over time to a system that checks the time every second, executing specified code at the top of the minute (Poll the temperature and pressure sensors), and at the top of the hour. It works, but my system utilization never drops below 60%, and is frequently at 97%. I may have to go back to having the system "sleep" in between sensor checks. I think that's a bad way to do it, but I'd like to look at having these little nodes be battery and/or solar powered.
I messed around with the RPIO program I was screwing around with. I wanted to see which RPIO reported pins correlated with which pins labeled on the Cobbler T-Plate.
The chart is repeated over on the Adafruit forums, in the comments section of the code.
Cobbler RPIO
#4------ 7
#17----- 11
#18 -----12
#21 -----V1 13
#22 -----15
#23 -----16
#24 -----18
#25 -----22
#27 -----V2 13
I'm cleaning the project up a little bit. I'm trying to make the code "nicer" and easier to follow (I should comment my code.... one of these days). I switched the code that runs the programs over time to a system that checks the time every second, executing specified code at the top of the minute (Poll the temperature and pressure sensors), and at the top of the hour. It works, but my system utilization never drops below 60%, and is frequently at 97%. I may have to go back to having the system "sleep" in between sensor checks. I think that's a bad way to do it, but I'd like to look at having these little nodes be battery and/or solar powered.
I messed around with the RPIO program I was screwing around with. I wanted to see which RPIO reported pins correlated with which pins labeled on the Cobbler T-Plate.
The chart is repeated over on the Adafruit forums, in the comments section of the code.
Cobbler RPIO
#4------ 7
#17----- 11
#18 -----12
#21 -----V1 13
#22 -----15
#23 -----16
#24 -----18
#25 -----22
#27 -----V2 13
Monday, November 19, 2012
Raspberry Pi Home Datalogger
I've wanted to do something like this since I first started playing with microprocessors. The idea of an inexpensive, distributed sensor network throughout the house is really cool. In Hollywood we always see someone sitting at their computer console accessing their security system. It's typically a wire-frame display with sensors all over the place. They're getting all kinds of data, and even providing the occasional remote output (displays, lights or sirens, etc).
The $35 Raspberry Pi is almost the ideal basis for this kind of sensor network. It runs a (relatively) well developed Linux distribution. It has two USB ports, runs on 5v, sports an ethernet port, and will support almost any video display out there. More importantly, it has several exposed general purpose I/O pins and supports I2C.
I'm using Lady Ada's Occidentalis distro. So far it has been incredibly stable (though it swaps between video outputs if I cut power to the system). I'm using this distro because there are examples using Python to access the various GPIO's and the I2C.
My previous post detailed some of my earlier experiments with the system. Since then, I have worked on building a series of programs to access a BMP085 board attached to the I2C bus. I haven't done much with Python in quite awhile, so I'm fairly rusty and lacking a definite style.
I finished a series of programs last night that check the sensor, log the sensor data to a logfile and update a webpage, and a simple program to automate the whole process. Currently I've got the sensor being checked and logged every minute. The logger program is using the Python Logging module. I'm recording the event level (I'm generating a warning if the temperature reaches 30c), the epoch time (to facilitate graphing later), and the temperature and pressure (I don't care about the altitude). Using epoch time versus Python's asctime also saves some memory. The log files are between 1.8 and 18 megabytes per day (one measurement per minute). This yields recordings between 50-500 days per gigabyte. I'm not sure why there is such an insane difference between "Total Size of Files" and "Size on Disk". Given that it's close to an order of magnitude, I need to address that at some point.
I'm looking to increase the number of sensors on the board. I'm playing around with a GY-80 board that I got off of eBay some time ago. It includes the BMP085 sensor, plus an IMU/Gyro component with a compass. It was about $20. I'm wondering if the resolution is tight enough to work as a seismograph, though I'll have to increase the polling rate to something much higher than once a minute. Luckily, with the processing power of the Raspberry Pi, I could poll the sensor very quickly, analyze the data locally, and only report data that was relevant. This idea is going to be an add on after some of the other to-do list is achieved.
A big thank you to the write of the Giuseppe Urso Blog. He's found the datasheets for all of the components on this board (I think). The ebay seller has not been able to provide good information for me.
Things to do:
I want to improve the webpage. Right now it's a simple Apache text page that shows the temperature and pressure, along with the system time of the latest measurement (actual time, not epoch time).
I want more sensors. I'd like a light and motion sensor (again, we're trying to get close to that Hollywood sensor system). It would be great to incorporate a smoke/carbon monoxide/gas sensor into this build. A networked, web-enabled hazard detector would be incredible. I've already got a couple of sensors for this. To get them to work, I need to grab something that will let me add analog to digital feeds to the board (perhaps this?).
I really think I'd like to incorporate a second temperature sensor. I'd like my first sensor node to be located just inside the front door. Running a cable outside to a sensor (MPL115A2) would be pretty easy, and would give me the ability to log the weather outside compared to the environment inside. The capability would also be nice if Angel decides to start working with herps again. This would allow us to monitor the inside and outside of the tank.
The webpage needs serious work. I'd like to be able to generate graphs of the data, on the fly (click on the parameter, and it brings up a graph of the last hour. Click on that graph it shows the last 12 hours. Click on that, it shows the last day. Week, month, year, etc). My skills with Python are not up to the task yet. Hell, my skills with HTML are essentially non-existent (My webpages in the past have all used Dreamweaver). I need to see if I can merge the two, and someone get the Python code to play nicely with a Dreamweaver generated page.
Automated alerts. We'll go back to the Hollywood example for this one: When the bad guys are breaking in, I need the network to tell my cellphone (or bring up an alert on my computer). A more practical concept: When the house gets too hot, I need to be told. When the house is on fire, I need to be screamed at.
I want to keep the cost down. The average cost, per node, should be less than $100. At this price point, folks can afford to pick up a couple of nodes to watch their doors. As they like it more, they could grab additional nodes for other rooms in the house (I want to be able to control my small home theater system using my cellphone and an IR equipped node).
Webcam support. The Pi has two USB ports. Once the node is developed, there is no reason to have the USB ports in use. A web cam is a cheap (I saw a couple for under $10 the other day) way to gain tremendous amounts of information about a locale. Even if the camera is only used to snap stills to send to a remote site (or just log locally) the idea has tremendous value. As it stands, I haven't even tried hooking up a camera to the USB ports.
Free and open code. An idea like this is only as usable as the guy making everything. I'm not an engineer or computer scientist. If I could get a couple of those guys interested in the project, they'd be able to do incredible things with it. More to the point, they'd see ideas that I'd never even consider. This project, as an open source project, has real potential. I'm going to work on setting up a GitHub account, and making my code public (I'll warn you, it's ugly code).
I'll post up more as I get it.
Late edit: I'm starting to look at Lady Ada's Raspberry Pi WebIDE. I spent the afternoon/evening learning BitBucket, and now I've got a BitBucket account with the code on it (PiLog). I may not be doing things correctly, so the repository may be a little bizarre over the next couple of days. The code that was loaded tonight was tested to work, though your mileage may vary.
The $35 Raspberry Pi is almost the ideal basis for this kind of sensor network. It runs a (relatively) well developed Linux distribution. It has two USB ports, runs on 5v, sports an ethernet port, and will support almost any video display out there. More importantly, it has several exposed general purpose I/O pins and supports I2C.
I'm using Lady Ada's Occidentalis distro. So far it has been incredibly stable (though it swaps between video outputs if I cut power to the system). I'm using this distro because there are examples using Python to access the various GPIO's and the I2C.
My previous post detailed some of my earlier experiments with the system. Since then, I have worked on building a series of programs to access a BMP085 board attached to the I2C bus. I haven't done much with Python in quite awhile, so I'm fairly rusty and lacking a definite style.
I finished a series of programs last night that check the sensor, log the sensor data to a logfile and update a webpage, and a simple program to automate the whole process. Currently I've got the sensor being checked and logged every minute. The logger program is using the Python Logging module. I'm recording the event level (I'm generating a warning if the temperature reaches 30c), the epoch time (to facilitate graphing later), and the temperature and pressure (I don't care about the altitude). Using epoch time versus Python's asctime also saves some memory. The log files are between 1.8 and 18 megabytes per day (one measurement per minute). This yields recordings between 50-500 days per gigabyte. I'm not sure why there is such an insane difference between "Total Size of Files" and "Size on Disk". Given that it's close to an order of magnitude, I need to address that at some point.
I'm looking to increase the number of sensors on the board. I'm playing around with a GY-80 board that I got off of eBay some time ago. It includes the BMP085 sensor, plus an IMU/Gyro component with a compass. It was about $20. I'm wondering if the resolution is tight enough to work as a seismograph, though I'll have to increase the polling rate to something much higher than once a minute. Luckily, with the processing power of the Raspberry Pi, I could poll the sensor very quickly, analyze the data locally, and only report data that was relevant. This idea is going to be an add on after some of the other to-do list is achieved.
A big thank you to the write of the Giuseppe Urso Blog. He's found the datasheets for all of the components on this board (I think). The ebay seller has not been able to provide good information for me.
Things to do:
I want to improve the webpage. Right now it's a simple Apache text page that shows the temperature and pressure, along with the system time of the latest measurement (actual time, not epoch time).
I want more sensors. I'd like a light and motion sensor (again, we're trying to get close to that Hollywood sensor system). It would be great to incorporate a smoke/carbon monoxide/gas sensor into this build. A networked, web-enabled hazard detector would be incredible. I've already got a couple of sensors for this. To get them to work, I need to grab something that will let me add analog to digital feeds to the board (perhaps this?).
I really think I'd like to incorporate a second temperature sensor. I'd like my first sensor node to be located just inside the front door. Running a cable outside to a sensor (MPL115A2) would be pretty easy, and would give me the ability to log the weather outside compared to the environment inside. The capability would also be nice if Angel decides to start working with herps again. This would allow us to monitor the inside and outside of the tank.
The webpage needs serious work. I'd like to be able to generate graphs of the data, on the fly (click on the parameter, and it brings up a graph of the last hour. Click on that graph it shows the last 12 hours. Click on that, it shows the last day. Week, month, year, etc). My skills with Python are not up to the task yet. Hell, my skills with HTML are essentially non-existent (My webpages in the past have all used Dreamweaver). I need to see if I can merge the two, and someone get the Python code to play nicely with a Dreamweaver generated page.
Automated alerts. We'll go back to the Hollywood example for this one: When the bad guys are breaking in, I need the network to tell my cellphone (or bring up an alert on my computer). A more practical concept: When the house gets too hot, I need to be told. When the house is on fire, I need to be screamed at.
I want to keep the cost down. The average cost, per node, should be less than $100. At this price point, folks can afford to pick up a couple of nodes to watch their doors. As they like it more, they could grab additional nodes for other rooms in the house (I want to be able to control my small home theater system using my cellphone and an IR equipped node).
Webcam support. The Pi has two USB ports. Once the node is developed, there is no reason to have the USB ports in use. A web cam is a cheap (I saw a couple for under $10 the other day) way to gain tremendous amounts of information about a locale. Even if the camera is only used to snap stills to send to a remote site (or just log locally) the idea has tremendous value. As it stands, I haven't even tried hooking up a camera to the USB ports.
Free and open code. An idea like this is only as usable as the guy making everything. I'm not an engineer or computer scientist. If I could get a couple of those guys interested in the project, they'd be able to do incredible things with it. More to the point, they'd see ideas that I'd never even consider. This project, as an open source project, has real potential. I'm going to work on setting up a GitHub account, and making my code public (I'll warn you, it's ugly code).
I'll post up more as I get it.
Late edit: I'm starting to look at Lady Ada's Raspberry Pi WebIDE. I spent the afternoon/evening learning BitBucket, and now I've got a BitBucket account with the code on it (PiLog). I may not be doing things correctly, so the repository may be a little bizarre over the next couple of days. The code that was loaded tonight was tested to work, though your mileage may vary.
Thursday, October 16, 2008
Junk to Jewels
I'm a creative guy, but as an artist, I suck. I truly do not have a good eye for aesthetics (my best friend does, and it drives me crazy).
So when I set out to make something, it has to work. It may not look good, but it's going to work (and if it works, it typically works very well).
I build computers on the side. Friends and family get it for free, others pay a small amount, typically less than what they would be paying for a retail computer. Oh yeah, you don't have to wait an hour to get me on the tech support hot-line. And yeah, I do make house calls.
I've got a fair amount of compu-junk lying around in boxes, or attached to old projects (My last big build was a dedicated computer built into my truck. Full nav, MP3 player, position and speed tracker, on board diagnostics, a real nice system. Too bad I had to yank it when I sold the truck and bought a Prius). Much of it is older stuff that has been taken out of a computer or other project that is being upgraded. Every once in awhile, I get a new piece thrown my way.
This build started off as a "perfect storm". Everything came together rapidly. First, my sister bought me "Ironman" on Blu-Ray (great movie). Unfortunately, I don't have a Blu-Ray player or an HDTV. I went and did a little research, and those things are expensive, particularly if you want a good player:
I specifically wanted one that could output to a variety of sources, and would connect to a home network (it turns out that this last option is kinda rare, and not cheap). I was looking at hundreds of dollars, probably over $500.
As a lark, I researched Blu-Ray drives for PC's. While searching, I took a look at Blu-Ray recorders, and found a unit from LG for $190, including free media:
A Blu-Ray burner, for under $200? This project started to have a pulse.
A friend of mine had recently told me he was going to give me a motherboard that he had bought for his office computer. He had purchased the wrong one, and in exchange, I would help him get the right one (turns out he was doing something similar, he wanted to use his PC on his big HDTV on the wall). So, I was getting a buff new board, from my favorite MOBO company (ASUS).
Free
A friend had given me a shuttle PC case and power supply a couple of years before. I'd never had a MOBO for it, but that was getting taken care of. I went and grabbed it out of storage, and it looked perfect. Unfortunately, it's a couple of years old, so I don't really have a weblink for it.
Memory was going to be salvaged, along with the processor (Intel Q6600) from an older motherboard. As it turns out, the memory was not compatible with the new motherboard, so I had to get new sticks (thank god they're really cheap).
The price is off on the website, mine was $50 with another rebate on top of that.
The fan also had to be replaced. The fan on the old motherboard was too tall for the shuttle PC case. I splurged a little here, and got a Zalman fan with a 16dB sound rating, for $34 (Thermal paste another $7). I was a little worried that it was going to be too broad for the motherboard, but it fit beautifully. Even at it's highest setting I can't hear the fan noise over the background noise in my bedroom/office. Certainly when the TV is on, I won't be able to hear it.
I salvaged another graphics board from an old PC. This board (a Radeon x1600) had a VGA, DVI and S-Video output. The S-Video is what I really needed (The MOBO has VGA, DVI, and HDMI outputs. Unfortunately the DVI is not a full DVI output) to be able to get the computer to display on a standard TV.
So, the build was broken down like this:
ASUS P5Q-EM Motherboard Free
Intel Q6600 Processor Free
ATI Radeon x1600 Free
Zalman Fan and thermal paste ~$42
Corsair 4gb Memory ~$50 (minus a rebate)
LG Blu-Ray Recorder Drive $190
Windows Vista Ultimate Free from old computer
Total cost: $282 (I missed my original price point of $250 by
$32)
I choose Vista because XP doesn't support Blu-Ray drives (or playback). I also happened to have an extra license from an old computer that wasn't going to get ressurected (at least not right away). I also have had pretty good experiences with Vista to date, and I'm not really sure what the griping is about (though I'll admit I would have like to see more of the promised features in the upgrades).
I'd like to thank the ASUS community forums real quick. The memory incompatibilty issue really stumped me. When I first started testing the board, it powered up, but nothing came on with the monitor. This isn't my first build, so I spent quite awhile (hours) trying to figure out what was wrong. Within hours of posting a plea to the forum community, I had a simple answer (that I probably should have come up with), and my fix was evident. This is one reason why I keep going back to ASUS.
Once that was taken care of, installation was a snap. I initially installed using a dedicated computer monitor. I wanted to get the system up, drivers installed, and everything working before attempting to connect the computer to a TV set.
Once that was accomplished, I set the screen resolution down to 640x480. I then shut the system down, and hooked the video and sound up to the TV. Lo and behold, the Windows boot logo came up, and the desktop appeared.
I put in Ironman, which immediately booted through PowerDVD (bundled with the Blu-Ray drive). Ironman immediately accessed the internet and pulled down additional content (pretty cool, but I have no idea what it actually pulled down). I watched the first scene, and fell asleep, happy with my build.
I finished watching Ironman the next day. While I'm really pleased with the build, I can't wait to see what this looks like on a true HDTV. That's probably going to be a really long time in coming, as I had to reach deep just to finish this build (I'm actually a poor, not-quite-starving college student).
The interface is a little difficult. I need to find a way to make my Harmony remote control the media functions of the PC. I also need to find a decent wireless media keyboard for the system (my old Media Center Keyboard apparently has had a stroke or something).
I don't know that this is a viable option for the majority of the people out there. Cost is close to a real unit:
Case ~$100
Processor ~$75
Memory ~$50
Motherboard ~$140
Operating System ~$150 (at least)
Blu-Ray Recorder ~$200
So around $700, call it $850-$900 with labor. However, this system will RECORD to Blu-Ray disks (and CD's, DVD's, dual layer disks, and lightscribe). It's incredibly hard to find Blu-Ray recorders for home theaters, and the ones I found ranged from $1000-$2,500. Granted, that price is going to come down tremendously over the years.
However, this system will also do everything that a normal PC will do (email, internet, etc). With the addition of a TV tuner board:
This thing will also be able to act as a TiVo/DVR (Approximately $150). It won't be able to get premium channels (yet), because the consumer electronics industry hasn't jumped on the capabilities of the CableCard system yet (that's a rant for a later day).
I need to figure out how to get movies from this system to my iPod. I've never watched a movie on my iPod (I don't really sit still long enough to do that), but I'd like to be able to do it. Also, the Genius's at the Apple Store told me I couldn't.
Don't tell me "no". It just eggs me on.
Be safe out there, and remember to vote.
Edit: Quick update. I under clocked the processor to run at 1.2Ghz (half the normal speed), which dropped the CPU temperature from 36-39 degrees centigrade, down to 26-29 degrees centigrade with the fan now running at the lowest setting. Video playback seems to be unaffected, but the boot times seem to be slightly longer.
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