Comments for Eightlines Creations http://www.eightlines.com/blog Experiments in Physical Computing Fri, 21 Nov 2008 06:39:37 +0000 http://wordpress.org/?v=abc Comment on Data Logging to the Arduino EEPROM by blalor http://www.eightlines.com/blog/2008/09/data-logging-to-the-arduino-eeprom/#comment-107 blalor Mon, 17 Nov 2008 02:49:33 +0000 http://www.eightlines.com/blog/?p=45#comment-107 Just popped in here after finding your site through a subscription to the "arduino" technorati tag feed in Google Reader. How random. (Yes, I'm the afore-mentioned "blalor"). :-) Glad you're making progress! Brian Just popped in here after finding your site through a subscription to the “arduino” technorati tag feed in Google Reader. How random. (Yes, I’m the afore-mentioned “blalor”). :-)

Glad you’re making progress! Brian

]]> Comment on Data Logging to the Arduino EEPROM by Brent http://www.eightlines.com/blog/2008/09/data-logging-to-the-arduino-eeprom/#comment-105 Brent Sun, 16 Nov 2008 22:57:32 +0000 http://www.eightlines.com/blog/?p=45#comment-105 One of the biggest issues is storing a float in a byte isn't really possible. If you divide by 10 and receive an amount which contains a decimal you lose that precision. A real time clock is one of those things I wish the Arduino had. That way you could add a timestamp to the interrupt. But again, storing the datetime to a EEPROM takes space that it doesn't really have. One of the biggest issues is storing a float in a byte isn’t really possible. If you divide by 10 and receive an amount which contains a decimal you lose that precision.

A real time clock is one of those things I wish the Arduino had. That way you could add a timestamp to the interrupt. But again, storing the datetime to a EEPROM takes space that it doesn’t really have.

]]> Comment on Data Logger — Next Steps by Eightlines Creations › Mapping GPS Data http://www.eightlines.com/blog/2008/09/data-logger-next-steps/#comment-103 Eightlines Creations › Mapping GPS Data Sun, 16 Nov 2008 20:36:55 +0000 http://www.eightlines.com/blog/?p=73#comment-103 [...] with managing the size of the data in the allotted EEPROM space on board the Arduino. I built up an SDCard writer based on several specs I found in the messageboard and it worked flawlessly. I successfully [...] […] with managing the size of the data in the allotted EEPROM space on board the Arduino. I built up an SDCard writer based on several specs I found in the messageboard and it worked flawlessly. I successfully […]

]]> Comment on Data Logging to the Arduino EEPROM by Eightlines Creations › Mapping GPS Data http://www.eightlines.com/blog/2008/09/data-logging-to-the-arduino-eeprom/#comment-102 Eightlines Creations › Mapping GPS Data Sun, 16 Nov 2008 20:35:38 +0000 http://www.eightlines.com/blog/?p=45#comment-102 [...] project off I was having quite a few issues with managing the size of the data in the allotted EEPROM space on board the Arduino. I built up an SDCard writer based on several specs I found in the [...] […] project off I was having quite a few issues with managing the size of the data in the allotted EEPROM space on board the Arduino. I built up an SDCard writer based on several specs I found in the […]

]]> Comment on Data Logging to the Arduino EEPROM by Troy http://www.eightlines.com/blog/2008/09/data-logging-to-the-arduino-eeprom/#comment-101 Troy Wed, 12 Nov 2008 20:28:29 +0000 http://www.eightlines.com/blog/?p=45#comment-101 Re the quoted text below: 1) do you need the resolution of each wheel revolution? what about dividing revolutions by 10? That's a much smaller number to track, just multiply by 10 later to rehydrate. 2) for the sample rate instead of every minute can you store your average and when that changes log the new average with a timestamp? It's more bits per sample but possibly way less samples overall. --- "The EEPROM was the next issue. 512 bytes is a serious limitation. Some math was required to see if I what wanted to do was even possible. If I were to poll every minute over a ride I’d be able to record 8.5 hours of one byte readings. That’s pretty good, seeing a 200km ride would take approximately 6 hours. One byte is capable of storing 256 possible values. Is that enough, or would I need more values? If my revolutions were 255 with a wheel circumference of 2110mm I’d be traveling an average speed of 32km/h. Clearly not enough. I’d need to peak at 70km/h, with an average at maybe 30-40km/h." Re the quoted text below:

1) do you need the resolution of each wheel revolution? what about dividing revolutions by 10? That’s a much smaller number to track, just multiply by 10 later to rehydrate.

2) for the sample rate instead of every minute can you store your average and when that changes log the new average with a timestamp? It’s more bits per sample but possibly way less samples overall. — -

“The EEPROM was the next issue. 512 bytes is a serious limitation. Some math was required to see if I what wanted to do was even possible. If I were to poll every minute over a ride I’d be able to record 8.5 hours of one byte readings. That’s pretty good, seeing a 200km ride would take approximately 6 hours.

One byte is capable of storing 256 possible values. Is that enough, or would I need more values? If my revolutions were 255 with a wheel circumference of 2110mm I’d be traveling an average speed of 32km/h. Clearly not enough. I’d need to peak at 70km/h, with an average at maybe 30-40km/h.”

]]> Comment on A Maker’s deep-dark secret by Troy http://www.eightlines.com/blog/2008/11/a-makers-deep-dark-secret/#comment-100 Troy Wed, 12 Nov 2008 20:17:21 +0000 http://www.eightlines.com/blog/?p=99#comment-100 That's an interesting epiphany Brent:) I remember building the traction kites with you and Jay and the argument was about cost mostly with Jay weighing by saying he could get a better quality finished product for a little bit more. For me the cost was immaterial, I was in it for the fun and experience. I subscribe to that mantra when making wine. A lot of people argue that making wine is cheaper than buying it. Unless they are particularly lucky (and good) they will find it hard to produce a home made bottle of wine that rivals a sub $9 Chilean import. I think we should all admit that we're in it for the fun, the experience, the learning, the bragging rights, the socialization but rarely to save money. Nice post :) That’s an interesting epiphany Brent:) I remember building the traction kites with you and Jay and the argument was about cost mostly with Jay weighing by saying he could get a better quality finished product for a little bit more. For me the cost was immaterial, I was in it for the fun and experience.

I subscribe to that mantra when making wine. A lot of people argue that making wine is cheaper than buying it. Unless they are particularly lucky (and good) they will find it hard to produce a home made bottle of wine that rivals a sub $9 Chilean import.

I think we should all admit that we’re in it for the fun, the experience, the learning, the bragging rights, the socialization but rarely to save money.

Nice post :)

]]> Comment on Conversation Clouds by Eightlines Creations › Conversation Clouds with Physics http://www.eightlines.com/blog/2008/11/conversation-clouds/#comment-97 Eightlines Creations › Conversation Clouds with Physics Mon, 03 Nov 2008 03:42:20 +0000 http://www.eightlines.com/blog/?p=82#comment-97 [...] after posting the previous entry I went to sleep, only to find myself thinking about improving the visual aspect of the Conversation [...] […] after posting the previous entry I went to sleep, only to find myself thinking about improving the visual aspect of the Conversation […]

]]> Comment on XBee Solenoid Controller by Brent http://www.eightlines.com/blog/2008/07/xbee-solenoid-controller/#comment-27 Brent Tue, 16 Sep 2008 01:22:00 +0000 http://www.eightlines.com/blog/?p=17#comment-27 Hi Lawrence, The minimum you can get away with on an XBee project is 2 XBee's ($30 each -- non-pro version), and 1 USB-TTL converter ($10). I also have an XBee-breakout board adapter ($6) that allows me to quickly swap out the XBee's when I need to program them. Add in a 3.3V regulator and power supply for the remote XBee. - http://arduino.cc/en/Main/MiniUSB - http://www.sparkfun.com/commerce/product_info.php?products_id=8276 This wasn't available when I got going, but it looks promising: - http://www.sparkfun.com/commerce/product_info.php?products_id=8687 An Arduino could substitute for the USB-TTL converted but you have to remove the ATMega168 IC to enable direct access to the TX/RX pins. You can also use the Wire.h library through Processing to bypass the IC removal, but I ended never trying it. The XBee has 8 digital I/O pins on board, and a couple PWMs (I don't recall off the top of my head exactly how many), the API mode allows you to configure them according to your needs. Hi Lawrence,

The minimum you can get away with on an XBee project is 2 XBee’s ($30 each — non-pro version), and 1 USB-TTL converter ($10). I also have an XBee-breakout board adapter ($6) that allows me to quickly swap out the XBee’s when I need to program them. Add in a 3.3V regulator and power supply for the remote XBee.

- http://arduino.cc/en/Main/MiniUSB
- http://www.sparkfun.com/commerce/product_info.php?products_id=8276

This wasn’t available when I got going, but it looks promising:
- http://www.sparkfun.com/commerce/product_info.php?products_id=8687

An Arduino could substitute for the USB-TTL converted but you have to remove the ATMega168 IC to enable direct access to the TX/RX pins. You can also use the Wire.h library through Processing to bypass the IC removal, but I ended never trying it.

The XBee has 8 digital I/O pins on board, and a couple PWMs (I don’t recall off the top of my head exactly how many), the API mode allows you to configure them according to your needs.

]]> Comment on XBee Solenoid Controller by Lawrence http://www.eightlines.com/blog/2008/07/xbee-solenoid-controller/#comment-26 Lawrence Mon, 15 Sep 2008 23:52:41 +0000 http://www.eightlines.com/blog/?p=17#comment-26 Hey Brent, I have seen what you did here with the XBee Modules and am impressed with your work. I myself am trying to use XBee to establish a two-way communcation system between an RF-scanner controlled by a microcontroller and the computer. I still have no idea which components I need to get the wireless portion working. Which parts do you recommend? We have a budget (it's a course project so we're looking at under 100 bucks) Thanks! Lawrence Hey Brent, I have seen what you did here with the XBee Modules and am impressed with your work. I myself am trying to use XBee to establish a two-way communcation system between an RF-scanner controlled by a microcontroller and the computer. I still have no idea which components I need to get the wireless portion working. Which parts do you recommend? We have a budget (it’s a course project so we’re looking at under 100 bucks)

Thanks! Lawrence

]]> Comment on Data Logger by Eightlines Creations › Data Logging to the Arduino EEPROM http://www.eightlines.com/blog/2008/08/data-logger/#comment-20 Eightlines Creations › Data Logging to the Arduino EEPROM Sun, 07 Sep 2008 18:14:36 +0000 http://www.eightlines.com/blog/?p=30#comment-20 [...] in the right position you wouldn’t pick up the digital I/O change. The solution, offered by Blalor, was to use the Arduino Interrupt commands. The Interrupt fires whenever a digital I/O signal is [...] […] in the right position you wouldn’t pick up the digital I/O change. The solution, offered by Blalor, was to use the Arduino Interrupt commands. The Interrupt fires whenever a digital I/O signal is […]

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