AS3935 lightning detector update

Posted on March 14, 2013 by Skye Sweeney

I was having problems with reliable communications with the lightning detector chip over the I2C bus. Sometimes I would read a register and it would not be at all what I was expecting. The situation was during calibration when I was reading register 8 and suddenly one of the control bits would get set to zero. Since I was only reading this register, having a bit change value was unexpected. And it was not just a read problem because the functionality of that was controlled by the bit changed as well. Continue reading →

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Super magnet

Posted on March 7, 2013 by Skye Sweeney

I just purchased a rather larger (1″ dia, 3/4″ thick) N52 super magnet to erase MiniDV video tapes. Wow! What an amazing thing. I can see why I had to agree to all the safety notices on the item. If you get your finger pinched by it, it would do some damage. Not finger severing, but it would certainly bring up a nice blood blister!

This thing is so strong you can hang a few pounds from it with only the contact with a wallboard screw! And yes, with a few swirls, a MiniDV tape is completely erased. For those interested, K&J magnetics is the place to go.

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Another excercise in Yak Shaving

Posted on March 3, 2013 by Skye Sweeney

I have been having problems with the I2C interface on a chip I have been playing with. Since I do not have an I2C bus analyzer (nor can I afford one!), I have been using my scope to decode bus transactions. That that gets old very quickly. So why not automate the process? Continue reading →

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DS1102D issues

Posted on February 24, 2013 by Skye Sweeney

I purchased a Rigol DS1102D 2 channel analog and 16 channel mixed signal scope a few years ago. For the most part I love the unit. It is small and portable allowing me to take it to the job site. But recently I have started to get annoyed by certain aspects of it. Continue reading →

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AS3935 details

Posted on February 10, 2013 by Skye Sweeney

After a very frustrating weekend, I am pretty confident I have the worst of the integration problems behind me. The Embedded Adventures board is a very nice board but did take the choice of SPI or I2C out of my hands. It was designed to be I2C only. Not a problem. The Arduino does I2C. Continue reading →

Posted in Arduino, AS3935, AVC, Components, Lightning detector, Pololu 9DOF IMU, Processors, Projects | 64 Comments

First impressions of the AS3935 lightning detector

Posted on February 4, 2013 by Skye Sweeney

After ordering the break out board from Embedded Adventures in the UK, I got a nice email indicating that they would ship to me via stock held in the USA. The email also included some sample code for a PIC. Continue reading →

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Temperature stabilization of the IMU

Posted on February 2, 2013 by Skye Sweeney

I have a Pololu 9DOF IMU that I plan to use for the Sparkfun AVC competition. One thing (of a few thousand!) that has me worried is the bias of the sensors as a function of temperature. The datasheet indicates a fairly strong effect from temperature. My first solution was to calibrate the sensors at various temperatures. But that would mean getting access to a thermal chamber. Now with the right permissions, I could have used the ones at work, but they are all big honking steel chambers. The one I am currently using is a 6 ton steel box.  Not a great environment for the magnetic compasses. Continue reading →

Posted in AVC, Pololu 9DOF IMU, Projects | 2 Comments

ADE7763 comments

Posted on January 31, 2013 by Skye Sweeney

I have received a bunch of comments on the ADE7763 home power monitor project. I will try to address then in the next few days with a special post.

Edit: I elected to reply to each with a unique comment.

Posted in ADE7763, Components, Home Energy Monitor, Projects | 1 Comment

Lightning Detector

Posted on January 31, 2013 by Skye Sweeney

First I must apologize for going off line so long. Back in June I got a cold that damaged my inner ear. With the damage, I have been suffering from vertigo. Luckily, the brain learns and re-calibrates the inner ear “gyro” and the issue slowly goes away. Just as that issue was disappearing, work picked up and I was working two shifts a day doing testing with a monster 3 axis rate table. But that seems to be going away and I have some time to myself.

First thing I did was to catch up on the Sparkfun forum where I discovered a post that “Embedded Adventures” had made a breakout board for the Franklin Lightning Detector chip made by an Austrian company. I immediately put one on order. Should arrive in a few days from the UK for $USA 27. Not too bad. This should prove much easier to design and implement than my custom circuit that was giving me such grief.

 

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Sandy and gyros

Posted on October 29, 2012 by Skye Sweeney

Seems like I spend more time logging non robotic events than the other way around. This weekend I was planning on spending quality time with a new ARM development board I purchased, but my wife and I decided that this would be the ideal time to paint our family/computer room. That meant packing up the file server, my development workhorse, and our general purpose computer. We got the walls prepared, and the ceiling painted, but failed to get the walls done. I decided that with the room gutted this was the time to install in wall Ethernet outlets and move the routers, switches, and modems to a basement closet.

I had hoped to do that work this week, but then came along Sandy. Sandy is this massive hurricane dumping buckets on rain on my house. Right now, I am just keeping out a weather eye and ready to respond if needed.

One thing I did stumble across this weekend (using my lab computer in the basement) was an issue with the Pololu 9DOF IMU. I was recording data every 4 milliseconds to an SD card from the various sensors. Issue one is that the magnetometer was not giving me full swing on the heading even though I had calibrated it a few days earlier. Need to look at that later. The more serious issue is that the gyro and the accelerometer were not updating values as fast as I was reading the device. A look at the datasheet indicates that the unit does have a max update rate that is defined by some registers. Need to look at the code to see how it was set up. But here is the catch; Those files are on my file server carefully boxed up waiting for the painting to be done. GRRR.

 

Posted in ARM, AVC, Personal, Processors, Projects | Comments Off on Sandy and gyros