MovieMaker
USA
Asked
— Edited
It was hard to get the compass installed because of the short length of wires. But, I finally did it. Now, the Compass works. But, when I change directions or if it is on for about 5 to 10 seconds , after giving me directions, it disconnects the wireless from the EZ board.
weird, do you think I need some pullup or down resistors? Is this what is happening. do you have these resistors built into the EZB or do we have to add them?
mel
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Are you powering the compass from +5v with port D0 try using the 3.3v (check EZ-B diagram) instead its just an idea from what you describe it doesn't sound like an I2C fault if it works for a few seconds. How frustrating
Later on today if I can find a couple of ferrite beads, I will put them on the signal lines.
It works GREAT for 5-10 secs.
:-(
D.J. What do you think??
I guess my only other option is to go with a resistor from +5 to each signal line. If that don't fix the problem, I am Shunked!
:-(
:-)
Can both be connected to the same I2C bus?
I want my Robot to keep itself leveled. But I get confused about wether to use a tilt sensor, a gyroscope or accelerometer, theres even 9 dof inertial measurment units that include both gyro and accelerometers. I would also like to give it a sense of direction and have thought about trying to connect a compass, but I only have so many ports. Some compasses have built in accelerometers for tilt compensation for the compass. So the sky is basically the limit for how complex and advanced I want it to be...heck It may even be possible to use a GPS system just to give it bearing on north or south etc. but its not like its going to travel the world or even go beyond my garage, and still I only have so many ports.
In theory I could use the I2C header to connect on there whatever and however many I want to connect to it but I have no experience with I2C. Im sure I can make the appropriate connections between the header and the various devices but how am I going to control it? Espescially when theres several different devices hooked up to it. I can get my hands on amazing little sensors and things but if I have no idea how to work with and translate the data and values of these devices, should I even go there? I can understand analog connections but I only have 4 available analog ports, the other 4 are taken by pressure sensors under the feet.
So I can hook up a basic 2 or 3 axis analog gyroscope on ADC to keep it leveled. I can probably figure out how to use the signals from an analog device and use that within ARC to control the servo's in some way. And maybe the Z axis of a Gyroscope can function as a means of giving it direction, isnt that possible? If not then I will need a compass. I do not want to use the Serial I/O ports because the few I have left are reserved for ultrasonic ping sensors. But with I2C Im guessing its not like I can just open up an ADC window within ARC to see a range of values as the data that comes out. I have no clue what kind of data to expect, how to read let alone control it, or even what to do with it.
umm, Im just trying to get a realistic idea of the options that I have. The question I suppose Im wondering about is to what level will using I2C devices require coding experience? Will I need to have a general understanding of VB or C+ coding languages?
..though Im still curious about the I2C connection. I really only need a Compass and accelerometer to keep it leveled and a sense of direction. I can get a single compass with 3 axis accelerometer that allows reading the raw data of all these components and would in theory be all I need to both purposes. the only thing standing in my way is a lack of understanding of how to work with I2C devices.
I want to keep it as minimal as possible and wont be adding much more, other then possibly the wireless camera. So if I can keep it leveled and a sense of direction with 1 device on the I2C header, that would be ideal.
Is it possible to control and read I2C devices with ARC? I can probaby find example code on this device in VB or something and use the VB scriptwindow in ARC and maybe go from there. But if I am facing thousands of lines of advanced coding just to manually be setting the right slave and master adresses, then Im not sure how far I want to go with that. If it is too complicated for me than maybe I should infact wait for the EZ-Bit and stick with using just analog and serial devices that are somewhat easily accesible through ARC.
The first EZ-Bit (compass module) is sent to the printers for our prototype. I should have that in a few days, then it'll be mass produced within a week if all tests are GO.
I'm surprised you needed pull-up for the module because the ez-b has pull-up's on the i2c interface already. plus, the compass module datasheet says it has pull-ups. That's a lot of pull-up's
I too am working on a sure I2C compass. I did everything you all have suggested and no more than 10 seconds of compass readings and then the Ez-B Bluetooth starts blinking and then the Ez-B white led turns from solid lit to blinking and the board disconnects and the ARC locks up. I think it's my Mini ITX. I don't think it has the possessor power it needs. It most likely the same issue why I can't run 2 web cams as well. I will keep you all posted on my progress.
First try shortening the wires. This thread will cove that if you read some of the posts I believe. If my memory works
Yeh I know and under stand from reading everybody's issues. My signal wires are 3/4" to 1" long with farite beads on them with 10k ohm pull up resistors from the I2C 5v to each of the signal wires. It might be an RF issue as well. My mini ITX ,the EZ-B, the wifi card, the compass module and the PC's bluetooth dongle are all on top of each other. I am going to try using my netbook to run the robot and see if that make a difference. My netbook has more power then the ITX I build for the robot thats onboard. I will let you all know on my findings. The easy thing to do now is to eliminate the onboard pc with an external one. I talked to you be for DJ about the dual web cam. My onboard ITX doesn't have the horsepower to run 2 web cams , but my netbook can. So my thinking is that it might the same for the the I2C compass module as well. Thanks again for all the help and DJ, your the greatest. Thank you
This update on my progress. I disconnected the robots onboard pc and connected it to my external netbook. No change. The ARC and the EZ-B run fine until I insert any of the I2C controls. As soon as I do, 10 seconds of reading and the ARC locks up, The EZ-B Bluetooth stars flashing and the EZ-B whit light goes out completely. Then I have to ctrl/alt-del to close ARC. Remove the power to the EZ-B and restart everything and the same thing happens. Now I saw a post to put the 10K ohm resistors from signals to ground. Tried that too with the same outcome. I have also got power and ground from another location on the EZ-B. No change. I guess today I am going to Radio Shack to find a PC board to mount the compass module. As of now, I am using a proto board. That might be what is giving me the effects of longer wires. Any ways I will keep you all posted.