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  1. jgauthier

    Detect ignition from OBD2?

    Wow, this was a long time ago. Here's how I would approach this problem now. There isn't a signal, or anything else that goes "on" when you turn on the ignition. However, what does happen is the CAN bus becomes active. I would use the +12V signal to power a small, low powered, MCPU...
  2. jgauthier

    Looking for a "camera controller" IC

    Oh yeah, I have found that thing. It's very cool, but I can't use it directly. However, if I could determine what IC they are using I could potentially use that, as it appears to be some kind of DCMI -> SPI conversion. Or some method to get multiple DCMI interfaces into an STM32 (multiplex...
  3. jgauthier

    Looking for a "camera controller" IC

    One of those painful things to me is finding an IC to serve a specific purpose. What I am trying to do: Connect DCMI/MIPI cameras, and "convert" that signal to USB Video Class. Then bundle those together with some kind of USB hub controller into an MCPU. I have a device that does something...
  4. jgauthier

    Determine Sampling

    Thanks for your responses. These are the challenges I am trying to solve exactly. So, I appreciate your advice. When I say "suddenly" I mean there will be an immediate 100G force applied to the object. My coworkers suggested using the first order filter system of Tr = 0.35/Fc. Thus getting...
  5. jgauthier

    Determine Sampling

    I have two scenarios, and I am trying to figure out appropriate sampling for these scenarios. First scenario is a piece of equipment with an accelerometer on it. The piece of equipment is going to be activated suddenly and travel at 20ft/s for 21ms. It will also stop suddenly. I want to capture...
  6. jgauthier

    MCPU suggestion

    I saw that same thread. I am going to give it a try. It was cheap enough. If that doesn't work I may try an STM32H7 series. I have a nucleo that I can try. They are quick little things, but not sure if they are good enough for this.
  7. jgauthier

    MCPU suggestion

    I haven't seen that one. Thanks for the recommendation. I am going to order a couple and see if they can pump 720p at 30FPS, which is my target resolution and frame rate.
  8. jgauthier

    MCPU suggestion

    Hello, I'm looking for an MCPU that can interface with a camera, and wireless. My objective is to grab the video data and send it over the wifi signal. One wifi device I am looking at is the 88W8801 which can be connected using a couple high speed interfaces (USB, SPI). Anyone have...
  9. jgauthier

    Selecting a MOSFET

    Thanks everyone. I believe my issues was an understanding that as Vgs was increased so was ID. And while that is true, I need to look at the characteristics graphs to determine a MOSFET will actually fit my needs. I appreciate it, everyone.
  10. jgauthier

    Selecting a MOSFET

    Hello, I am having some trouble selecting a MOSFET, and maybe I need more than one. The scenarios is a I have an MCPU that will be switching a GPIO at 3.3V. I originally wanted to switch a MOSFET to actuate a solenoid. The solenoid may be 12V, or it may be 24V. It's not completely decided...
  11. jgauthier

    Looking for a power supply recommendation

    Thanks for that! I will consider that option. I was running my board from a PC power supply, but when the motor kicks on, like you said, there is a slight voltage drop, and the board resets. I was trying to avoid that.
  12. jgauthier

    Looking for a power supply recommendation

    I am looking for a power supply that can provide a high discharge, on par with a LiPO type battery. LiPOs are typically used in quadrotors, and when the motors turn on, especially all 4, they are able to discharge a significant current to power them. Ideally, I'd like a table top DC power supply...
  13. jgauthier

    Noise from DC Power supply

    Nasif, Since I worked for a company that deals with cabling, I was able to talk to an engineering product manager who happened to have a device that eliminated ground loop noise. I put it inline with the power source, and it seemed to solve the problem. This was quite a while ago, so I'm...
  14. jgauthier

    Noise from DC Power supply

    I was able to power this from a pure DC 24v DC source, and there wasn't a buzz. I will explore the ground loop issues, which sounds intimidating.
  15. jgauthier

    Noise from DC Power supply

    Great idea. I will try a battery! I was doing some research on the ground loop theory this morning as well. I will read the links you sent.
  16. jgauthier

    Noise from DC Power supply

    Hello everyone, At my place of work I have a paging system. The paging system itself basically just accepts audio. So it's powered, and powers the speakers. We've switched phone systems, and the new interface requires a device in the middle that basically connects the phone system to...
  17. jgauthier

    calculate power factor

    This is going to sound like a pretty noob question, and to some degree it is. I'm building a power monitor, and using a current transducer. I read a similar project here:http://openenergymonitor.org/emon/node/58 I went through his code to learn how he calculate power factor, and it makes...
  18. jgauthier

    Building a power monitor

    I've solved the drift. My DC offset resistors were too high. The ADC wants little to no impedance on it's input. I read this can be solved by using an op-amp, but reducing the resistors in the voltage divider was enough that after constant readings, I experience 1/1000th of a volt drop. So...
  19. jgauthier

    Building a power monitor

    The drift is because the DC offset is dropping. It starts at 1.65V, and dips to 1.61V and stays there. But it happens in the first few full waves. This being caused by the capacitor, which is a 10uF. When I remove it, the DC offset drops instantly. The source voltage never waivers from 3.3...
  20. jgauthier

    Building a power monitor

    I didn't even notice that. I will run a much longer sample and see if the trend continues. I'm using a hair dryer to create load, and it seems to create some noise. But the drift... odd.
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