Jump to content
43oh

mbeals

Members
  • Content Count

    347
  • Joined

  • Last visited

Reputation Activity

  1. Like
    mbeals got a reaction from OhmMegaman in Laser Controller   
    It is for a lab laser.  My research group uses digital inline holography to study clouds and turbulence in them.  The process involves shining an expanded, collimated laser beam across a test volume onto a CCD.  The diffraction pattern created by the particles in the volume is a form of hologram and is recorded by the cameras.  We can then take these holograms and numerically refocus it to virtually any position within the original sample volume, which reconstructs the original light field.  By iterating over the entire volume, we can see where particles come into focus and backout 3D position as well as size and shape.  
     
    Since the exposure time of even high speed cameras is too slow to give blur-free results, we use a laser with a ~1ns pulse length and actively trigger it in sync with the frame rate of the camera.  Since there is latency in the trigger line and in the response of the camera, we have to implement some sort of adjustable delay to the trigger line to keep everything in sync.  The laser itself is a stand alone actively q-switched DPSS laser, so outside of just monitoring diode current and temperature to make sure the laser's own internal regulation is doing its job, there isn't much control other than on/off and fire.  The main control is adjusting the triggering rate/dealy, (attempting to) keep it synced to an external reference, and allowing an external interlock system to kill the laser if needed.
     
    Anyway, my department recently won a grant to build a pi m^3 cloud simulation chamber, and one of the features is one of these holographic systems.  I decided since this was going to be a 'community' instrument, it needed a better control system than the 'mess of wires in a box with a 30 year old signal generator' system we have driving the smaller chamber we have in our lab.
  2. Like
    mbeals reacted to JWoodrell in reset pin   
    the reason for the capacitor and resistor on the reset pin is simple... I don't remember where I read it, but it makes sense.  it is there so that when the chip is powering up it is held in reset for some predetermined amount of time, the larger the RC circuit the longer it is held in reset while the power supplies stabilize.  then once its up, the resistor holds the reset pin high so it doesn't randomly reset like if it was floating. *edit* hehe roadrunner already posted this, i didn;t read the whole thread before posting */edit*
     
    you can have as large of a capacitor on the line as you want, as long as the programming input is isolated from the capacitance it doesn't care what is there.
     
    this is how I set up my stuff, and it seems to work well

  3. Like
    mbeals got a reaction from cubeberg in Ultrasonic sensor backpack   
    Don't feel bad...at least it's just the LEDs.  I just did the same thing, except I didn't have USB ground connected to the rest of the board.  Serial port came up and nothing else.
  4. Like
    mbeals reacted to oPossum in FTDI cycling?   
    D+ & D- are backwards on the mini USB B connector.
     
    C8 & C11 must be 47 pF.
  5. Like
    mbeals reacted to bluehash in Capacitive Touch PCB layout   
    Attaching eagle design files.
    Design Files.zip
  6. Like
    mbeals reacted to Fred in Capacitive Touch PCB layout   
    If you need a close up photo of the booster board then let me know.
  7. Like
    mbeals reacted to cubeberg in Capacitive Touch PCB layout   
    There's some good information here - including the files that B# just posted - http://www.ti.com/tool/430boost-sense1#technicaldocuments
  8. Like
    mbeals reacted to bluehash in Really Tiny DC fan   
    http://www.digikey.com/product-detail/en/UF385-100/259-1454-ND/1739059
     
     
    Via Reddit.
     
     
    Sunon Fans Mighty Mini fans and blowers allow product designers to meet the limited space requirements for heat dissipation or compulsive air convection designs. It offers the smallest (8mm), the thinnest (3mm) and the lowest energy consuming innovative design. Mighty Mini fans possess the advantages of exceptionally low noise and lowest power consumption. The patented sub centimeter breakthrough technology of these products is a unique innovation with their mature thermal technology having passed numerous reliability certifications.  
  9. Like
    mbeals got a reaction from lvagasi in Pogo Pins for testing & programming   
    Nice...speaking of programming with pogo pins.....I just ordered a set of boards yesterday that break out the .05" header on the side of the launchpad to an RJ12 to work with the PIC 6 pin ICD Tag connect cable:  http://www.tag-connect.com/TC2030-MCP.  If there's interest, I can post the eagle library for the footprint and the gerbs (if it's worth it...it's 5 traces on a .5" x .5" board).
  10. Like
    mbeals got a reaction from oPossum in Pogo Pins for testing & programming   
    Nice...speaking of programming with pogo pins.....I just ordered a set of boards yesterday that break out the .05" header on the side of the launchpad to an RJ12 to work with the PIC 6 pin ICD Tag connect cable:  http://www.tag-connect.com/TC2030-MCP.  If there's interest, I can post the eagle library for the footprint and the gerbs (if it's worth it...it's 5 traces on a .5" x .5" board).
  11. Like
    mbeals got a reaction from bluehash in Post your Thrift Store finds   
    Found this at a goodwill.  I was checking out and the lady in front of me was returning it because the screen was broken.  I asked the cashier what they were going to do with it and when she said they were going to pitch it, I offered her $5.
     
    I figured I might be able to scrounge a camera and possibly an LCD off it, but a few screws and two solder connections later I was greeted by a linux shell.
     
    I then contacted the company, sent them a picture of the broken screen and they sent to a brand new warranty replacement.
     
    The card slot is wired for NAND, SD and uart, so I should be able to build custom cards to do some pretty interesting things....if I ever find the time.

  12. Like
    mbeals got a reaction from xpg in Post your Thrift Store finds   
    Found this at a goodwill.  I was checking out and the lady in front of me was returning it because the screen was broken.  I asked the cashier what they were going to do with it and when she said they were going to pitch it, I offered her $5.
     
    I figured I might be able to scrounge a camera and possibly an LCD off it, but a few screws and two solder connections later I was greeted by a linux shell.
     
    I then contacted the company, sent them a picture of the broken screen and they sent to a brand new warranty replacement.
     
    The card slot is wired for NAND, SD and uart, so I should be able to build custom cards to do some pretty interesting things....if I ever find the time.

  13. Like
    mbeals got a reaction from cubeberg in Post your Thrift Store finds   
    Found this at a goodwill.  I was checking out and the lady in front of me was returning it because the screen was broken.  I asked the cashier what they were going to do with it and when she said they were going to pitch it, I offered her $5.
     
    I figured I might be able to scrounge a camera and possibly an LCD off it, but a few screws and two solder connections later I was greeted by a linux shell.
     
    I then contacted the company, sent them a picture of the broken screen and they sent to a brand new warranty replacement.
     
    The card slot is wired for NAND, SD and uart, so I should be able to build custom cards to do some pretty interesting things....if I ever find the time.

  14. Like
    mbeals got a reaction from cubeberg in Ultrasonic sensor backpack   
    It looks really nice.  This could wind up being a pretty cool little board.
     
    I was going to ask you if you hand soldered the QFN's, but it sounds like you reflow them?  Do you use an oven or hot air?
  15. Like
    mbeals reacted to GG430 in Decoding TI's pin packages   
    The just polished MSP430.com landing page has now the part number decoder too.
     
    http://www.ti.com/lsds/ti/microcontroller/16-bit_msp430/getting-started.page#pndecoder
  16. Like
    mbeals reacted to JWoodrell in .05" header part number   
    how many pin headers are you loking at,  I buy long ones then clip them apart to make the lengths I want...
     
    the listings look pretty good to me...
     
    50 point $4.32 (8.6 cents per point)
    12 point $1.27 (10.6 cents per point)
    6 point  $0.74 (12.3 cents per point)
     
    Search listing (through hole right angle, 1 row, 50 mil spacing, in stock) sorted by point count 
  17. Like
    mbeals got a reaction from spirilis in Water Jug Lamp   
    Well you already have a lens or sorts.  What makes a focused lens work is the fact different parts of the light wave travel different distances through the lens material, introducing the phase shift which focuses the light.  So to specifically focus the light, you would need to either alter the surface of the jug, use something like a fresnel lens or introduce something else in the water with a different index of refraction (and somehow control it).
     
    You probably could use something like solid acrylic rod in the jug to act as light pipe to get some neat effects.  The acrylic would be difficult to see in the water with the LED's off, but should give off a nice, translucent glow when illuminated.
  18. Like
    mbeals got a reaction from yyrkoon in Water Jug Lamp   
    Well you already have a lens or sorts.  What makes a focused lens work is the fact different parts of the light wave travel different distances through the lens material, introducing the phase shift which focuses the light.  So to specifically focus the light, you would need to either alter the surface of the jug, use something like a fresnel lens or introduce something else in the water with a different index of refraction (and somehow control it).
     
    You probably could use something like solid acrylic rod in the jug to act as light pipe to get some neat effects.  The acrylic would be difficult to see in the water with the LED's off, but should give off a nice, translucent glow when illuminated.
  19. Like
    mbeals got a reaction from chamakov in Bidirectional Communication   
    Yes indeed
     
    What you want is the Serial library.  If you look in the examples, there are multiple sample sketches that show how to set up serial communication.
     
    Half of the task will involve programming the launchpad to process incoming commands and transmit back something useful.  You can debug this step with just a simple terminal session.
     
    The second half of the task is interfacing to MATLAB, which will involve setting up a socket connection to the TTY port.  If you google 'matlab serial communication', you will find lots of sample code, as there are multiple ways to go about it, depending on what you need to do.
  20. Like
    mbeals reacted to LariSan in How to make ez430-Chronos-868 working on 915mhz?   
    I don't know of any easy way to do it, but I would think that you would have to pretty much re-design the board to change the frequency. 
     
    This is a really good app note on moving from frequency to frequency on the same antenna. This brings back a bit of nightmare flashbacks to my e-mag courses, but if you're into RF (or think you want to be) this may help : http://www.ti.com/lit/an/swra161b/swra161b.pdf 
    Where I found the above App Note
  21. Like
    mbeals got a reaction from GeekDoc in Laser Controller   
    It is for a lab laser.  My research group uses digital inline holography to study clouds and turbulence in them.  The process involves shining an expanded, collimated laser beam across a test volume onto a CCD.  The diffraction pattern created by the particles in the volume is a form of hologram and is recorded by the cameras.  We can then take these holograms and numerically refocus it to virtually any position within the original sample volume, which reconstructs the original light field.  By iterating over the entire volume, we can see where particles come into focus and backout 3D position as well as size and shape.  
     
    Since the exposure time of even high speed cameras is too slow to give blur-free results, we use a laser with a ~1ns pulse length and actively trigger it in sync with the frame rate of the camera.  Since there is latency in the trigger line and in the response of the camera, we have to implement some sort of adjustable delay to the trigger line to keep everything in sync.  The laser itself is a stand alone actively q-switched DPSS laser, so outside of just monitoring diode current and temperature to make sure the laser's own internal regulation is doing its job, there isn't much control other than on/off and fire.  The main control is adjusting the triggering rate/dealy, (attempting to) keep it synced to an external reference, and allowing an external interlock system to kill the laser if needed.
     
    Anyway, my department recently won a grant to build a pi m^3 cloud simulation chamber, and one of the features is one of these holographic systems.  I decided since this was going to be a 'community' instrument, it needed a better control system than the 'mess of wires in a box with a 30 year old signal generator' system we have driving the smaller chamber we have in our lab.
  22. Like
    mbeals reacted to VMM in Another 430 Watch   
    Hello.  I figured I would share a project I've been working on since I borrowed a lot of code from this forum.  It's a small watch using a g2553 and the same OLED display as "The Terminal".  Thanks bluehash for the breakout, RobG and gwdeveloper for code, and others.  

  23. Like
    mbeals got a reaction from Fred in Laser Controller   
    It is for a lab laser.  My research group uses digital inline holography to study clouds and turbulence in them.  The process involves shining an expanded, collimated laser beam across a test volume onto a CCD.  The diffraction pattern created by the particles in the volume is a form of hologram and is recorded by the cameras.  We can then take these holograms and numerically refocus it to virtually any position within the original sample volume, which reconstructs the original light field.  By iterating over the entire volume, we can see where particles come into focus and backout 3D position as well as size and shape.  
     
    Since the exposure time of even high speed cameras is too slow to give blur-free results, we use a laser with a ~1ns pulse length and actively trigger it in sync with the frame rate of the camera.  Since there is latency in the trigger line and in the response of the camera, we have to implement some sort of adjustable delay to the trigger line to keep everything in sync.  The laser itself is a stand alone actively q-switched DPSS laser, so outside of just monitoring diode current and temperature to make sure the laser's own internal regulation is doing its job, there isn't much control other than on/off and fire.  The main control is adjusting the triggering rate/dealy, (attempting to) keep it synced to an external reference, and allowing an external interlock system to kill the laser if needed.
     
    Anyway, my department recently won a grant to build a pi m^3 cloud simulation chamber, and one of the features is one of these holographic systems.  I decided since this was going to be a 'community' instrument, it needed a better control system than the 'mess of wires in a box with a 30 year old signal generator' system we have driving the smaller chamber we have in our lab.
  24. Like
    mbeals got a reaction from bluehash in Laser Controller   
    It is for a lab laser.  My research group uses digital inline holography to study clouds and turbulence in them.  The process involves shining an expanded, collimated laser beam across a test volume onto a CCD.  The diffraction pattern created by the particles in the volume is a form of hologram and is recorded by the cameras.  We can then take these holograms and numerically refocus it to virtually any position within the original sample volume, which reconstructs the original light field.  By iterating over the entire volume, we can see where particles come into focus and backout 3D position as well as size and shape.  
     
    Since the exposure time of even high speed cameras is too slow to give blur-free results, we use a laser with a ~1ns pulse length and actively trigger it in sync with the frame rate of the camera.  Since there is latency in the trigger line and in the response of the camera, we have to implement some sort of adjustable delay to the trigger line to keep everything in sync.  The laser itself is a stand alone actively q-switched DPSS laser, so outside of just monitoring diode current and temperature to make sure the laser's own internal regulation is doing its job, there isn't much control other than on/off and fire.  The main control is adjusting the triggering rate/dealy, (attempting to) keep it synced to an external reference, and allowing an external interlock system to kill the laser if needed.
     
    Anyway, my department recently won a grant to build a pi m^3 cloud simulation chamber, and one of the features is one of these holographic systems.  I decided since this was going to be a 'community' instrument, it needed a better control system than the 'mess of wires in a box with a 30 year old signal generator' system we have driving the smaller chamber we have in our lab.
  25. Like
    mbeals got a reaction from bluehash in Laser Controller   
    I'm finishing up the design of a project for school, and since it is MSP430 based, figured I would share it.
     
    The board is designed to be a controller for a DPSS laser.  The laser takes 5V power, 2 digital inputs (enable and trigger) and provides two analog voltage outputs (diode current and diode temperature).
     
    The controller is designed using the MSP430F5172 and has the following features:
     
    1. CLI control over either RS232 or BT serial port.
    2. External interlock to control laser enable line.  Interlock is monitored by MCU and can be bypassed
    3. Breakout for front panel control: 7 3V, debounced GPIO pins plus I2C bus.
    4. Header for HD44780 20x4 LCD connected to MCU via I2C port expander.
    5. Triggering can be performed by an internally generated signal or from an external source.
    6.  Expansion port to enable the addition of hardware pulse delay circuitry
    7.  External trigger output, with programmable phase delay from main laser trigger
    8.  All external connections (RS232, trigger, interlock) on independent (isolated) grounds to protect against ESD and provide ground loop isolation
     
    I chose the F5172 for it's 5V tolerant inputs but I'm hoping to be able to implement a sort of digital PLL using the TimerD perhip and its high resolution mode so that I can read an external trigger signal and output a phase delayed version to the laser.  We use this laser with a high speed holography system and typically trigger the laser with a TTL off of the cameras...but due to line latency need to tweak the timings to get them to line up.  I wasn't sure if I could hit the resolution I needed, so I added the expansion port to make it easy to upgrade the system.
     
    I still need to do a final design check on it and fix some resistor values, but plan on shipping it off to fab soon.
    pcb.brd
    pcb.sch


×
×
  • Create New...