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greeeg

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Everything posted by greeeg

  1. greeeg
    It's cool that it is compatible with an off the shelf development kit, looks like you still need a weird cable/adapter, mini A (for the OTG) then micro B on the other end. Back in the day I remember alot of people using the 2.5mm serial jack within the older 83/84. My school didn't allow us to use any of the Nspire series because they had features we were supposed to learn how to do manually. I wonder if TI will create a 'lab' that school could use for introducing the students to programming. I actually own both an Nspire and the 89 now. I actually prefer the 89 over the nspir
  2. greeeg
    I'm not too familiar with the TMS320F28035, that seems to be a C2000 series. Looking at some of TI's dev boards it looks like their JTAG setup is all run by a FTDI (USB>parallel/IO) adapter. If cost is an issue you could take a launchpad, remove the optoisolators and tap out the JTAG signals onto your custom board. I would personally steer clear of buying anything with a FTDI IC from ebay/china given FTDI's stance on counterfiet chips, and bricking or not functioning with updates to their drivers.
  3. greeeg

    The Marquee Clock

    greeeg replied to zeke's topic in Projects

    Really cool demo @@zeke. Did you ever make progress sourcing a custom flex PCB? I know prototyping those can get expensive fast! Are you planning to tuck away the control PCB just behind the clock?
  4. greeeg
    Ohh cool, My smoothie board has been making the rounds through some of my machines. It's typically on either my custom openbuilds vslot based delta 3d printer (still very much a work in progress) Or my homemade reprap (the first thing I built with my purchased 3d printer) My CNC mill predates the smoothie board, it's running from a tinyG controller. Which seems to work quite well, I'm not sure if the onboard drivers struggle sometimes. I've occasionally either missed steps or the steppers have stalled, basically ruining the entire job. (I suspect this might be more of a mechanical issue th
  5. greeeg
    @@phenyl A small Chinese model. Typically refered to as CNC3020. I've bought a new spindle and control electronics. I occasionally have issues with the lead screws binding up, I think upgrading them is the next step on that side project. If you want a unit that was just going to work out of the box I wouldn't recommend getting this model.
  6. greeeg
    @@LIJsselstein The equipment is all mine and used as a hobby. I like learning new skills. I bought the CNC after reading Guerrilla guide to CNC machining, mold making, and resin casting I wanted to try it for myself. I'm always impressed with the results, but it does take longer to setup than say a 3d printer. Yes, the leakage could be from anywhere. I tested some boards before fitting the GPS/SD card and they measure the same 2uA. So I think it's all down to the MSP430 and passives now. I've heard some ceramic caps can have leakage into the 10-100nA range. Yes I've found that too, I
  7. greeeg
    Ran the enclosures through my Mill, made a little jig to aid in positioning. There are a few issues left to sort out. PCB is not retained downward in the enclosure, when removing USB the PCB lifts upwards. LEDs leak light between their corresponding holes in the enclosure Button needs a mechanism to reach up through the case. I plan to solve these issues by creating 2 custom parts. Part A: This part will wedge between the PCB and top of the enclosure. Have holes over the LEDs to create light pipes out of the enclosure. A channel around the button to house a switch cap, part B. Part
  8. greeeg
    @@phenyl hh, well if you've downloaded it to try then I guess you're right. So it doesn't look much like as "deal" more like an evaluation of half the package. I guess there are time when you need to make schematics without designing a PCB.
  9. greeeg
    @@phenyl Orcad is also a complete EDA package, Schematic+PCB
  10. greeeg
    Sleep current has been reduced down from 700uA to 2.5uA by changing some pins form pullup to pulldown when I disable the high side switches for the SD/GPS units. The 0.7mA was due to leakage current through their internal ESD/anti latchup diodes. 2uA is still high, the datasheet specs a LPM4 of >1uA. I might need to disable some modules or lower the core voltage. Maybe disable SVS? In more exciting news finally received some enclosures. This is basically what my local sales rep had on hand. Fit like a glove. Now I just need to get these into my cnc to do the cutouts
  11. greeeg
    Glad your first PCB worked!! (my first few boards never worked without a decent number of bodge wires.) Nice to see you got dug straight into Kicad. Here's a very useful tip, try switching the canvas to openGL or Cario. (Cario is slower). This will enable the new routing tools, including obstacle avoidance and push-shove routing. Hopefully you will find this useful
  12. greeeg
    The XDS110's contain a user UART channel that you could use. You can print out the received SPI byte and the transmitted byte. Having this on both ends should give you a good insight into what's happening. I agree with @Rei Vilo, A good logic analyzer is probably the best tool to debug digital communication level stuff. But it can be a large investment, especially just for a proof of concept.
  13. greeeg
    MAX7219's are interesting parts, however if I want to avoid the grey market. these parts are VERY expensive. digikey stock them at $14 AUD a piece. Also the displays I'm using are smaller 1.9mm leds, vs 3mm. and the SOIC package sadly would not fit
  14. greeeg
    Here is some information about how I'm doing my current measurement, and the results I'm currently getting. I'm using my uCurrent with my Agilent U1271A (these currents are all in the mA range currently, so the uCurent isn't strictly necessary.) I am measuring the current between the battery and my device, this will give the best battery life predictions. The device currently has 3 modes of operation: Sleep mode, Lowest power mode. This current should be lower, I think I'm getting some leakage through my high side switches. I'm going to instigate further. 700uA is still good, b
  15. greeeg
    Everything seems to run fine! No issues getting an initial fix, although because it's battery powered the MCU is always sleeping, and the code is interrupt driven. Needed one badge wire, for the MSP to detect battery charging status. Still no word from the local sale rep from OKW, He said it would be no problem getting 6 units, I'll get onto him this week. For now I'm still stuck with some 3d printed cases, that I can't use outside of development purposes. All the cutouts seem to align though. still need to add light pipes for the status LEDs You may have noticied my
  16. greeeg
    I took a look at your code @Lode, I think when you're copying QueueItems into your Queue, you should be copying the sizeof a QueueItem, not the sizeof QueueItem* memcpy(&q->items[q->count], i, sizeof(struct QueueItem)); Before your code was just copying 1 words from the QueueItem into the Queue. Because that's the sizeof a QueueItem pointer. This change worked for me on my G2335 Launchpad.
  17. greeeg
    Regardless of the value in the InterruptEnable (PxIE) register the InterruptFlag (PxIFG) register will be set when an edge transition matching the value in InterruptEdgeSelect (PxIES) register. If that bit is set when you re-enable the interrupt wont that trigger another P1 interrupt? To remove this occurrence you just need to re-clear the flag once the WDT timeout has occurred. That being said, you may still see an interrupt occur on switch release. // WDT Interrupt Service Routine used to de-bounce button press #pragma vector=WDT_VECTOR __interrupt void WDT_ISR(void) { IE1 &=
  18. greeeg
    I have actually heard about this while researching. I suspect that the GPS units are very susceptible to noise on the power rail. hence why physically separating it helps. my design powers the GPS unit direct from the battery rather than the local LDO. So hopefully any switching noise form the Micro is constrained to the LDO rail and wont leak back. I've worked on the code, updated the state machine that handles everything. It's all working on my bench, I'm yet to test the fix time. Current draw while "sleeping" is 700uA (only LPM3, I think I can knock off the timer I'm runni
  19. greeeg
    haha, I'm sure that ICs have become more resilient over the years. Glad to hear it's working for you. I mean if the caps were working, by all means you could leave them in. However it's probably not the best practice, ever transition essentially needs to charge or discharge all the energy in those capacitors if they're on the signal lines. This could become a significant power drain if running from batteries. But yes, decoupling capacitors (across power rails) are a very good thing.
  20. greeeg
    It doesn't sound right to me calling capacitors on signal lines "decoupling capacitors" sounds more like you've created an RC filter. With the R being the gate resistance of the driver behind the IO pin. What you're actually seeing is the effects of transmission line theory! Basically when a digital signal changes state very quickly (slew rate, or edge rate) it creates harmonics. On modern chips, even slow (by clock rate) micro controllers, that can span into the 100MHz range. This basically oscillates in your PCB tracks due to their inductance causing ringing on the edges due to reflectio
  21. greeeg
    I'm yet to code up the GPS stuff just yet, need to alter my test code to ensure I can actually enter a low power mode and shut off the SD/GPS stuff. But yes, unaided GPS will take 30-60 seconds to get a fix. These units are to be used outside so the reception should always be pretty good. That being said, my tests so far have been to "half" solder up one unit, and test the USB / MSC / SD side of things. I forgot to order the High side mosfet switches, so currently everything is always powered on. I bought it with a smoothie board from the hackaday store. Highly recommend, I use i
  22. greeeg
    Components and PCBs have arrived. Ofcourse I needed to assembled one to check it was all working. A few bodge wires to allow it to operate without the battery for now. Cutout fits the battery nicely It does all seem to work, I now need to work on the code to support the new LEDs and button, and to add a low power mode so I can connect the battery without the fear of it discharging completely.
  23. greeeg
    @sven222 It looks like you're trying to load a file into the flash area of a larger chip. The G2252 only has 2kB of FLASH, where as the G2452 has 8kB The device datasheet shows a table with this information. Even if your compiled program is less than 2kB, when it is compiled for the G2452 it will sit at the lowest flash address. I think the only way to solve this problem is to re-compile your code with the target set as msp430g2252, not msp430g2452. This should instruct the linker to place the code at an address where memory exists.
  24. greeeg
    It does depend on the sensors in question. Most that are designed for low power use via a digital interface will offer a low power mode, this might be enough for your application and will reduce the BOM. If they're analog sensors then your only option is to add some power switching circuitry to disconnect them from your system while not in use.
  25. greeeg
    Hasn't there been a handful of "high performance, cheaper than pi" SBC's? I don't like to get on the hype train, because it appears like almost none of them have stuck. If you actually require higher performance you usually have to pay a higher premium somewhere. Don't get me wrong, I'd love it to be true, but usually after the kickstarter these companies haven't got a solid plan in place for lining up distributors etc. and there's only ever one production run for the kickstarter.
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