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dubnet

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dubnet last won the day on March 26

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  1. It sounds like the RAID you are describing is RAID 0 which is non redundant striping, used to increase performance but has no redundancy/failure tolerance. Although single disk backups have simplicity, the risk you run is that drive can fail anytime (usually when you need it most ). It happened once when I was doing a customer workstation upgrade from XP to Win7. Copied the customer's data to a USB hard drive, did the OS install and then during the restore the disk started to fail. After much sweat and coaxing was able to get the restore finished but it was yet another reminder of the frailty of hard drives. RAID 1, 5 or 6 or even some of the RAID xx variants are, however, excellent backup platforms. For customer near line server backups we used 8, 12 and 16 drive SAS and high speed iSCSI based disk arrays, typically configured as RAID 6 with a hot spare. This allowed up to three drive failures before the array became critical (after the 4th drive failure your data is history). While this might sound like overkill in terms of redundancy, it addressed the problem of drives sourced from the same batch that tended to fail at the same time, or a drive failing during rebuild (happens with a weak drive due to the stress of the rebuild process). This gave us a little headroom to get drives replaced and put the array back to optimum status. With regard to controller failure, although I can't say that it never happens, in 20+ years I've had no controller failures but more drive failures (including enterprise drives) than I could even count.
  2. ...and a third monitor (or laptop/PC) for the logic analyzer watching the comms. I can truly relate as I had two laptops and a PC in play debugging comms not too long ago. It is somewhat interesting that we need a handful of computers to play with very inexpensive MCUs.
  3. @NurseBob For your video work where is the bottleneck? If it's the drive subsystem then perhaps an upgrade to SSD would be helpful. Perhaps not for the whole 21TB but maybe as scratch drives for the rendering process. Prices keep dropping and are now at the point, in my opinion at least, where the price difference between spinning drives and SSD is pretty easily justified by the performance gains. I have them in my laptops and main desktop and love the performance boost. In the past I have recommended adding memory, to a point (and you are north of the point with 24GB), as a way to inexpensively increase performance. Now, its a toss up between memory and SSD and I am leaning more toward the SSD and not solely due to lower prices. Reason is that even with less than optimal memory, the swap to virtual memory on the SSD is so much faster it mitigates the need for more system memory.
  4. A kindred spirit! Multi-level, multi-device backups, bravo! Btw, 100% agree on Macrium. It is a great product. It also makes drive upgrades, or switching from spinning drives to SSD, a breeze.
  5. Even at the highest speed (1Mbps) the spec calls out 40M max bus length. Good for stretch limos or buses I suppose. Here is a snippet from a CANBUS page ( http://www.interfacebus.com/CAN-Bus-Description-Vendors-Canbus-Protocol.html ): "A number of different data rates are defined, with 1Mbps (Bits per second) being the top end, and 10kbps the minimum rate. All modules must support 20kbps. Cable length depends on the data rate used. Normally all the devices in a system transfer uniform and fixed bit-rates. The maximum line length is 1Km, 40 meters at 1Mbps. Termination resistors are used at each end of the cable. The worst-case transmission time of an 8-byte frame with an 11-bit identifier is 134 bit times (that's 134 microseconds at the maximum baud rate of 1Mbits/sec)."
  6. Nice test. It would be interesting to see if running energy trace under CCS would yield a similar number.
  7. You could use one the A/D channels connected to VCC and then check that value periodically.
  8. In addition to what @NurseBob said you may also want to take a look at this: http://www.ti.com/product/cc2640?keyMatch=bluetooth&tisearch=Search-EN-Everything
  9. I forgot to mention that the MCU has an internal temp sensor that you could potentially use as part of your design. Mux resistance is listed at 1K (page 32 of the datasheet). If your source impedance gets too high then you run the risk of more noise. If you find your A/D results bouncing around significantly then you may need to drop from 100K to perhaps 50k or less.
  10. If you use the 2553 on your own PCB you will want to replicate the reset circuit (capacitor and resistor) that the Launchpad uses. Otherwise the MCU won't run. On the temperature sensor(s) I was envisioning using something like an LM34 or LM35 placed near the area in the PC enclosure you are interested in keeping cool. If this is done then when the PC is idling along the fans should run slower and when you are pushing it the fans will run at near maximum speeds. I would guess that you have some free four pin power plugs (with 5V) in the chassis. If you add a 3.3V linear regulator to your PCB to drop the 5V then it would resolve your power issue without splicing.
  11. First of all, welcome to the forum! In terms of pin usage you will want to pay attention to pins already used by the Launchpad (e.g.switches and LEDs) to avoid conflicts. With regard to the fan speed control, why not use temp sensor(s) in lieu of the potentiometers fed into the A./D converter? Perhaps just one, or possibly two, would be enough to adequately control the speed of all four fans. Just a thought....
  12. First of all, welcome to the forum! The product you are working with uses an 8052 as it's MCU. This forum primarily deals with the TI MSP43x, TM4C and some of the other general purpose TI MCUs. There may very well be people on the forum with some experience with this chip. However, to increase your odds of an answer you may want to post on the TI E2E forum as well. The following link goes directly to the forum for this product. https://e2e.ti.com/support/interface/usb/
  13. Depending on the length of wire between the master and slave you may need to decrease the pull-ups to about 4.7K or so. Also, your master is sending 4 characters and 1 byte continuously and your slave is looking for those in order. However, you have no synchronization to ensure that the slave is seeing the beginning of a transmission rather than something in the middle. For troubleshooting purposes you may want to simplify the data transmission to just bytes to eliminate that possibility. If you can borrow a logic analyzer (e.g. Saleae) that can go a long way in figuring out what is actually happening on the I2C bus. EDIT: You may also want to try sending some test messages in your code (unrelated to your I2C print routine) via serial.print to ensure that the problem isn't between the slave and the PC.
  14. You can post your code directly into your post by first selecting the "More Reply Options" button at the lower right hand corner of the post reply window. Then click on the icon represented by the less than / greater than symbols < > A window will then pop up that you can paste your code into. It will take care of the formatting (indenting, etc) so the code is readable.
  15. @@Neetee Some suggestions for you so that you can better be helped by the users on the forum: Provide the Launchpad you are using, as well as any Boosterpacks. Provide your code - it is difficult to understand what is happening without this. Explain what is working and what isn't working. And if something isn't working, what exactly is happening and what you have already tried in an attempt to get it working. If you are using any of your own circuits besides the basic Launchpad, please detail that with a schematic. If possible provide a photo of your setup. Sometimes issues have been spotted with this additional information. The upside for you is that you will get more useful information in a shorter time frame. EDIT: Apparently @@chicken posted while I was composing this post.