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cde

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Everything posted by cde

  1. Why are you adverse from using a pulsed load resistor? Depending on the power bank, the pulse only needs to be once every 15 seconds. The average load will be in the <1 mA range.
  2. I'm not sure they will think much about it. Electronics suppliers and shipping costs go hand in hand. They don't figure the shipping until everything is packed, much after you ordered. Digikey, Mouser and even TI (who IIRC uses Digikey) as prime examples. 9 bucks for a 2 pound package is about normal.
  3. Yeah, VIH levels are tricky. The AVR Mega line is supposed to accept VCC * 0.6 as input high, but that's the minimum. So 3 at 5V. But if your at 5.1V and the input is at 2.9V...
  4. Well, it does have the COM pin, which is typically tied to VCC/Vsup when you drive an inductive load/motor. It's the common pin for the built in flyback diodes. But the ULN2003 doesn't have active logic that needs its own supply.
  5. Mifare classic hasn't been compatible with most galaxy phones from the S4 generation and up. Mifare classic is basically broken out the box by NXP, and since they don't license out, all the phones with broadcom NFC radios can't access them.
  6. I don't think mDNS is what OP wants. More like Dynamic DNS.
  7. Just local? From a single PC, use a host file. This requires a static ip on the device. For a network, try checking your router's configuration. It can either map single static IPs to a hostname, or allow mapping a mac address to a hostname. Or allows mapping a mac to a specific DHCP lease, which can then be mapped to a hostname. From the device, edit the code so that it registers a hostname with the DHCP server. A bit more complex.
  8. And keep in mind to try previous TI coupon codes too. Sometimes they forget to disable them.
  9. cde

    OV7670 and MSP430

    If you are using i2c, and have properly coded the i2c open-collector (output ground and high-z input, never output high), you don't really need the 2231 as a level translator. But this really seems like a coding issue. we can't help without your code.
  10. A small project. G2211 PIR Sensor 5630 LED strips On/Off button Button Doubles as Test Mode Board half way done. Using a Reg104 DPAK (I'll stick to a TO-220 next time) as the regulator, and MMBT3904 sot-23 transistors on a board of my own design. The base resistors should be on the back, but I didn't have the right value 0805/1206 resistors at the time. Quite proud of my clean, flush mount, perfect fit for the button, led, and sensor. Two tricks. One, I used two pins to provide high to low, and low to high interrupts, instead of swapping the interrupt in code, since I won't always know it's state. It is much simpler like this for me. Two, the status led is only 0.66 mA. 600 microamps. Look how visible it is. Keep that in mind when building your own projects. One issue. I have the PIR sensor directly powered by the 3.2V regulator I am using, bypassing the HT7133 on it. As such the PIR sensor triggers when the leds turn off, likely due to noise/ripple experienced. Next time I'll just power the sensor from the 12V with it's regulator, or I could change the sensor to non-retriggerable mode, or wire the enable pin to the msp430. I just coded a delay that ignores the trigger. The timing of the lights is long enough that it shouldn't be an issue in normal use. main.c common.h
  11. Does it? g2211. Or any of the basic valueline launchpad ones
  12. I always use the calibrated 1 MHz DCO as the main code clock. This sets the SMCLK to the DCO. BSCTL1 = CALBC1_1MHZ; DCOCTL = CALDCO_1MHZ; I currently use the Watchdog in timer mode, set to SMCLK divided by 32. This gives me 32 interrupts per second (1 Mhz / 32 = 31.25 kHz). WDTCTL = WDT_MDLY_32; Problem is that this when I am using the Watchdog on the SMCLK, I can't go lower than LPM0 (SMCLK + DCO), which is a power hog compared to LPM3 (ACLK on). I also don't want to use the external crystal. So, how can I use the Watchdog timer on the VLO/ACLK, while keeping the main on the calibrated MCLK/SMCLK/DCO?
  13. A timer based delay will not work like you are expecting. First, every 49 times the code loops, you run Delay(). Which resets the timer (TA1CTL = TACLR). So the interrupt never happens. Second, You don't do anything in the interrupt. You don't clear the flag. You don't run any code. Third, your expecting it to block your main code. It won't. It runs in the background, allowing your code to continue. That's why you see most Timer based delays using LPM. LPM stops the main code until the timer interrupt happens, and then starts running the code again. If you want something to work like that, you need a blocking delay (Like running a large "for" loop), or LPM, or using the interrupt to run the code.
  14. Nice. Of course, the launchpads run at 3.5V, and have USB/5V available, which in my experience is enough to power the lcd, with logic at 3.5V talking just fine with them. But that's kludgy so nice write up.
  15. Today, while trying to create a motion sensing Pantry light, using a HC-SR505 mini PIR sensor, was the overly sensitive sensor. I was trying to power it directly from the Launchpad's 3.5V line, but it kept retriggering and retriggering for no reason! It has a beefy 22
  16. Applies to FedEx Ground, UPS Ground, USPS First Class Mail and FedEx International Economy only. I wonder what the Customs fee would be though. Some info says Fedex Int Economy has no brokerage fee.
  17. Found a nice app note by TI, and wrote some thoughts on it: Just recently read an app note that targets your same circumstances. Using power solutions to extend battery life in MSP430 applications By TI's Michael Day. While it uses the MSP430 as its target, the same applies to any MCU. Depending on the MCU's Current vs Voltage, and Voltage vs Clock Speed, using an LDO with a low Quiescent Current will be much better than powering the MCU directly off the battery. The example uses 2x AA, and a TPS780xx regulator with 0.5
  18. cde

    Ultra Low Power

    The MSP430x2xx family guide suggests: Don't leave any floating input pins, don't leave them in a peripheral mode if you don't need them. They need to be set to a known state (Output low, Output high, or input with pullup/down). If they are connected to something, like an led, obviously if you want the led On, output high, otherwise output low (or Vis-versa if the led is tied to V+) to minimize that current draw. Ideally, any input pin should be set with the pull resistor that matches the normal state of the input, to reduce the draw through the pull-resistor. Even then, with the typical pull resistor value of 47k?, that's a 0.07 milliamp draw. 70 Microamps. See section 2.3-2.5 of the family guide http://www.ti.com/lit/ug/slau144j/slau144j.pdf
  19. The only way to protect it from being stolen is by not sharing it. The next best is sharing only compiled binaries/hex, maybe. Aside from that, it's hard to protect something, because you'd also have to figure out that they stole it in the first place. Unless it's so super unique, and you constantly monitor for it, you won't know. And if you did, you'd have to prove they stole it. Then the legal process, etc. For a hobbyist, it's near impossible.
  20. High res picture of your PCB, Both sides.
  21. cde

    protoboard

    That protoboard was designed with the 430 launchpad in mind. It would only access J1 and J2, the original launchpad headers. If you look closely, you will see that the headers on it are offset. The assembly manual has a better picture. http://store.43oh.com/image/data/LPB_ProtoKit/LPB-ProtoKit_v1.0.pdf Instead of using a pass through or extra long header pins, it offsets the headers to one side, and joins them together. It may look like it has access to all four headers, but does not. That said, you could easily modify it for the 40 pin headers, by cutting the trace between the two sides, and using 4 sets of Stacking Headers. You'd also have to cut the 3.3V trace so that it wouldn't be tied to the 5V on J3. If you want it on the top, the stacking headers have to go female side down, meaning you'll have male pins on your side.
  22. Well if you go with i2c displays, you might as well use a i2c port expander or led driver for the Light Tree. Simpler than multiplexing or anything.
  23. You seem to have the general idea down. You could try adapting any number of arduino based Derby timers, like http://www.miscjunk.org/mj/pg_pdt.html with Energia, or start from scratch. You could easily use two msp430 chips if its too big for one. Like, off load the gate and drag race light tree to one msp430, and then do all the time keeping and displaying on another. Like Press Button on 430 A, A Lights tree, A drops gate, A toggles gpio of B, B starts timing, reads race times, displays on LCD or LED Matrix or sends via UART to computer or bluetooth.
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