Jump to content


  • Content Count

  • Joined

  • Last visited

  • Days Won


Everything posted by username

  1. Hey all, My latest project features a G2553 in combination with a FTDI breakout board and a C++ GUI App written on the PC. Using these i'm able to control a AR drone sending Ethernet UDP commands from my PC. My next goal is to do all this at the embedded level and eliminate the need for the computer. Nevertheless, it was some great practice writing GUIs. Youtube Demo: Drone App Pic Will try to post alittle more info later if anyone has any interest. Thanks for looking! Nate
  2. This weekend i'll be releasing a GUI as an example of how to do this from the PC side. The micro side is super easy if using the G2553 as others mentioned and it would be the only way i'd go about it. Software bit banging is a pain.
  3. Nice wagnerlip! See, many different ways to do this. Its cool that you use the SSR, any chance have a part # for that or a price tag? Always wanted to try a SSR sometime. Interesting also that you used a thermistor, I didn't know they could be accurate over such large temp ranges. i'd be neat to test their accuracy versus a thermocouple. Will have to try it out. I'd be fun as a community project to see who can build the cheapest & quality oven. Might have to give thermistors a try and see how accurate they are. Looks like this one might just do the trick: http://search.digikey.com/us/en/product ... ND/1220081
  4. Well, there is still the max6675 which is 14.3 usd I think? Digikey has 5000 of them. Anyhow, the ad595 is 16 usd on digikey so i'm not sure there is value in that unless you can find it somewhere really cheap. There is also the AD8495ARMZ-ND which is a 5usd analog cold compensator. At this point, the AD8495ARMZ-ND device would probably be the best substitute if one isn't willing to pay for the max6675. However, a complete board redesign would be needed for that device. The reason I choose not to use it because it was not nearly as well documented or esteemed as the max6675. If it is to much to pay the extra 10usd for the max6675 you mine as well revamp the whole board and get rid of the lcd, multiple LSDs(replace with a single bjt),power jack, and headers. At that point you would be able to make it for decently cheap. Probably for about 12usd you could get a board+relay that could run a profile. 12+15+30 +5 = 62 usd. Or perhaps if you all go with the same oven, someone could take timing measurements and attempt to predict temp rise per how long the element is on. If you did that you may be able to eliminate the thermocouple and cold compensator all together but it would be more risky. However, all you would need then is a relay, micro, and a few other basic components. Or... you could try not using a cold compensator and attempt to do that with the msp430 that has a built in temperature sensor. lots of options out there. However, i'm slightly biased towards my features so i'd like to keep them . However, anyone of you are more then welcomed to attempt a cheaper board redesign.
  5. Hey Bluehash, Not sure if i'm missing something but according to my lookup on digikey there out of stock: http://oi41.tinypic.com/2rh4w11.jpg regarding the board itself, the raw cost we probably could get down to around 30 usd. (half of that being the cold compensator) so, 30 usd board + 30 usd oven + 15 usd thermocouple + 3 usd wallwart + 5 usd shipping = ~85 usd at 0 profit if you sweat some blood you probably could get the board price down to 25usd but i'd be quite difficult. Had a sales thread here but no one expressed interest once I was ready to build. Now those prices are not possible since the MAX6675 is the only SPI cold compensator available. viewtopic.php?f=22&t=2040
  6. Hey all, I'm honored by your interest. However, unless you guys are willing to pay the price I had in my sales thread I'm not sure your going to be able to build these ovens for any cheaper with a group order. Again, the 2 big spenders(besides the oven) are the cold compensator(15 usd MAX6675) and the K type thermocouple(requires small thermal mass + 400C peak 15 usd). Combined with all the other components on the board + relay + pcb that is around 45-50 usd. That price really isn't going to change much if we increase the order QTY to 5-10. We would need a cheaper source of thermocouples with a quick response and a high temp rating. I've looked but haven't found any yet. Also the MAX6675 is EOL which is why its so pricey. The replacement is the MAX31855KASA+ (has to be this part specifically for k type) but sadly those are now out of stock on mouser and they won't get any in till 7/1/12 =( . Even if we did get those it would have only reduced the price by 8usd. http://www.findchips.com/avail?part=MAX ... 1228906408 At the end of the day, your still looking at a 80 - 100 usd price tag with the oven. As long as your willing to pay around that price range then yea i'd be all in for it.
  7. I thought electromechanical relays were preferred for safety because they can be setup to fail open(Normally Open) while SSRs and SCRs can fail closed? I second that question. With a reflow oven that is temperature controlled, you can ensure to a decent degree that your components do not exceed a dangerous temperature range. For example, some components are "moisture sensitive" and thus easily damaged by overheating. However, plenty of people are able to get away with hot plate soldering so its up to the individual. I'm too paranoid rely on that method but its up to you. The profile itself is again to ensure the safety of the part as well as create good solder joints.
  8. I have a Rigol DS1052E, it was worth every penny of it! That would be likewise what I recommend. Prize per value it is by far the best and is easily hackible to 100Mhz should you so wish.
  9. Sorry for not fully understanding this, What types of SD cards can this be used with? Can it be used with any SD card? Also, for file types on the PC, say I want to store a data string of integers that would correspond to music that could be sent to a DAC, what type of windows file type would I use?
  10. Very impressive project! Would be awesome to implement something like this. Got a schematic as well?
  11. Very cool project =D 3D printed wheels? Where did you get access those? Going to have to add making a MSP430 robot to my project list... which is getting rather long.
  12. By all means! Hence why it is here! Glad it was of some use to somebody. Now as a few people may point out, this isn't the fastest and most efficient way to do UART but it is certainly enough to get by for most practical applications. Also happy to hear you got it to work on the launchpad. I have yet to try it on there yet because I refuse to spend another moment trying to get that thing to USB-->serial IC to work.
  13. What is wrong with using the silkscreen then to define your panels? Won't seed cut them for you in that case?
  14. w00t!!!! That place looks awesomeness! Thanks for the share!
  15. A simple well documented hardware uart "Hello World" example. Updated, thanks for member comments 3/13/13 Notes: This code is for launchpad rev 1.5 This is hardware UART, your launchpad jumpers must be set for hardware UART The TI TUSB3410 is a TERRIBLE usb-> UART chip and is very buggy on WIN7 64bit. If your still having issues, it could be a driver issue. Try on XP or use a different USB -> serial device. //Nate Zimmer UART example // Press button to print hello to terminal #include <msp430g2553.h> // System define for the micro that I am using #define RXD BIT1 //Check your launchpad rev to make sure this is the case. Set jumpers to hardware uart. #define TXD BIT2 // TXD with respect to what your sending to the computer. Sent data will appear on this line #define BUTTON BIT3 void UART_TX(char * tx_data); // Function Prototype for TX void main(void) { WDTCTL = WDTPW + WDTHOLD; // Stop Watch dog timer BCSCTL1 = CALBC1_1MHZ; // Set DCO to 1 MHz DCOCTL = CALDCO_1MHZ; P1DIR &=~BUTTON; // Ensure button is input (sets a 0 in P1DIR register at location BIT3) P1OUT |= BUTTON; // Enables pullup resistor on button P1REN |= BUTTON; P1SEL = RXD + TXD ; // Select TX and RX functionality for P1.1 & P1.2 P1SEL2 = RXD + TXD ; // UCA0CTL1 |= UCSSEL_2; // Have USCI use System Master Clock: AKA core clk 1MHz UCA0BR0 = 104; // 1MHz 9600, see user manual UCA0BR1 = 0; // UCA0MCTL = UCBRS0; // Modulation UCBRSx = 1 UCA0CTL1 &= ~UCSWRST; // Start USCI state machine while(1) // While 1 is equal to 1 (forever) { if(!((P1IN & BUTTON)==BUTTON)) // Was button pressed? { UART_TX("Hello World! \r\n"); // If yes, Transmit message & drink beer __delay_cycles(100000); //Debounce button so signal is not sent multiple times } } } void UART_TX(char * tx_data) // Define a function which accepts a character pointer to an array { unsigned int i=0; while(tx_data[i]) // Increment through array, look for null pointer (0) at end of string { while ((UCA0STAT & UCBUSY)); // Wait if line TX/RX module is busy with data UCA0TXBUF = tx_data[i]; // Send out element i of tx_data array on UART bus i++; // Increment variable for array address } }
  16. Yes that is correct. LSD(Low side driver) meaning a transistor between GND and load. A HSD (high side driver) would be a transistor between power and the load. As for usage of a mosfet, versus a BJT.... well you saw my flop in the IRC.... Ultimately, which to use depends on your application and as far as us hobbyists are concerned, it generally comes down to personal preference. The reason being you can commonly make either work. I personally prefer mosfets because they do not require a constant current to be applied at the gate in order to be turned on. Hook them up directly to the msp430 and not worry about current consumption. (provided i'm not pwming at a fast frequency) Regarding the protection diode, I take back what I said. As a rule of thumb it is probably best to have one in your circuit when dealing with inductive loads. Here is an excellent video regarding them:
  17. http://en.wikipedia.org/wiki/Relay Not sure theres not much to understand with a relay? A relay is simply a magnetically controlled switch. The magnetic control element is simply an inductor with a resistor in series. A relay generally has 4 input pins. 2 contacts should have ~ 10-100ohms of resistance between them. Use your multimeter to find these. This is the inductor that you use to control the switch. Apply whatever voltage is specified in the datasheet for the relay. The relay that I used with my oven was a "5V relay" and thus I applied 5Vs to it and used a simple LSD configuration as seen below with a mosftet. No protection diodes are really required because, provided your driving your relay correctly (aka not pumping a crapload of current through it) the inductive kickback shouldn't be enough to damage the fet. Another thing to note is that the relay is not polarized, a resistor in series with a inductor is not a polarized element so there is no positive or negative terminals. The other 2 contacts on your relay are you switch elements. They should go from infinite resistance to 0 resistance depending on the voltage you apply to the control element. Again, no polarization since its simply a switch. Simple representational diagram is below. Hope that helps! Sorry if your question was already answered.
  18. I was surprised myself. In any event, thanks to all for your consideration! And many thanks to SugarAddict for his generous donation! I'll be up for donating an assembled reflow oven kit for the next POTM that we have if anyone is interested
  19. Possibly, the next step would probably be to incorporate a SSR and a convection oven. Anyhow, another good step is to get a better MCU on there that has more coding space available to allow for more advance control. I redid the PCB to work with the MSP430G2553. =) Hardware SPI should also be able to be implemented with the MAX6675 or the newer cold compensator model. Hoping to ship these out and have a nice new control board kit ready to donate for the next POTM
  20. Thanks for the help SugarAddict, I saw that in the user manual also and wasn't quite sure what to make of it. However, I think i've figured it out now. What this statement means is that when using the internal reference AND using it "off chip" (1ma Buffer) or when SD16VMIDON = 1, you should apply a 100nF cap. The vref pin can't always be at 1.2V / Left Open when the ADC is functioning because an alternative function of the Vref pin is A1-. The pin can't be 1.2V and function as A1-. The fact that the A1- function exists on the pin eliminates the ideal that it is required for operation. Therefore it can be used as a GPIO during normal ADC operation if I'm not mistaken since the pin isn't required for operation. As for the A- pin, this can't be used as a GPIO because it is a required input of a ADC channel. However, it doesn't necessarily need to have an external connection to ground since it can be muxed internally to VSS. guess i'll see if all that is correct when I order the chip.
  21. I like "Love what you do, or leave." Gets old hearing about how much people hate their job.
  22. Hey all, Currently I am working on trying to use the msp430f2013 16bit adc. Finding the documentation rather lacking and had a few questions for anyone that had experience using it. Most of it is in regards to the basic pinout. Is it required that I use both the A+ and A- inputs of an ADC channel or is there any way I can get away with just using A+? I want the negative reference to be with respect to ground. So, if I have to use both the + and - inputs, is it then required that I connect A- input to ground? Is the use of the Vref pin required? Can I use the ADC and the Vref pin as a gpio at the same time?
  23. PCBs and Control boards are now for sale Will be shipping out on Mondays and Fridays based upon orders
  24. Hey dude, welcome to 43oh.com! :wave: Launchpad is a very cheap and good way to learn. Hope it helps ya! By the way, where you going to school? I'm currently at NDSU myself
  25. howdy all, coming up on a very very very busy semester so I won't have much of any time to build kits. I'll release the BOM to ya so you all can hopefully can make your own ovens and learn something. I'll also be selling PCBs for 4.25 usd eventually (hopefully not too much, shipping is expensive) . Gotta get back to the dorm though to grab them first. My circuit will accept 6-9V input guaranteed with a 270mA max draw with relay on. At 12V+ input will be pushing the 5V linear regulators and make them quite hot. The input jack is 2.5mm by 5.5mm Consequently I recommend something like this: http://www.ebay.com/itm/AC-100V-240V-DC ... 20c010e0a8
  • Create New...