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ak96

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  1. Sorry, forgot to mention I'm using the MSP430G2553. From what I understand from the first table, the input voltage cannot be greater than 0.3V higher than VCC and 0.3V less than VSS, and the second table gives voltage thresholds for rising or falling edges? The second table only gives information for 1.8V and 3V; is there any way I can find those threshold voltages for VCC = 3.7V?
  2. Assuming the MSP430 is powered by 3.3V, can I apply a 3.7V signal on a digital pin? Can I apply a 2.5V input? Will it still read rising and falling edges on the pin if the voltage on the pin is more or less than the supply voltage?
  3. I will go with programming using the launchpad. From what I understand, to do this I just need to connect TST/RST/GND/VCC from my pcb to the launchpad. Will this method only allow me to flash programs onto the chip, or will it also allow me to debug?
  4. I just realized that the op-amps I'm using have a minimum supply voltage of 3V, so 2xAA batteries will be cutting it close. I'm thinking of using a 3.7V lithium ion battery instead. Will the MSP430 be able to handle this voltage?
  5. I added some connections. Should I use another header to connect GND/TST/RST or should I add TST and RST to the power header. I'll take your advice on using 2 aa batteries over the 9 volt battery. I will need to adjust some of my resistor values in the heart rate circuit for 3V instead of 9V. Also, I thought the MSP430 only works with 3.3V. Will 3V be enough? Do you see any issues with my schematic? I left the pins I'm not using unconnected. Is there a better practice?
  6. I made a heart rate sensor, and prototyped it with the launchpad. The mcu reads BPM and displays it on an LCD. I now want to create a pcb without the launchpad. I've attached what I have so far. I'm powering everything from a 9V battery, so I have a 3.3V regulator which I will use to power the MSP430G2553. Can I just connect the the output of the regulator to the VCC pin, and connect all the other pins to the circuit as I did with the launchpad, or are there other considerations I need to account for? Also, how do I debug and edit the program while the microcontroller is on my custom pcb?
  7. ak96

    SPI doesn't seem to be working properly

    It's the MSP430G2553.
  8. I am using this code to communicate to the Nokia 5110 LCD display: https://gist.github.com/DmitryMyadzelets/83b6e1384a1ee35a7f5f Looking at the waveforms on an oscilloscope, I saw that there are only 2 to 3 clock cycles per write. For instance, the attached screenshot is when I write 0x44. The top waveform is the clock, the middle is chip select, and the bottom is MOSI. That doesn't seem correct at all. Shouldn't there be 8 clock cycles for transmitting 8 bits?
  9. ak96

    Need help understanding this code

    @@chicken I am new to programming micro controllers. I only started a couple of days ago. I'm kind of uncomfortable using that energia library because it feels like...cheating. The project i'm working on is a heartbeat sensor with a physical circuit and micro controller to count the beats. I want to make this project from scratch as a learning experience, and using a library that does all of the work for me defeats that purpose I think. Also, that is not my code. I found it on an instructable. So far, I've just learned how to blink LED's in different patterns at different speeds using interrupts and timers. What should I focus on learning to be able to make the heart rate monitor? Is there anything in particular I should look into?
  10. ak96

    MSP430G2553 ADC

    Neat project. Did you figure out the answer to your question?
  11. The code is for a heartbeat sensor using the MSP430. Which part is responsible for actually counting the pulses? lcd (1).h main.txt
  12. http://i.imgur.com/WYRodIC.jpg The black covering is on the bottom of the board rather than on the top covering the pins. I can't even set the board down properly because of it.
  13. When I plug it in and hit debug, i get an error that says : "MSP430: Error initializing emulator: No error". If I keep trying eventually it'll start working. Also, when I plug the MSP430 in, it immediately begins running the last program I put on it. Is this supposed to happen? How can I stop it from running any program? Another problem I keep having is that when I try debugging, for the P1 and P2 Ports, it says Error:unable to read. When I hit play it will say Error: unable to read, but when I pause it the error goes away. I am assuming this is due to a problem in my code?
  14. ak96

    Trying to alternate blinking of two LEDs

    @@cubeberg Yep, that's right. After I set all pins to 0 it started working. The bits are assigned random states every time I run it, and whenever the two LEDs start with the same state it works fine, but when they start with different states they blink synchronously. Thanks!
  15. Sometimes when I run this code, the LEDs will blink alternatingly, while other times they will blink synchronously. Why is that? #include <msp430.h> int main(void) { WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer P1DIR |= 0x01; // Set P1.0 to output direction P1DIR |= 0x40; for(;; ) { volatile unsigned int i; // volatile to prevent optimization P1OUT ^= 0x01; // Toggle P1.0 using exclusive-OR for(i=0;i<10000;i++){} // SW Delay P1OUT ^= 0x40; } return 0; }
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