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Psii

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  1. Yeah that seems like the cause. 220nF didn't work either. Used 2x100nF labeled caps with high tolerance in parallel. Measured their total capacitance to 178nF
  2. I am sorry for being such a pain. I did try a 2.2nF numerous of times without success. Your last post made me realize the purpose of the capacitor. Since my pullup resistor deviates from the recommended value, I figured I had to use another capacitor to get the appropriate charge time. I tried lots of different values. What finally made it work was 178 nF, holding the device in a reset state for just the right amount of time. The device now operates as intended. Thanks for all your help
  3. Scratch that, I am at a loss here. The above configuration worked yesterday. I think the device is set up to be able to run in standalone. I can get it work doing the following: Power the device. Then short RST to ground for a split second, reseting the device. Works everytime. Any suggestion? Is there a register I can set in order to generate the same condition as when grounding and then releasing the RST line?
  4. Got it working by adding a voltage regulator as a power supply, 100R pullup and 2n2F pulldown on RST, 100R pulldown on TEST.
  5. Oh, the configuration on the TEST line also seems to matter. If it is not connected during a power cycle, the ADC gives the wrong value.
  6. Leaving TEST open or connecting it to ground did not change anything. The system still works while RST is connected to the ez430. I then tried to connect a 47k between RST and Vcc, and it stopped working. 2n2 F to ground did no good either. Tried lower resistors without luck. When connecting RST directly to Vcc, the circuit operates but gives the wrong ADC value. There is a 4.7k pullup to Vcc on the PCB, god knows why. I just know I cannot do anything about that, and it is not sufficient for standalone operation. So I guess I have to emulate the exact component configuration on the RST lin
  7. Hmmm, as far as I can see, there is a 4,7k ohm resistor between RST (4701 SMD) on the PCB. And TEST is not connected to anything. I disconnected TEST and connected it to VCC, still worked. But when I tried to connect REST to 47k, it stopped working
  8. OK, so I have encountered a problem. The circuit programs just fine and works... as long as the programming wires (two wires) are connected too the device. Once I remove them, the interrupt routine for SPI will not trigger. When I attatch them, it works again. I also noticed that if I turn the LED on, then unplug the SBW cables, the LED light will become weaker. Does this mean the MSP430 does not get enough current?
  9. I guess it could be, because the data seems very unpredictable. On the other hand, the SPI clock is set to 16 MHz/128 = 125 kHz, so I don't think that could be the case. (2 hours later) I got it to work. The thing is that I am switching between using I2C and SPI on the same lines. The iniatilization of these interconnection standards were wrong. I went with using hexadecimal values instead of the library names when setting the USI registers, and it worked: void SPI_slaveInit(void) { // SPI USICTL0 = 0xE3; USICTL1 = 0x11; USICKCTL = 0x00; } void i2c_masterInit() { // I2C
  10. I am using my MSP430F2012 as a slave to an Arduino. The arduino sends out the value 0x01 whenever I press "1" on the keyboard. So basically, what I want to do is have the MSP430 execute different operations depending on which value it receives from the master. In debug, mode I put a breakpoint in the cases where the value I read from USISRL is 0x01 and 0x02. The variable RxData (unsigned char) stores this value. The switch statement tests this variable and executes the appropriate operation. The problem is: Every second time I (odd numbers it seems) I press "1", RxData reads "2", although
  11. By this you mean that the chip select is controlled by the slave?
  12. Fixed it using some transistors to make the voltage converters.
  13. I think I have found the cause. It was not the Arduino but the voltage dividers I had used to drive the logic level from the Arduino from 5 V to 3 V. I changed the SDA line voltage divider with a 3.3 Zener diode to ground, and now I get the correct pulses, but about half the amplitude that should be expected. Here is a capture:
  14. This is when disconnected from the Arduino: This is when I connect SDA to the Arduino:
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