SimpleIDE Terminal won't display test message

I've set up a Propeller DIP40 on a breadboard, along with an ft232rl circuit based on the Prop Plug for communication. I've connected 100nF bypass capacitors on all VCC sources, as well as 10uF caps on the source regulator. There is also an EEPROM for storing the program, along with a 20pF, 5MHz crystal oscillator as an external clock.

Everything seems to be working fine; the Propeller is successfully detected by Propeller Tool and I can upload programs compiled using both it and SimpleIDE. When I upload the downloadable blinking light Spin program using Propeller Tool, the light blinks as expected, so I don't believe there is an issue with the crystal or the Propeller. However, when I attempt to run the SimpleIDE test program which displays "Hello!!!" in the terminal, nothing will display. I've even tried adding a pause of 2 seconds to wait for the terminal display to load, as well as compiling and running other terminal I/O programs, with no success.

So far, I've tried changing the board type to Generic and changing the baud rate, but those don't work either. For some reason the terminal doesn't seem to respond to anything. I'm using Windows 10, if that changes anything.

Comments

  • 10 Comments sorted by Date Added Votes
  • Are you making the appropriate clock setting statements in your program?

    I assume you're using C? Sorry but I don't know which clock statements are required for a C program but now that I type this, I imagine SimpleIDE likely adds these statements for you.

    Where are the 20pF caps used? I know some microcontrollers require the crystals be used with accompanying caps. The Propeller does not use caps with the crystal.

    I'd also suggest placing your "Hello!!!" statement inside a loop so you can be sure you don't miss it. Two seconds is kind of cutting it close. I know I've often missed seeing a message with just a two second delay.
  • I tried making the appropriate clock setting statements in Spin, but not in C. Apparently, in SimpleIDE the correct statements are automatically added by the compiler for the default PLL16 and 5MHz configuration, so you're right about that. I'm fairly new to this microcontroller, so I'm learning all of this on the fly.

    I noticed after reading further that the LED Spin program didn't have any clock statements, so it was probably just using the default internal oscillator. After adding the clock statements and using that clock as a source, the light stopped flashing. I'm going to have to check the external oscillator using a x10 probe tomorrow, with the correct clock statements, and see if it's oscillating at all. I didn't add any extra 20pF caps to the crystal; the crystal itself is rated with a 20pF capacitance.

    I tried putting the "Hello!!!" statement inside an infinite while loop, but no luck. I was reading in another forum that the external oscillator circuit within the Propeller is easy to damage; since I received this IC from someone else, I hope that's not the case :(
  • cameo23456 wrote: »
    Everything seems to be working fine; the Propeller is successfully detected by Propeller Tool and I can upload programs compiled using both it and SimpleIDE. When I upload the downloadable blinking light Spin program using Propeller Tool, the light blinks as expected, so I don't believe there is an issue with the crystal or the Propeller. However, when I attempt to run the SimpleIDE test program which displays "Hello!!!" in the terminal, nothing will display. I've even tried adding a pause of 2 seconds to wait for the terminal display to load, as well as compiling and running other terminal I/O programs, with no success.

    Where you uploaded the program, to RAM or to EEPROM ? If to RAM, it is possible that the terminal window toggles the DTR line causing a reset erasing whatever is in the RAM. Try to upload to EEPROM, it should work, unless there is something else (checked the pin numbers and speed for the serial port ?).
  • Duane DegnDuane Degn Posts: 10,001
    edited January 23 Vote Up0Vote Down
    cameo23456 wrote: »
    I noticed after reading further that the LED Spin program didn't have any clock statements, so it was probably just using the default internal oscillator. After adding the clock statements and using that clock as a source, the light stopped flashing.

    It sounds like the PLL circuit if blown. I've done this myself several times.

    Without the PLL it's pretty hard to get serial communication to work. I think there are ways to auto detect the baud which would allow a Propeller board to use serial without having an accurate clock but I haven't tried this myself.

  • So... I just checked the external crystal oscillation with a 10:1 scope probe and it seems to be working fine at 5MHz. The output appears as a sine wave instead of square, but I think this is because the scope is filtering higher frequencies. Is there anything else software-wise that I could be missing?
  • Or, from what you're saying, is it possible for the crystal to be oscillating but the PLL not work at the same time?
  • The PLL can be damaged by not having the proper capacitors at VCC and VSS. This usually happens when people leave them out of the circuit. I believe the xtal will oscillate, but because the PLL is blown, can not be used to provide correct frequencies.

    Infernal Machine
  • Ah, got it. I've ordered a new Propeller to see if that's the issue; I'll provide an update once I try it out.

    Thanks for the support!
  • Hi all,

    I tested the new IC yesterday and the issue was definitely the PLL. I didn't realize the XI/XO and PLL could operate independent of each other.

    The old IC is still usable, if I don't need the multiplier :p

    Thanks again
  • cameo23456 wrote: »
    Hi all,

    I tested the new IC yesterday and the issue was definitely the PLL. I didn't realize the XI/XO and PLL could operate independent of each other.

    The old IC is still usable, if I don't need the multiplier :p

    Thanks again

    Good deal! Remember those capacitors! :)


    Infernal Machine
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