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new prop stops at 86% - Page 2 — Parallax Forums

new prop stops at 86%

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  • There is a simple solution to my problem... change to raspberry and arduino.
    I have 2 propeller chips not working and a simpleIDE that cannot print to Terminal.
    I have reset the computer, changed to 3 different OS (7, 8.1, 10), wasted 3 days and there is no solution.
    I bought NEW crystal, NEW eeprom and the result is zero!

    Thus if someone has an old version of simpleIDE please make a dropbox file and upload it.
  • Not to mention that the drivers cannot find the UART. Mercy please!
  • Heater.Heater. Posts: 21,230
    Loopy,
    The fact that a crystal MUST be used for programing the Propeller or the EEPROM
    This is not correct.

    From reset the Propeller runs from it's own internal RC clock. The download/programming protocol is robust enough to tolerate any variance in that RC clock frequency. It's designed that way.

    Even if you do have a crystal attached it is not used until your program is loaded and you have specified your clock source to do so.

    Certainly my first Prop was a DIP welded to a strip board, with nothing but voltage regulator and associated Rs and Cs, and decoupling capacitors. It was programmed via USB/RS232 adapter and the transistor Prop programming circuit. Or via a Prop Plug.




  • Dave HeinDave Hein Posts: 6,347
    edited 2015-12-08 12:36
    johnprokio, your problems could have been fixed in a few minutes if you would have answered all of our questions. You have not provided a schematic or picture of your circuit. You have not told us definitively whether you are using a crystal or not. You have not answered questions about the amount and type of capacitors you have placed at the power pins of the Prop and other components. AFAIK nobody else is having the same problems you are.

    As far as I can tell you do not need an old version of SimpleIDE to solve your problems. Others have run SimpleIDE on Windows 7 and 8 without any problems, and I suspect people run it under Windows 10 as well. You have said that the Prop doesn't even work with the Prop Tool. We've told you that you need a crystal for serial to work reliably. Have you done that, and does it work now?

    Answer all all of the questions and provide us a schematic or even a picture of your circuit and we can fix your problems in minutes.
  • I managed to make one chip print using 115000 baud rate.
    And also managed to make the other light a led.

    Dave I am using the schematic that the propeller has in education 40 dip kit.
    I am using 6.3v 1000mF, I have tried both with and without crystal, with and without eeprom.
    I couldn't upload any photos because the computer is on OS changing.
  • Heater.Heater. Posts: 21,230
    edited 2015-12-08 13:17
    OK, looks good.

    Only I don't see any decoupling capacitors near the Prop power and ground pins. Others here can probably suggest suitable values/types better than me.

    Is that a red LED driven from a pin with no current limiting resistor ?!

    Do your bread boards have continuous runs for the power and ground buses? I notice you have red and orange jumpers linking parts of the power bus but nothing in similar positions on the ground bus.
  • I have just plugged it there to see if the code runs. Don't worry I put resistors
  • what will happen if I plug a crystal of higher MHz? in the propeller education kit it has a 5MHz what will happen if I plug an 8MHz or even a lower, 3MHz?
  • Dave HeinDave Hein Posts: 6,347
    edited 2015-12-08 14:05
    johnproko, thanks for posting the pictures. Your breadboard looks almost identical to mine that I build from the PEK. I've never had decoupling capacitors on it either, though it is a good idea to add them. The main differences between your setup and mine is that I use a 9V battery, and I only have one Prop on the board.

    I am still a little suspicious of using 4 AA batteries to power this circuit. The 6 volts is right at the minimum voltage for the 5V regulator, and a second Prop + EEPROM adds to the current draw. Could you try disconnecting the power to the second Prop and see if that works? Or could you try using a 9V battery or a 7.5V wallwort to see if that makes a difference?

    Oh, and Heater is correct that you weren't using a resistor on the red LED. This could damage the Prop. When you say you "put resistors" I assume you mean you added a resistor after you took the photo. The picture clearly shows the red LED lit without a resistor.
  • Heater.Heater. Posts: 21,230
    I might try a lower frequency XTAL, like 3MHz. Going up in frequency on a breadboard is probably fraught with problems. (Of course I would try it as well if I had the parts to hand. I have Propellers here, on proper circuit boards with 6.5536Mhz crystals, resulting on the Props running at 104MHz.

    Don't forget to change the clock settings in your code.

    Talking of crystals you could probably do with some caps from the crystal pins to ground. Again others here can advice on values for that etter than me.

    https://blog.adafruit.com/2012/01/24/choosing-the-right-crystal-and-caps-for-your-design/

  • Dave HeinDave Hein Posts: 6,347
    edited 2015-12-08 14:10
    Heater. wrote: »
    Do your bread boards have continuous runs for the power and ground buses? I notice you have red and orange jumpers linking parts of the power bus but nothing in similar positions on the ground bus.
    Heater, the breadboards have a solid black line along one bus, and a broken red line along the other one. This indicates that the black bus is connected all the way through, and the red one is separated in the middle.

  • The lack of decoupling capacitors is the first thing to fix - no logic chip is ever expected
    to function without proper decoupling. In the absence of more definitive information you
    would always place 0.1uF ceramic or larger on every supply pin to ground at the chip (_not_
    the far end of the breadboard, but within a cm or two so there is the minimum stray inductance
    in the wiring).

    Without proper decoupling there is nothing else worth speculating about as lack of
    decoupling causes all sorts of odd and mysterious symptoms.
  • Heater.Heater. Posts: 21,230
    Ah, I see, you mean that long black line running from top to bottom. Didn't notice any lines, my bread boards don't have such luxuries and both rails are split.

    6v is definitely a cause for concern if you are driving a 5 volt regulator which in turn is driving the 3v regulator. Might work with low drop out regulators (LDO) I forget the required head room off hand.

    What about driving the 3v regs directly from the batteries? At least for testing the Props work.
  • The 5V regulator that came with my PEK is an LM2940. This is an LDO regulator with a minimum input voltage of 6 volts. The PEK comes with a 9V connector. Using 4 AA batteries is a little iffy since the voltage will drop down below 6 volts after the batteries have been used for a while.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2015-12-08 15:59
    Heater. wrote: »
    Loopy,
    The fact that a crystal MUST be used for programing the Propeller or the EEPROM
    This is not correct.

    From reset the Propeller runs from it's own internal RC clock. The download/programming protocol is robust enough to tolerate any variance in that RC clock frequency. It's designed that way.

    Even if you do have a crystal attached it is not used until your program is loaded and you have specified your clock source to do so.

    Certainly my first Prop was a DIP welded to a strip board, with nothing but voltage regulator and associated Rs and Cs, and decoupling capacitors. It was programmed via USB/RS232 adapter and the transistor Prop programming circuit. Or via a Prop Plug.

    Heater you are 100% correct and I revised my entry. It seems that this is a situation that the user programed without a crystal, then found serial in/out wasn't working because he didn't know any further serial i/o requires one.

    The fact that he mentions the Propeller programing only 86% got me off track. That seems to be a combination of several practise that are not wise -- no by-pass caps, power from AA cells, possibly an incomplete or wrong voltage regulator configuration.

    It is much easier to avoid some of these problems with providing at least 7.2VDC battery power from 6AA cells. 4AA cells is marginal. And if one uses NiCad AA rechargible, 4 x 1.2VDC is 4.8VDCs.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2015-12-08 16:01
    The problem with the LM2940 is the way it operates in Low Drop Out mode. It consumes much more current as the input voltage sags. So the batteries are more quickly going dead.
    It may have delayed an immediate brown out of low batteries, but ended up browning out at 86% complete.

    Seems obvious that using a wall wart power supply instead of batteries might really clarify what is or is not working.

    ++++++++
    IMHO the worst part of changing to a crystal other than 5Mhz is that all the code examples that are timing sensitive will have to be revised. That adds a risk of math errors creating another source of bugs.

    To get started, use a standard and proven configuration with standard and proven code -- then explore changes at our own risk.

    As best as I can recall going lower than 5Mhz can be done easily. Going above 5Mhz seems to have risks of damaging the PLL circuits that multiple the 5Mhz up to higher multiples, so you should not use the PLLs. While I say 'should not', several people have challenged the 5Mhz limit with faster crystal and managed to survive - nobody knows the exact limit of individual chips. But once you hit it, damage is done and you have a Propeller that will no longer have teh PPL circuits.

  • As best as I can recall going lower than 5Mhz can be done easily. Going above 5Mhz seems to have risks of damaging the PLL circuits that multiple the 5Mhz up to higher multiples, so you should not use the PLLs. While I say 'should not', several people have challenged the 5Mhz limit with faster crystal and managed to survive - nobody knows the exact limit of individual chips. But once you hit it, damage is done and you have a Propeller that will no longer have the PPL circuits.

    5Mhz IS the recommended xtal, but even Parallax sells the 6.25 Mhz xtal that I believe Bill Henning sourced. This provides 100 Mhz speed. Many boards out there running at 100 Mhz. Most of my boards are changed to 6.25 because working with 10ns is easier than working with 12.5ns. 10 Mhz is normal also, (but PLL must be set to 8x). Even PhiPi used that in a production board that Parallax sold.
    https://www.parallax.com/product/28327

  • Heater.Heater. Posts: 21,230
    Never did get my 10MHz XTALS to work with a DIP Prop soldered to a strip board.
  • One other thought, are you using a USB 3.0 port? The have been problems reported based on the FTDI driver.
  • Bye to all, I think that one clear voice from a good source might solve the problem faster than all the cross-talk. If just makes it hard for the original poster to keep up.

    I believe that too much man power on one problem is occuring here.
  • Heater.Heater. Posts: 21,230
    You are right Loopy, throwing incorrect information into the pot does not help either :)

    We are all keen to help as best we can.

    Or should we all refrain from responding, knowing that someone who knows better than us will, who also doesn't because he's thinking the same? Resulting in no help at all !



  • Bye to all, I think that one clear voice from a good source might solve the problem faster than all the cross-talk. If just makes it hard for the original poster to keep up.

    I believe that too much man power on one problem is occurring here.

    You are correct. One call to Parallax Tech support might have solved the problem long ago. The fact that we just got pictures and no code just prolongs matters.

  • Heater. wrote: »
    Never did get my 10MHz XTALS to work with a DIP Prop soldered to a strip board.

    Andre sold a few Hydras through Parallax with 10 Mhz, albeit with the correct PCB layout.

    https://www.parallax.com/sites/default/files/downloads/32360-Elektor-Nov07-Hydra.pdf
  • Heater.Heater. Posts: 21,230
    This kind of issue has come up here many times over the years.

    I'm surprised Parallax has not put a working reference circuit in the datasheet by now, Component values and all.

  • johnprokojohnproko Posts: 121
    edited 2015-12-08 18:04
    The problem with parallax is that they just sell chips.
    Anyway I will print from the one that can print and use the other to communicate via xbee (if it is possible).
  • Heater.Heater. Posts: 21,230
    We should get to the bottom of why that second Prop of yours cannot print and otherwise behave with SimpleIDE.

    It's horrible to have these unknowns hanging around. They are always waiting to trip you up later. Then there is another three days running around in circles.

    I would swap the Prop chips on your bread board and hope to learn from that if it is a faulty chip or a faulty bread board layout.

    You should be able to assemble these in your sleep and have them work.
  • PublisonPublison Posts: 12,366
    edited 2015-12-08 18:31
    johnproko wrote: »
    The problem with parallax is that they just sell chips.
    Anyway I will print from the one that can print and use the other to communicate via xbee (if it is possible).

    They also have excellent documentation. Yes , it's 400 pages, but anyone that wants to use a MCU that they do not know, really should read it.

  • Heater.Heater. Posts: 21,230
    Publison,

    I find the Propeller documentation to be quite OK.

    But:

    It does lack any mention of decoupling caps or XTAL caps. It does not have a practical working reference schematic for the Prop. As this thread and many others before clearly show.

    It lacks a formal definition of Spin and the Spin byte codes. Kind of fundamental as the later are built into the chip.

    It lacks a definition of the protocol required to program a Propeller.

    These things are not a problem for those using a Parallax Prop board and using the Prop Tool but really, it's not complete yet.


  • johnproko wrote: »
    The problem with parallax is that they just sell chips.
    Anyway I will print from the one that can print and use the other to communicate via xbee (if it is possible).
    No, that is not the problem. Parallax has excellent customer support. I'm sure if you contact them they will help you out.

    It's doubtful that the Prop that can't "print" will work with any better with an xbee. Both functions require a working serial port. You are using 5MHz crystals on both Props, right? You did try changing the voltage input to the Props like we recommended, right? You did add decoupling capacitors like we recommended, right? So if one of the Prop still cannot "print" there must be something else wrong. Can you swap the Props to see if the problem is associated with a specific Prop?

  • Before swapping Props, add the freaking decoupling caps! Do it NOW! If their lack is what's causing Prop burnout, you don't want to ruin another one.

    -Phil
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