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Can't find Propeller any more — Parallax Forums

Can't find Propeller any more

propwellpropwell Posts: 87
edited 2010-01-26 17:14 in Propeller 1
Hi friends,

i can't understand what is going on over here. I've got the gadgetgangster.com Propeller Platform Module, it was running very vell over a few weeks.
As i wanted to try a new code today, Propeller Tools says that it couldn't find any propeller chip on any serial port! I've got the board connected via PropPlug!
THe Program i have running on the EEPROM seems to run properly, as it sends values via RS232 to my serial terminal on the PC!
So the Propeller seems to run, but is not detectable! Is it possible that i destroyed just a part of the prop?

Thank you for your help,
Max

Comments

  • JonnyMacJonnyMac Posts: 9,230
    edited 2010-01-19 17:05
    Sounds more like a problem with the PropPlug -- it needs to be able to reset the Propeller for programming. In a pinch, you might try pressing the reset switch on the board right after to click download in the IDE. Yeah, it's like catching a fly in the middle of a tornado, but you might just pull it off.

    Of course, it could be a loose connection. Pull out the PropPlug and give the header a bit of a squeeze to increase the tension of the header pins going into the PropPlug.

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    Jon McPhalen
    Hollywood, CA
  • propwellpropwell Posts: 87
    edited 2010-01-19 17:16
    hm yeah tried resetting the prop as programming but didn't match the right point of time.
    Hm when i stick the PropPlug in and i check the connection with my multimeter, everything looks ok, the Pins of the PropPlug are connected to the pins at the propeller.

    hargh... i hate these problems....
  • propwellpropwell Posts: 87
    edited 2010-01-19 18:06
    maybe a destroyed prop-plug? But it is found as COM27 in WIndows!
  • CassLanCassLan Posts: 586
    edited 2010-01-19 18:07
    Just a curiosity, have you restarted the computer?

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  • propwellpropwell Posts: 87
    edited 2010-01-19 18:10
    yes. it is also possible to programm another board of mine, which doesn't use the PropPlug... But that works!
  • propwellpropwell Posts: 87
    edited 2010-01-19 19:10
    hmm maybe it has something to do with the ADC i've connected. It's the MCP3208. Here is how i connected it!
    As i wanted to measure a voltage on my board, i connected the analog-ground with the ground for the mcp.
    The VRef is the maximum voltage i want to measure, which is also the 3,3V-Voltage, this is why i connected the VRef and the VDD-Pin!
    For testing, i connected Channel 0 with the 3,3V-Voltage line (i expected to get a 255, which i finally got).

    Could there be a problem?

    I tried this board on another prop board. Firt it worked, it sent me all the values i wanted to see. But as i shut the prop off and on again, propeller tool wasn't able to find the prop anymore, although i haven't connected the board anymore!!
    WAAAAAHHHH looks like i destroyed both propellers!

    Here's the code i use:
    CON
      _clkmode = xtal1 + pll16x
      _xinfreq = 5_000_000
    
      BaudRate      = 9600         'Baud                               
      RxPin         = 31            'For RS232                          
      TxPin         = 30            'For RS232                          
      CommsMode     = %0000         'See SerialMirror.spin for meaning   
      
    OBJ
    
      mcp           : "MCP3208"
      sm            : "SerialMirror" 
      
    PUB main | adc
      sm.start(RxPin, TxPin, CommsMode, BaudRate)
      dira~~
      outa:=1
      dira~~
      outa:=0
      mcp.start(6, 5, 7, 0000000000000001)
    
      repeat
        adc :=  mcp.average(0,10)
        sm.tx(adc.byte[noparse][[/noparse]0])      
        sm.tx(adc.byte)
        waitcnt(cnt + 100_000_000)
    
    


    i used Pin 3 (High) for the VRef/VDD-Line of the MCP and Pin 4 (Low) for the GND/AGND-Line of the MCP. Is that not allowed?
    800 x 534 - 24K
  • JonnyMacJonnyMac Posts: 9,230
    edited 2010-01-19 19:51
    I don't think it's a good idea connect Din and Dout directly to each other -- I would put a 1K resistor between Dout and Din, then connect the Propeller pin to Din. That way, if the Propeller pin is an output when the ADC is output data on Dout you don't have an electrical conflict.

    It's not like that this would have destroyed your Propeller chips, still, developing good design habits that protect from programming errors is important.

    [noparse][[/noparse]Update] Do you realize that dira~~ makes all of your IO pins outputs? -- probably not a good idea; you should focus on the pins you need. If all pins are outputs then you could have a conflict on P31 which is normally set to input mode for receiving serial data from the PropPlug. You'd also be writing a 0 to P30 which would look like a start or 0 bit on P30. Remember, if any cog makes a pin an output then it's an output.

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    Jon McPhalen
    Hollywood, CA

    Post Edited (JonnyMac) : 1/19/2010 7:59:09 PM GMT
  • propwellpropwell Posts: 87
    edited 2010-01-19 20:17
    hm ah ok... you think that maybe i can't program the prop anymore, because P31/31 are set to output at the beginning of the programm, and that's why the program can't find it?
    i Think it should help to start the prop without the eeprom?

    and the problem with DOut and DIn: Thats how it's written in the MCP3208-driver!
  • Miner_with_a_PICMiner_with_a_PIC Posts: 123
    edited 2010-01-19 20:31
    propwell - JonnyMac is offering good advice. You should note in hindsight that your code with its errors (linking outputs to outputs in states not accounted for) placed your setup at risk of damaging the ADC, the prop plug and/or the propeller chip. If they are all okay then you are fortunate but why leave damaging your hardware to fate? We all make mistakes and in the prototyping phase it is often wise to adopt "the ounce of prevention is worth a pound of cure" approach. This has saved me a lot of trouble so many times. A series resistor in line with any output (or input, that whoops became an output) will tend to limit currents...later on if you choose in the final design they may be removed...or left in place.
  • propwellpropwell Posts: 87
    edited 2010-01-19 20:40
    yeah that certainly sounds good, no question. And i'll surely do that!
    But i'd be glad if could get my prop-board working again. If i can identifiy my prop again, i'll start a new approach with the ADC (it isn't connected anymore) and, to be sure, there will certainly be some more resistors [noparse]:)[/noparse]
    Well, i disconnected the EEPROM and tried to programm the RAM - but the PropTool still says no Propeller found! Do i have to buy a new Proppeller/EEPROM/PropPlug?

    Post Edited (propwell) : 1/19/2010 8:46:44 PM GMT
  • Miner_with_a_PICMiner_with_a_PIC Posts: 123
    edited 2010-01-19 20:58
    propwell, glad to hear. >> "Think it should help to start the prop without the eeprom?" This isn't necessary, just press F10 or F11 VERY shortly(within a second or so) after power up before the bootloader has an opportunity to load the prop program from the EEPROM...the bootloader will detect that you are updating a to new program from serial and take the appropriate actions.

    Edit >> Ouch, its either your prop or your prop plug that could have taken a hit...if you have another propeller chip try programming it. If you don't have a propeller chip handy then you could try to remove the prop from any hardware, connect the TX to the RX....NO OTHER CONNECTIONS....open up the "parallax serial terminal" (has the earth and a little computer in the shortcut icon) that comes with the spin programming tool. Set up your com-port, serial speed (any will do) and enable the port (lower right most button)...type text in the very top most box (grey colored), if all is well the same characters should show up in the blue output box.

    Post Edited (Miner_with_a_PIC) : 1/19/2010 9:10:01 PM GMT
  • propwellpropwell Posts: 87
    edited 2010-01-19 21:01
    unfortunately, it doesn't even work without the EEPROM. its a dip-package so i was able to remove it easily, but still - no propeller found.
    The strange thing is that the program on the EEPROM seems to be working fine (surely with the EEPROM connected [noparse];)[/noparse] )
  • Miner_with_a_PICMiner_with_a_PIC Posts: 123
    edited 2010-01-19 21:13
    One additional thought...if the above "edit>>" recommendations don't work...try one more time to verify the prop plug / new prop after unplugging the prop from the USB and rebooting your system. Sometimes when hardware gets shorted or overloaded it disconnects or the driver fails.
  • propwellpropwell Posts: 87
    edited 2010-01-20 07:11
    ok, checked the PropPlug like you said - works fine. I connected the RX to the TX of the Plug and all it does is mirroring the message.
    Looks like the Propeller got destroyed. Unfortunately, i don't have one handy, so i have to buy another one.
    But another question: Is there the chance of a possibility that the error came from my USB-Cable / Computer? I have another board, which i want to program that week, but now i'm a bit in fear of destroying that one to, and that would be the biggest catastrophe ever!

    Thank you!
  • rjo_rjo_ Posts: 1,825
    edited 2010-01-20 07:57
    It is pretty hard to kill a Prop, but you can make them bitter. Try running it without the pll16. I have had the experience of shocking a couple of Prop Plugs with the same mistake and thinking it was the Prop. If all else fails, just put the plug aside and see if it doesn't behave better when you come back. There could also be an intermittent power supply problem. A have several board from Phildapil and never had a problem... one day things went wierd and it turned out that one of the surface mounted voltage regulators was lifting out of its seat. Easy to fix, but I was pulling hair trying to find the problem.
  • propwellpropwell Posts: 87
    edited 2010-01-20 07:59
    Hi rjo, thanks for your answer! The PLL16 is the quarz?
    I have let the propPlug lay aside the whole night, but in the morning, nothing changed. Power supply: I can measure a voltage of 3,28V and 4,99V on my Board, should be ok, or?
  • Nick McClickNick McClick Posts: 1,003
    edited 2010-01-20 08:17
    If you pull the prop out of the socket and put it in a breadboard w/o an eeprom, the propplug still can't reset it / load the ram? Like rjo said - I've done some really dumb things to my prop and I still haven't cooked one yet. Voltage looks fine. It might some intermittent problem, although it sounds unlikely.

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  • propwellpropwell Posts: 87
    edited 2010-01-20 08:22
    We'll, i've got the Propeller Platform Module from gadgetgangster. All it includes is the voltage conversion from 7.5V to 5.0V to 3.3V, an EEPROM, the PLL16 and the Prop. And as i said, without the EEPROM, it is not possible to program it.
  • BradCBradC Posts: 2,601
    edited 2010-01-20 10:55
    propwell said...
    We'll, i've got the Propeller Platform Module from gadgetgangster. All it includes is the voltage conversion from 7.5V to 5.0V to 3.3V, an EEPROM, the PLL16 and the Prop. And as i said, without the EEPROM, it is not possible to program it.

    A couple of things.

    Without the EEPROM,F7/ F10 should still work. F11 will fail. If you can't even get F7/F10 to work then there is something more sinister going on.

    If you have killed the PLL, then you will be able to load the prop and program the eeprom but if your program selects a PLL mode it just won't run.

    If you want to test your prop plug, put a resistor between the TX and RX pins and connect to it with hyperterminal (Turn hardware flow control off). If you can see what you type coming back then it's probably ok.

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  • propwellpropwell Posts: 87
    edited 2010-01-25 20:08
    Hi together,

    i got a new Propeller chip today and TA-DA: it works again. So, somehow i managed to destroy my Prop!
    Can anyone please explain me how to connect the ADC to my Propeller, without the chance to crash the whole board?
    here's the datasheet:
    http://www.farnell.com/datasheets/79094.pdf

    Thank you very much!
  • Miner_with_a_PICMiner_with_a_PIC Posts: 123
    edited 2010-01-26 05:20
    Propwell >> The ADC has three signal inputs (DIN, CLK and CS) and one output DOUT. Only the ADC's DOUT pin needs be protected with a series resistor between it and the prop, as it could go into contention with the propeller if they both happen to be an output at the same time and be in different states (i.e. prop outputs a zero and the ADC outputs a 1 and visa versa). A resistor on the order of 1K should do just fine especially in the prototyping phase and perhaps best kept in place permanently.
  • propwellpropwell Posts: 87
    edited 2010-01-26 07:26
    ok, and what if i want to measure a voltage on the same board, and the voltage is for example the vdd-voltage (which doesn't really make sense, i know, nut just for testing reasons?)
  • Miner_with_a_PICMiner_with_a_PIC Posts: 123
    edited 2010-01-26 15:14
    The ADC comes with a Vref that is used as a voltage reference for the A-to-D conversions. The Vref voltage and the voltage on any pin for that matter CANNOT exceed Vdd (or go below zero) which is constrained to the range 2.7 through 5.5V depending on your application. For testing or in your final design it would be okay to tie the Vref to Vdd and the AGND to DGND. With such a set-up you would be able to measure voltages ranging from 0 up to VDD; if the voltage read on the analog input was equal to VDD you would get a digital value of 4095 which is full scale for this 12-bit ADC. If you need super clean, super accurate measurements in your final application then you should probably take care exactly where you connect your AGND and Vref, but for the most part I have had great success even in final applications with the aforementioned connection scheme.
  • propwellpropwell Posts: 87
    edited 2010-01-26 16:44
    yeah that sounds good. But is it allowed to connect the VDD-Pin of the ADC to a nromal Digital-Output-Pin of the propeller? And Enable the ADC by setting the Pin-Output to high?
    Or does it need to much current and destroys my Prop?

    Thank you all!
  • Miner_with_a_PICMiner_with_a_PIC Posts: 123
    edited 2010-01-26 17:14
    Propwell >> NO...do not do that as you could damage your ADC. At not time should any input of the ADC go outside of the range of 0 to VDD....so if you place VDD to zero volts(ADC turned off) and you have an analog input that is non-zero (typically the case) then you have violated the ADC's specifications...damage or parametric degradation could occur to the ADC. The only reason I can see for wanting to do this is to save power...but according to the spec sheet the ADC only draws 2uA when CS is not active (CS is high), so the gains would be minor in this regard. The CS already does what you are seeking to do, just connect your ADC's VDD continually and you will be set.

    Incidentally if you are concerned about damage to your ADC analog inputs from high voltages a >>MINOR<< amount of protection can be afforded them by adding a series resistor...see figure 4-2 on page 14 for more details...Since the expected degradation in performance is minor you might want to use these if your design is reliability centric. You would want to use the highest resistance for the given sample rate...take care that your clock frequency does not go below 10 KHZ (see section 6.2 Maintaining Minimum Clock Speed).
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