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Propellor on 5 hole breadboard? — Parallax Forums

Propellor on 5 hole breadboard?

maldridgemaldridge Posts: 37
edited 2011-02-05 20:25 in Propeller 1
I am trying to assemble the 40pin version of the propellor kit on a 5 hole breadboard I already own. Are there any resources (anyone done this who can post pics?) or do I need to order the right sized breadboard? Ideally, a modified diagram similar to the one in the propellor education kit is what I am looking for.

Comments

  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-04 10:09
    How is a "5 hole breadboard" different than the breadboard used in the PEK?

    Welcome to the Propeller Forum.

    Duane
  • maldridgemaldridge Posts: 37
    edited 2011-02-04 10:15
    If you look closely at the diagram in the books, you will notice that the breadboard there has 6 holes in each column. The breadboard that I am using only has 5 to a column.
  • b.p.m.b.p.m. Posts: 59
    edited 2011-02-04 10:39
    do you mean something like this:
    keyboard input, vid out, sd socket, headers for spare pins to come.
    it cost about $21 canadian for moost of it but used spare and salvaged parts.
    i have PROPDOS burned on the eeprom.
    blake
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  • schillschill Posts: 741
    edited 2011-02-04 10:49
    Duane Degn wrote: »
    How is a "5 hole breadboard" different than the breadboard used in the PEK?

    maldridge wrote:
    If you look closely at the diagram in the books, you will notice that the breadboard there has 6 holes in each column. The breadboard that I am using only has 5 to a column.

    I'm very fond of the Parallax breadboards because of this feature. They are the only ones I've ever seen that have 6 contacts in each row instead of 5. I stock up on a few more every so often when I place orders with Parallax.

    You will be able to build the circuit using a breadboard with only 5 contacts per row, but you will have to rearrange things slightly if you are trying to follow the documentation. If you understand the actual connections that are being made and don't just try to follow the picture it should not be too difficult.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-04 11:05
    Wow, I never noticed the PEK breadboards had six holes. Cool.

    I looked through the PEK again and I didn't see any examples of using all six holes.

    I've set up 40 pin DIP Props on my five hole breadboards many times. I never noticed the breadboards in the pictures have six holes. I don't think it should be any problem to use your five hole breadboards.

    I think I'll make sure and add some of Parallax's breadboards to my next order.

    Let us know if you still have trouble. If needed, I'll set up a Prop and take some pictures using my breadboard.

    Duane
  • maldridgemaldridge Posts: 37
    edited 2011-02-04 11:29
    This is what I've got right now, but it's reading zero ohms across VDD and ground. Attached is a picture of the current setup, I apologize for the poor quality, my iphone 4 hasn't come in yet.:smile:
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  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-04 12:14
    Are all your other parts the same as in the PEK?
    Make sure and double check your wiring using the schematic in the PEK. Don't just rely on the pictures.
    I agree the zero ohms across VDD and ground is something to be concerned about.

    I can't really see how everything is connected in your photo.

    Be aware, if you have different regulators than those used in the PEK, the pin outs may be different.
  • maldridgemaldridge Posts: 37
    edited 2011-02-04 12:18
    these are the parts in the dip plus kit. I assumed that they were functionally the same as those in the PEK so I used the diagrams in the PEK manuals. Is this not the case?

    This is how I thought it should be wired from the diagram in the manual. If some kind person wouldn't mind, can they post a picture of how this should be connected on a 5 hole breadboard? I suspect that I may have something crucial connected wrong due to my limited knowledge in reading schematics.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-04 13:28
    I don't know how much or how little you know so I apoligize if I say things you already know.

    Do you know how the breadboard is connected inside? Each group of five holes is connected together.

    The sides are connected to form power buses. Some boards the power bus only goes half way down the board so you'll need a small jumper wire to continue the bus all the way down the board.

    Do you know how to tell the positive and negative sides of the capacitors? How about the LED?

    The trickest part I think is keeping the pins of the regulators straight (in your head, I'm not worried about bent pins).

    According the datasheets these regulator have the ground pin in the center. Do you have a wire connecting both ground pins?

    The left pin (with the large tab away from you) is the input pin. The right pin is the output (either 5V or 3.3V). Hopefully this will make following the schematic easier to follow.

    Let us know if you are still having trouble.

    If someone else doesn't help you more, I'll be able to this weekend.

    Back to my day job.

    Duane
  • mickalmickal Posts: 75
    edited 2011-02-04 14:17
    I used pages of pek pdf 28 - 32 to put it together. It says what is connected where. I did not notice I had a 5 hole and they had 6 hole. It all worked.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-04 14:41
    Heck, who needs a day job.

    I think the PEK does a good job of showing and telling how to set up the Prop but I do think the power supply portion of the wiring isn't completely clear.

    You want the positive lead of a capacitor connected to the Vout of each regulator. The Vout of the 5V regular is connected to the Vin of the 3.3V regulator. (So the 3.3V regulator has a capacitor on both its Vin (shared with 5V Vout) and Vout.)

    The negative lead of each capacitor is connected to ground (somewhere either the ground bus or the where a center regulator is connected).

    Let's make sure you get this figured out. The Prop is just too much fun not to use.
  • TubularTubular Posts: 4,717
    edited 2011-02-04 14:42
    It looks OK to me, but its hard to see the power regulator section. I'd be removing the regulators and seeing if they are causing the short. Divide and conquer that bit. The rest looks fine, I assume the EEprom goes in that hole in the middle.

    What mode on the multimeter are you using to check for shorts? Ohms? Diode check? Continuity (buzzer)? Does it show ohms or voltage drop and if so what value? Sometimes I try reversing the leads (polarity) to see if its a genuine short, or just a diode conducting somewhere which can indicate a backwards IC or regulator

    Once you get past the short circuit issue, you'll probably be fine. But if you get some glitches or weird results there are two features most prop circuits have that seem to be omitted here - a pullup resistor (2 to 10kohm) on the SDA line (P29 on the prop), and one or two 100nF ceramic bypass capacitors right at the prop power pins
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-04 15:14
    The PEK shows a 10K resistor on the SDA line but it doesn't show bypass capacitors. I've set up a Prop using the PEK schematic and it worked fine. I do agree bypass capacitors are a good idea but I doubt that is causing a problem in this case.

    I think the wiring diagram (Figure 3-5) doesn't quite show the capacitors clear enough. Hole L3 of the center board holds the positive lead to a capacitor. It looks like it could be a wire to the ground bus (it's not). The negative lead of the same capacitor is connected to the ground bus.

    I looks like the positive lead of the other capacitor is connected to K5 (any hole in line with Vout of the 3.3V regulator will work). The negative lead is connected to J6 (any ground will do).

    I think the rest of the diagram is clear.
  • maldridgemaldridge Posts: 37
    edited 2011-02-04 15:40
    To answer some questions:
    • I use the multimeter in ohmeter mode
    • It measures 0 ohms both true and inverted on bus connections
    • As far as I can tell, the power regulators are wired correctly (no shorts there)
    • The capacitors are oriented correctly
    • Yes, I can identify basic electronic parts and thier polarity! (learned that one with 110!)

    I think that I will try to pull everything off that is not part of the power regulator and go from there. I'll post my results.

    Also, my breadboard does have the break in the power busses and I do have the proper jumpers in place.
  • RonPRonP Posts: 384
    edited 2011-02-04 16:09
    Welcome to the Forums maldridge,

    You might have already seen this but in case not here is "The Box Insert 40Pin DIP" attached PDF.

    -Ron

    PEKit_40PinBoxInsert-v1.2.pdf
    pdf
    pdf
    PEKit_40PinBoxInsert-v1.2.pdf
    4M
  • maldridgemaldridge Posts: 37
    edited 2011-02-04 16:30
    those are the schematics I was working from
  • avsa242avsa242 Posts: 454
    edited 2011-02-04 17:09
    I don't know if I'm seeing what I think I'm seeing, but is that crystal (if it is a crystal :) ) at the top of the pic tied directly to your power input? I'm not sure I understand why, if it is (I'm far from being an engineer, or even a student).

    Cheers,
    Jesse
  • TubularTubular Posts: 4,717
    edited 2011-02-04 18:21
    So time to divide and conquer. Why not temporarily disconnect the single red and black wire that "cross the chasm" just above the regulators in your photo, linking the top half of the breadboard to the lower half? See which side (top half or lower half) has the 0 ohm short.
  • schillschill Posts: 741
    edited 2011-02-04 18:53
    avsa242 wrote: »
    I don't know if I'm seeing what I think I'm seeing, but is that crystal (if it is a crystal :) ) at the top of the pic tied directly to your power input? I'm not sure I understand why, if it is (I'm far from being an engineer, or even a student).

    Cheers,
    Jesse

    I think that might be it. Look closely at the PDF. The crystal is plugged into the rows between the +V and GND. Is yours connected to +V and GND?
  • maldridgemaldridge Posts: 37
    edited 2011-02-04 19:19
    I rebuilt the voltage regulator circuit. I wound up eventually removing everything that wasn't part of the regulator circuit because the busses were being fed from two or three different points. I now have all the proper voltages on the busses. I will put the wiring for the chips back tomorrow and will post my results then.
  • maldridgemaldridge Posts: 37
    edited 2011-02-05 19:40
    I have rebuilt all the circuits that go to the chips and from what I can tell, the chips are booting properly. The power light even glows faintly when the serial connection is connected. However, the propellor development environment is unable to locate the chip. Any ideas?
  • RavenkallenRavenkallen Posts: 1,057
    edited 2011-02-05 20:19
    @Maldridge... Have you installed the necessary drivers for the Prop plug? If the power led comes on that means that the device is working some. Double check your wiring and make sure that power is applied to the circuit..
  • maldridgemaldridge Posts: 37
    edited 2011-02-05 20:25
    I use several other products with FTDI chips, I am aware that they need drivers and I have the proper ones installed.

    I finally traced the connection to the crystal. It's metal underside was contacting the power feed at that side of the propellor and preventing it from getting any power. The ground lead was missing on the other side so there was obviously no power there. I have corrected all the wiring errors and it now works!
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