Pigmy Boards User Feedback.
PIGMY Boards: Sold out 4-Apr-99
For reference only.
The Table of Contents.
Crystal Capacitors Clearance || RS-485
Circuit || DB-25's || LINKS ||
Diode D3 || LEDs || Basic
and LEDs || FED Basic and LEDs || 50/60hz
|| LED Links || Cheap Comms
and Transistor Q3 || Finding Comms with FED Basic ||
Crystal Types. What Type do I buy? || FED
Basic, 8K, and Max-232 || MEL PicBasic, and yet
more links ||
This file is a result of user feedback. Whenever Users have asked questions,
or had a problem putting my Rev. B PIGMY PCB together, I have added to
this list. As time permits, I will adjust documentation and boards to new
requirements.
Crystal Capacitors:
Reset Button may have physical contact with the crystal caps if the caps
are too large. Make sure you use small caps or allow enough clearance between
these components.
Back to The Table of Contents.
RS-485 Circuit:
I must admit that the limited time I had available to achieve a quick result
meant that the RS-485 add-on circuit was flung in at the last moment. On
the 75176B's, pin 8 is +5 Volts, pin 5 is ground, pin 6 and 7 are the '+/-'
signals, and pin 2 should mate up with the triangle signal for the gate.
This is the receive enable.
Back to The Table of Contents.
DB-25's:
The DB-25 female connectors are drawn as shown from the solder side of
the board, that is, 13 pads. Looking at the top of the board it should
really show only 12 pads. If you use female connectors then they will only
line up one way with the board, however you may be confused with pin 20.
If you are installing the pin 20 jumper, then the position on the board
hole lines up with the correct pin on the connector.
Connectors must be female, and they will only mate up with the
board one way.
Back to The Table of Contents.
LINKS:
The total number of links on the boards is 17, plus the two cross links
near the RS-232 DB-25 pin 20 position. Read the PIGMY instructions for
full info about these two links. Most applications don't require the crossed
links at the pin 20 position.
Back to The Table of Contents.
Diode D3:
Diode D3 is shown on the overlay as being the same as a resistor standing
upright. The diode symbol is next to the upright resistor symbol. Don't
confuse this with Resistor R16.
Back to The Table of Contents.
LEDs:
LEDs are drawn with the black mark representing the cathode, or bar end
of the device. They may have a flat spot on the cathode end of the device,
or have the cathode leg shorter than the anode leg. On the overlay, the
cathode is shown as the down position on all LEDs.
Back to The Table of Contents.
Basic and LEDs:
Most of the PIC Basics won't work with the four RA0-RA3 LEDs (or links)
installed. The power LED can be installed, then later (link) removed for
low power applications.
Back to The Table of Contents.
FED Basic and LEDs:
Install LED3 or the RA3 LED, but not the other 3 LEDs (LED0-LED2), as this
will upset the operation of the EEPROM and RS-232 receive signals. Power
LED? Same as before, your choice.
Back to The Table of Contents.
50/60hz:
50/60hz INT for RTCC. (Not required in any of my projects). Unless you
wish to read the 50/60hz timing, you can ignore R1 and D2 and just link
J3 pins 1 and 2 together.
If you wish to use this feature on a PIC project, you will need
an AC transformer or plug-pack power supply to be able to sense the 50/60Hz.
You will also need to know how to program in Machine Code and as such would
have suitable data on the device.
Back to The Table of Contents.
LED Links:
J8, J9, J10, J13? (LED Links):
Yes, as J11 is the programming header, I would have to have a set of
DT001 instructions for the Rev. A PIGMY board, and another for the Rev.
B board, so I settled for keeping J11 as the programming header on both
versions.
Back to The Table of Contents.
Cheap Comms:
Transistor Q3 is shown incorrectly on the overlay and PIGMY board. The
flat side should be shown in the same directions as Q2 and Q4. This also
means that you will need to bend the centre leg of this transistor in order
to fit it into the board in the correct direction. Don't install R23 (10K).
Because of the brown-out circuit, reset will never work with R23 installed,
so ignore it.
Back to The Table of Contents.
Finding Comms:
FED Basic.
Robin's method of getting comms between the module and your PC, is
to power the unit down, put in the boot link, power the unit up, then remove
the link.
I have replaced the Boot link with a Boot Button, used LED3 as
a comms status LED ("OK=ON") to assist, and used the RESET button instead
of the power down sequence. I find that sometimes the comms restoration
proves a little tricky when using the Reset Button instead of powering
down.
The fix is as follows:
Isolate the Reset Button with two track cuts. Use a 1K resistor to
jumper Ground to one side of the Button. Connect the other side to the
Collector of Transistor Q1. Both of these are near the Reset Button pins,
so minimal work is involved. If there is a Rev. C Pigmy board, I will include
these changes.
Why is this so? I guess it's in the data book somewhere. The Micro
seems to require a signal level closer to ground than the one supplied
by transistor Q1. You must use a 1K resistor in series with the Button
as Q1 is normally switched on allowing +5Volts to be present on the reset
line. If a ground was placed on this line at the same time, an effective
short would be between +5V and ground, well through Q1 Emitter/Collector
at least.
Back to The Table of Contents.
Crystal Types:
In the Digi-Key catalog you will see Series and 20pf Crystals.
For most Microprocessor Applications, the standard specification is
20pf parallel resonance.
These are available in HC-49 or QC-49 tin cans. These are a small
upright can with legs at .2" centers. Frankly, I have just got crystals
off the shelf for years without knowing what type they were, simply because
most sales people don't know, and I don't expect them to. All crystals
have worked. These days I buy in quantities that enable me to order Microprocessor
specific Crystals. Even the Digi-Key Catalog specifies a 4Mhz series Crystal
for a 6809, and a 20pf for a Z80A, but then they also specify a 4Mhz 20pf
unit for a Z80 and these things don't run at 4Mhz.
Back to The Table of Contents.
Links Again:
The Pigmy board may be too versatile. Options are many. Here is another
alternative explanation of FED Basic, and 8K EEPROM, and Max-232 installation:
21-Jul-96
Stephen Conrad [conrad@mpx.com.au]
Subject: Re: PIC problems.
Stephen Conrad wrote:
Just a quick note to check the jumper settings for the Pigmy board
that you sent to me last week.
I have put the board together, and are having trouble communicating to
it from my pc. I'm getting the error "module not connected or in
error".
I have tested the com port and it tests fine. I figure that the serial
cable or jumper pins may be incorrectly set. I have set out the serial
cable as per instruction and have set jumper pins to :-
J3 - 1-2
J4&J5 - 2-3
J14 - 1-2
J17 - 2-3 2-3
J18 - 2-3
J19 - 2-3
What are the settings for J7, J14, and J15.
Must be something very simple, but i have missed it. TA.
------------------------------------------------------------
Hi again Stephen, print the file pigmyasc.html as per the instructions
at the start of the page.
For FED Basic with an 8K EEPROM, and a Max-232:
J3 1-2 correct. Pulls RTCC high.
J4&5 2-3 Correct. Uses Crystal.
J14 1-2. NO, this can be done to test for a loopback on your comms,
but you should pull your PIC Chip out before doing this.
J17 3-5 and 4 to 6. See Pigmyasc.html circuits. This directs the comms
to the Max-232. Where the circuits shows the word J17, this is right
next to pin 3, so pin 2 is the one close to the 'p' in cheap.
J18 You don't need to do anything around the J18 and J19 area, or even
the two crossed links for FED Basic. It is only a 3 wire serial
connection.
J7 is only used for the Printer port connection for the Counterfeit
Stamp one.
Now for the J14, J15, and J16 connections. Remember, this is for FED
Basic only and 8K EEPROM.
J14/1 to J15/3 (Input to RA2)
J14/2 to J15/4 (Input to RA3)
J15/1 to J16/2 (SCL EEPROM)
J15/2 to J16/1 (SDA EEPROM)
These connections can be found half way through the pigmy2.html file
and in the pigmyasc.html file.
Hope this gets you on your way. :) Don...
--------------------------------------------------------------
Sun Jul 21 13:09:56 1996
From: Stephen Conrad [conrad@mpx.com.au]
I worked all this out in the end, but thank you very much for the fast
response. I sat down and read the schematic for the circuit and could
very plainly see that my serial comms were going nowhere and also that
the 8k eeprom was connected to nothing as well. It's all up and
running now, so this should keep me busy for awhile. I may in the near
future order your relay board, so that I can start to control things.
Thanx again. Stephen Conrad
Back to The Table of Contents.
MEL PicBasic and yet more Links:
To: Graeme Levitt
Subject: Re: pic84 boards
Hi Graeme, hope this helps.
Graeme Levitt wrote:
>
> Don,
> I purchased a PIC84PGM and PIGMY rev B. Just a couple of questions:
> The program board
> 1.Above LED 4 hole drilled on diag shows link but to what
>From 84.html:
Install the DB-25 Male connector and the two links as follows:
(1) Link the board between the vacant hole near C4 and pin 25
(Ground) of the DB-25 Male.
(2) Link the board between the vacant hole near the Power Led to
pin 14 of the DB-25 connector.
I'll just repeat that again. I had one user ring me from New Zealand
to thank me for my prompt service and good product, however he also
poined out that I hadn't mentioned the jumpers on the component side
of the board that connect to the DB-25 connector and he had problems,
so here it is again...
(1) Link the board between the vacant hole near C4 and pin 25
(Ground) of the DB-25 Male.
(2) Link the board between the vacant hole near the Power Led to
pin 14 of the DB-25 connector.
> The PIGMY board
> 1.Below j19 a link is shown (vertical) but only one hole
provided > where does the other end go to.
This is from pigmy1.html:
There is a link that connects pins 6 and 8 together of the DB-25
female connector. This is used for my PICEX controller. You won't need
it for the Stamp work-alikes and FED Basic. If you do end up
installing this link, make it an insulated link that is connected over
the top of the DB-25 pin 20 link described below. (PICEX)
Another link must be installed after the DB-25 Connector is soldered
in, but leave this link for now. It will connect pin 20 DTR of the
RS-232 DB-25 connector to the centre pin of J19. (ATN/PICEX)
These links are for serial communications options and not required for
the PicBasic compiler unless you are using RS-232 routines via the
DB-25 connector.
> 2.Do I run a wire between the two points marked BOOT
BOOT is only used for FED Basic and not for MEL PicBasic.
This BOOT feature is covered in pigmy2.html.
> I'm not quite sure what to do to get the whole thing going. Ok to
power > it up etc. I bought a copy of Ueng Lab PicBasic. This appears to
compile my > basic file to make a suitable format file. How do I
communicate with your > programmer on the parallel port. As you can
see I don't quite understand > what software or where I get it to use
your set up. > I would appreciate a hand. > Thank you Graeme Levitt >
levitt@tiny.me.su.oz.au
Yes, I have found a few users floundering with the software, so I have
added some sample code to the PicBasic disk to assist. The easiest
software to use is NIGEL.ZIP. I have set up some defaults and included
them with this file to make it easier. Ealier versions of Nigel's
program had a problem with fuse settings. This was only the way
Parallax and MEL had set these out. The device type was embedded in
the fuse settings and Nigel now has changed his code slightly to cater
for this.
I have attached the file for you, but new users will be able to get it
from my home page and it is now supplied on disk with the purchase of
PicBasic compiler.
Cheers Don...
mailto: don@dontronics.com_
Copyright © 1996-99 DonTronics