YES! YES, for most prototypes Yes, they are a great way to test ideas.Originally Posted by Kenjones1935
-Adam-
|
solderless bread-boarding
YES! YES, for most prototypes Yes, they are a great way to test ideas.
-Adam-
Ohm it's not just a good idea... it's the LAW !
|
Took a quick look at the schematic and you will need a regulator from the 6 volt battery pack...
As for the bread boards.
Good, bad, and ugly....
That is all I use for proto-typing. Then when I am happy with things I get the soldering iron out.
Dave
Always wear safety glasses while programming.
|
Analog to digital conversion PIC16F887
Folks,
OKAY: Details.
My reading of the PICkit 2 Users Guide tells me that AN0 is connected to the on board potentiometer. AN1 is available for my use.
I need to connect the light sensitive resistor to an analog to digital converting input. Please confirm that I am getting this correct.
Pin 20 is A to D input AN1 and available.
It has an input resistance of at least 1Kohm
I can choose my reference voltage to be either Vdd or Vss.
I would install a 1Kohm resistor from Pin 20 to Vdd.
If I were to choose a CDS cell that varies from 1Kohm in darkness to 24Kohm in bright light do you think the A to D on pin 20 could discern the difference?
Yes, a voltage regulator on the six volts. Thank you.
Ken
|
Current consumption PIC16F887??
A 5 volt regulator has been suggested. I need to know the power requirement.
I have looked but not found the Microchip spec of the current consumption for the PICkit 2 or for the 16F887 chip itself.
Do you guys know where to look or know the value off hand?
Ken
|
Picbasic.co.uk disappeared for a couple days
Anybody know what happened?
|
I am not sure if there is any one answer. It would depend on the work being done by the chip. ~~How many things and at what current is the PIC driving? LEDs for example.
But saying that..... 1 amp should do for the regulator specs.
Dave
Always wear safety glasses while programming.
|
How does the Electronic Speed Control know??
The undisturbed connection between my Fatuba receiver and my ESC box has three wires, black, red, and blue. The black is GND (reference), the red is Vcc (hopefully a regulated 5volts), the third is the signal from the receiver to the ESC telling it which direction and how fast to spin the wheels (what voltage and which polarity to feed the DC motor.)
This is pulse width modulation. How is this information encoded?
My guess is that a square wave (50% Vcc 50% reference) tells the ESC to not power the motor at all. A larger than square wave pulse stream says to feed the motor positive voltage proportional to the area under the pulses. A smaller than square wave pulse indicates to reverse the voltage polarity and feed power inversely proportional to the area under the pulses.
Am I close enough for government work?
Ken
|
I bought a Radio Shack 2 1/8 inch IC breadboard socket kit. It looks just like one in your picture.
I am confused on how to use it. I have some dtdp switches that are dual twelve pin packages. They snap into the breadboard just fine, but not over the channel. Hence (if I understand which pins are connected to which correctly) the opposite pins are shorted to each other.
I have a dual inline socket into which the dpdt switch fits fine. It fits bridging the channel of the breadboard. That is what I expected. However, the pins do not snap into place. They are not allowed to become fixed. Could they be too big? I thought everything was standardized.
Our Radio Shack stores are down in inventory and the sales folks know nothing about these pieces.
Ken
|
I do not know anything about the Fatuba, maybe Alan knows...
Unfortunately not everything is standard, most are and the one that are not can be adapted in some way. Might have to make an adapter.
In my picture there are a couple surface mounts, a SD card socket, a 68 pin PLCC, and a part that has the pins at 1 mm.
So I guess I do get the soldering iron out before the project is completely proto-typed.
Dave
Always wear safety glasses while programming.
|
Breadboarding questions.
I do not see the value of the lower third of the PICkit2 printed circuit board. It looks like I am supposed to use it to breadboard, but there are no holes. Am I supposed to have the skill to solder to the individual PC pads?
I have purchased two different Radio Shack breadboard cards that require soldering. Do I place the components on the side that does not have the PC copper with their legs extending through the holes then solder on the side with the copper? This seems to work fine with the inline dip sockets (as opposed to their uselessness on the solderless board. The problem with that technology is that the legs of the inline dip sockets are not round. They do not snuggle into the springs.)
For drawing a circuit diagram I am using Photoshop. It is not obvious how to draw straight lines with that application, but I have a book....
Ken
|
I think I know my problem
The inline DIP sockets that Radio Shack sells are intended for surface mounting. Their legs are tiny rectangles in cross section (not circles as with wire). If I go to Do It Yourself Electronics they will have DIP sockets intended for solderless breadboarding.
Does that sound correct?
Ken
|
You mean the 44-pin demo board? Yep, it's place to put parts... Plenty of room for 1 or more IC's in SOIC packages, several places to put parts in SOT23 packages, and lots of pads for resistors and caps in 0603 or 0805 packages.
And yes, it's possible to solder them by hand with a good strong magnifying glass, lots of light, and a very fine tipped iron. It's easier with a bit of solder paste and a hot air station with a fine nozzle.
Welcome to the world of surface mount devices.
Yes, typically on the breadboard, parts are inserted on the non-coppered side and soldered on the copper side. I always have used plain "unclad" breadboard, and don't have much experience with the copper coated stuff.
|
Not quite sure what you're asking here. For the solderless breadboard, why would you use a socket? I always used to just stick the IC into the board...
|
The problem is.....
I have AXICOM P2 20941 DPDT relay switches. They are 12 pin dual in line configuration. The distance between the two rows of pins is .2 inches not enough (.3 inches) to bridge the channel in the solderless board. I need the DIP socket to make the necessary adjustment in width.
I hope to use the solderless boards at least to get started. They are sooo much easier.
A problems is that the hobby level RC components use three wire Z connectors; the radio receiver, female; the Electronic Speed Control, male; the Servo, male. I need to attach these to my circuit board. It is these lines that are switched by the DPTP relay switch.
Ken
|
HELP! The pin designations don't match
Fellow MicroChip PICers,
I have a PICkit 2. On the board is a PIC16F887. It is printed on the chip. I can read it with a magnifying glass. Also on the board are clearly marked in white ink the signal designations. These marks agree with page 36 of DS41296B 44-PIN DEMO BOARD USER'S GUIDE.
On page 8 of Microchip's DS41291F "PIC16F882/883/884/886/887 Data Sheet is the pin designations for PIC16F884/887.
The printing on the circuit board and the diagram on page 8 do not agree. On the circuit board PIC pins 33 and 34 are not connected. On page 8 these pins are RA6 and RC0 respectively.
On the circuit board these designations are given to PIC pins 31 and 32 respectively. (see attached)
What is UP?? and HELP???
Ken
|
I have another question
To run a Radio Control car from the PIC I need to create two PWM signals. One for the Speed Control that controls the drive wheels and one for the Servo that controls the steering. I see that I am to use CCP1 and CCP2 as outputs.
I also need to interpret a PWM signal (on radio channel 3) which tells the PIC to toggle between radio control and autonomous control. The information on this channel is simple. It is binary, but it is still PWM (I believe).
I am under the impression (mistaken I hope) that the PWM interpreter requires that CCP1 be an input. PLease see "Enhanced Capture/Compare/PWM(CCP1) chapter 11.1, page124 of DS41291D.
Do I have another choice for a pin to connect to channel 3 of the radio receiver?
Ken
|
Your board has a 16F887 in a TQFP package, not DIP, right?
See page 12 for the TQFP pinout...
steve
|
About the PWM.
You might be able to use the PULSIN command and pretty much any pin can be used with that.
I do not know the signal you need to read so this is just a thought.
Dave
Always wear safety glasses while programming.
|
TQFP is the answer...
I awoke this morning with the thought that those three and four capital letters in the upper left hand corner of the diagram could be significant. I went to page 8 then 9 and 10. That's it. What does TQFP and QFN stand for? At second glance I see one is for a printed circuit and the other is for a socket. Details! Details!
Thank you for the PULSEIN suggestion. I think that is what I need.
I have not prototyped since 1973ish and then I had a technician to physically build the circuits. I am hesitant. First I should get the three power supplies (7.2V battery pack, 6.0V battery pack, 5.0V USB) installed, regulated and grounded. I wish I had an oscilloscope.
(Oh for the good old days of upright analog Tektronix.) You'd think they'd be on the yard sale/antique market.
I shall keep you all in touch.
Thank you for being there.
Ken
|
TQFP is the answer...
I awoke this morning with the thought that those three and four capital letters in the upper left hand corner of the diagram could be significant. I went to page 8 then 9 and 10. That's it. What does TQFP and QFN stand for? At second glance I see one is for a printed circuit and the other is for a socket. Details! Details!
Thank you for the PULSEIN suggestion. I think that is what I need.
I have not prototyped since 1973ish and then I had a technician to physically build the circuits. I am hesitant. First I should get the three power supplies (7.2V battery pack, 6.0V battery pack, 5.0V USB) installed, regulated and grounded. I wish I had an oscilloscope.
(Oh for the good old days of upright analog Tektronix.) You'd think they'd be on the yard sale/antique market.
I shall keep you all in touch.
Thank you for being there.
Ken
|
Sounds right to me. Get the power supplies working like you want first.
Put maybe a 75% load on the 6 volt to 5 volt regulator just to make sure all is good.
No scope.... A good voltmeter will do. If you spend a little more on a meter you can get one that will read frequency. Kind of does the same thing when checking for a "dirty" power supply.
And capacitors. Use plenty. I bought a bucket of 22uF some time ago so I use them. Place them across VDD and VSS. Even when using batteries the capacitors help a lot. Motors involved. They are a must.
Dave
Always wear safety glasses while programming.
|
DIP = Dual Inline Package
TQFP = Thin Quad Flat Pack
QFN = Quad Flat No-lead
Watch Craigslist. Maybe one will show up in your area..I wish I had an oscilloscope.
(Oh for the good old days of upright analog Tektronix.) You'd think they'd be on the yard sale/antique market.
Say, where IS your approximate location? Maybe someone on the list is local to you and has one or knows of one you could get cheap.
You can also put a resistive divider the line in jack on your sound card and use one of the many available O-scope programs for your computer...
steve
|
The other Dave tells about the sound card trick here
http://davehouston.net/learn.htm
Dave
Always wear safety glasses while programming.
|
Hello, I am back.
Mucho frustration.
I could not get my DPDT mini-relay switches to work. I unwittingly purchased the "latching" kind with two coils. Neither I nor wikipedia know how these work. Today I ordered the same kind that http://letsmakeroborts.com/node/928 used. 5 to 10 days delivery by land.
I have succeeded in separating the 6volt battery (powers the PICkit, the radio receiver, the steering servo and the proto board) and the 7.2 volt battery (powers the wheels and the electronic speed control). Under radio control the car still runs.
Next step CCP1 and CCP2 pin outputs to the speed control and the servo.
Ken
|
Wikipedia? Hmmm. I imagine the manufacturer has a data sheet available for them. Do they have a part #?
I thought it was 1 if by land, 2 if by sea.Today I ordered the same kind that http://letsmakeroborts.com/node/928 used. 5 to 10 days delivery by land.
Must be thinking of something else....
steve
|
No details from manufacturer
AXICOM, part of TYCO, has a 15 page .pdf file giving the specs to their P2 V23079 Relay product line. No where does it say how, exactly, a latching relay works. It must be common knowledge except hereabouts.
I have never coded in BASIC. I know C and C++ and a few (if I could remember them) older languages. Today I wanted to see what is being INCLUDEd when at the beginning a program I see:
"include 'M16F88x.INC' ; PM header" see below.
Today my question is about PBP INCLUDE files. (see below example) Where are NOLIST and LIST and ifdef and XALL defined? Not, as far as I can find, in the smallish MicroEngineering Labs PICBASIC PRO Compiler booklet. Is there a more complete spec on the WEB? I assume there exists a well constructed public PBP library. Where do I find "intrc_osc_noclkout" (see below code)? When I was working each company I worked for maintained its own C libraries. Is that the way this world works?
;************************************************* ***************
;* 16F887.INC *
;* *
;* By : Leonard Zerman, Jeff Schmoyer *
;* Notice : Copyright (c) 2009 microEngineering Labs, Inc. *
;* All Rights Reserved *
;* Date : 07/02/09 *
;* Version : 2.60 *
;* Notes : *
;************************************************* ***************
NOLIST
ifdef PM_USED
LIST
include 'M16F88x.INC' ; PM header
device pic16F887, intrc_osc_noclkout, wdt_on, mclr_on, lvp_off, protect_off
XALL
NOLIST
else
LIST
LIST p = 16F887, r = dec, w = -302
INCLUDE "P16F887.INC" ; MPASM Header
__config _CONFIG1, _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_ON & _LVP_OFF & _CP_OFF
NOLIST
endif
LIST
|
No, the data sheet isn't very specific about how it works. But it appears from this data sheet, that you energize one coil to "latch" the relay on, and enrgize the other coil to release it. Or you can reverse the polarity on a coil to reverse its effect (e.g., one polarity to latch, and reverse polarity to release.
I think the
http://relays.tycoelectronics.com/datasheets/p2.pdf
At the bottom of pg 4, right hand most of the 3 diagrams, (where it says
"Contacts in reset position. Both coils can be used either as set or reset coils.". I think that bit applies to your relays. You can either energize one coil to "set" the relay and the other coil to "release"..., or you can use one coil and hit it with one polarity to "set", and reverse polarity to release".
steve
|
Hi Ken,
Those are assembly language instructions, find them in PIC data sheets.
Section 15.
Last edited by Archangel; - 16th January 2010 at 05:22.
If you do not believe in MAGIC, Consider how currency has value simply by printing it, and is then traded for real assets.
.
Gold is the money of kings, silver is the money of gentlemen, barter is the money of peasants - but debt is the money of slaves
.
There simply is no "Happy Spam" If you do it you will disappear from this forum.
|
Ken,
You will also want to look in the C:\Program Files (x86)\Microchip\MPASM Suite for the *.inc file for your chip. That is where you will find all of the config options, near the end of the file.
To learn a little more about PBP and includes try this.
Start a new project, leave it blank and compile ( you may have to put the configs in you code space if that is the way you are doing it, but nothing more).
Looks at the ASM generated. PBP will do all of the setup from the default includes.
Now add
INCLUDE "modedefs.bas"
to your code. Compile again and look at the ASM file.
Dave
Dave
Always wear safety glasses while programming.
|
Looks like I've got to do some studying....
You all posted in the "PBP projects for R/C models" thread code specifically for the 12F675. My PIC is a 16F887.
I am at a loss to translate from one PIC to the other. My PBP compiler (set up for 16F887) has no idea what to do with GPIO.x references. When I set it for 12F675 it is happy, but the resulting code is useless to my PICkit2.
Is it my job to read about the 12F675 and try to figure out which register in my 16F887 is equivalent? That would be an excellent homework assignment.
Ken
|
Yup, pretty much your job to pull the data sheet and compare pin/port assingments.
Even if you found code for the PIC you are using the pin assingments would probably be different from your setup.
The ADC and other built in hardware things can be confusing from PIC to PIC. So when those kind of things come up we can help you there.
Dave
Always wear safety glasses while programming.
Members who have read this thread : 1You do not have permission to view the list of names.
Posting Permissions
Bookmarks