“QuickieLab” Assembly & User Manual
Contents
1. Referring to the schematic you can see that the QuickieLab is based on use of a BASIC Stamp microcontroller The Stamp merely needs to be powered with 6to 12V dc from the QuickieLab s connector J1 and this self contained system on a chip is ready to go It contains an onboard 5V regulator for its computing logic and its own RS 232 levels for serial port connection to a PC Further the Stamp contains an internal non volatile memory that allows retention of the software program even after power is removed With this capability the QuickieLab can be programmed once i e it s software program needs only to be downloaded once from the PC and it can forevermore operate independent from the PC umbilical cord Take it out to the field with an appropriate battery supply or to your buddy s house and it ll operate the same as it last did on your bench 1 0 PINS DO ALL THE WORK The main purpose of any microcontroller is to input various signals do some computations based on those signals and then output other signals based on those computations Thus the Stamp s 16 I O pins are of great interest and utility to us in the QuickieLab Each of the I O pins is under software control and can be used to read the state of pushbuttons and keypad actuations as well as to send data to human readable devices like the LEDs and the LCD The I O pins are wired to a jumper block J10 located directly above the plugboard and the user may jumper an2. QuickieLab Assembly amp User Manual a BASIC Stamp platform for ham radio experiments 2 ee ae er Figure 1 The QuickieLab is a BASIC Stamp powered experimenters platform with a 16x2 character LCD for data and status display keypad for numeric data and command entry general purpose input output devices potentiometer pushbuttons LEDs speaker a frequency counter A D and D A converters a digital pot and an RS 232 serial port for downloading of Basic program experiments Provision is also made to accommodate an AD9850 DDS DaughterCard separately available from the NJQRP Club The Stamp s sixteen input output pins may be jumpered to an experimenter s plugboard for temporary addition of circuit components that work with the downloaded software in the BASIC Stamp to perform the experiments A prototype PC board is shown here The production version is soldermasked and silkscreened to assist in assembly INTRODUCTION Great feedback is regularly received now from readers on the latest string of microcomputing projects in QRP Homebrewer and QRP Quarterly magazines It s very gratifying and encouraging to know that many QRPers are interested in these digital projects When considering even more useful projects that QRPers can easily build right now the light bulb clicked on once again over a lunch with Joe Everhart N2CX We decided then that a perfect project would be one that provides a reusable test Quick
3. Copyright 2002 by George L Heron All rights reserved 2 The QuickieLab project website can be found at www njgrp org quickielab It contains more detailed construction and test information color photos I O Expander source code BASIC Stamp sample programs QuickieLab application notes and a complete listing of T O Expander commands and control characters 3 The I O Expander IC and Resonator may be purchased from the NJQRP Club See www njgrp org iox for ordering details 4 Read all about the BASIC Stamp at the Parallax com website www parallax com All software application notes and documentation are free for the download and great fun can be had while perusing this vendor s website 5 Questions concerning the QuickieLab may be directed to George Heron N2APB n2apb amsat org or Joe Everhart N2CX 2cx voicenet com We ll do our best to help you out as soon as possible Peter Anderson sells a BS2 Homebrew Kit that can be used with the QuickieLab PC board You can find details of this at www phanderson com stamp bs2_ homebrew html This 3 chip set of parts is about half the price of a BASIC Stamp 2 chip 6 1 1 Ji2 KEYPAD uw lt i Ca 5 IS SERIAL PORT ail Q e m O J2 ADC SX KET P2 P1 1 0 Configuration 12 23 5 6 7 BS 10111213 SOLDERLESS PLUGBOARD QuickieLab pc board layout QuickieLab Assembly amp User Manual v1 0
4. Copyright 2003 G Heron N2APB
5. DDS DaughterCard Provisions are made on the QuickieLab to accommodate the newest addition in the HC908 Digital Breadboard project family a DDS daughtercard This small board contains the AD9850 Direct Digital Synthesis chip its oscillator and the low pass output filters that all conspire to produce very precise and low noise frequencies from the sub hertz basement up to 30 MHz The 1 x 2 daughtercard plugs into socket J6 on the QuickieLab and enables the homebrewer programmer to generate a very precise and accurate signal source It can be useful as a VFO a test signal source a local oscillator in a test receiver or even as an audio oscillator when patched into the built in speaker on the QuickieLab CONSTRUCTION Building up the QuickieLab is straightforward The list of parts is provided in this manual and components are easily acquired from Mouser Electronics Dig Key and the NJQRP Club You might even have some of these common parts already in your own junkbox Assemble all components on the PC board by carefully following the Parts Layout diagram Some specific notes QuickieLab Assembly amp User Manual v1 0 follow that may help you assemble the components to the PC board IC sockets should be used for all integrated circuits Single in line 0 1 spaced female sockets are used throughout the PC board to provide patchable access between the various signals and the additional components that you will plug int
6. on the bottom side of the board from from the pad to the grounded side of the trim potentiometer next to it USING THE QuickieLab The QuickieLab is first and foremost based on the BASIC Stamp The vendor of this ingenious device Parallax com provides an excellent development suite to support hobbyists in their programming and use of the Stamp When you purchase the microcontroller from Parallax you can request a CD ROM containing software for your PC that allows you to create modify your BASIC programs and download them to the Stamp ontained on the QuickieLab Otherwise all software contained on the CD ROM is also available for free download from their Stamp web pages at www parallax com Parallax PBASIC commands are tailored to real time control of simple hardware devices and there are many useful extensions to the language which are of great value to homebrewers The CD ROM also contains many sample programs illustrating basic operation of the commands and chip features You can quickly test your assembled QuickieLab by running a BASIC software program provided on the project website This QuickieLab Monitor Program exercises most of the board s features and customizing the Monitor program is an excellent starting point for you in making your own programs and experiments A Users Manual is provided in PDF format on the Parallax CD to guide first time users through typical BASIC program creation and debug sessions A com
7. part of the built in arsenal of components The I O Expander interfaces to the ubiquitous ADC0831 chip and the BASIC program in the Stamp can issue an ADC command instructing the analog conversion to be done The 8 bit value is then returned to the Stamp controller for possible computation and display Keypad Yet another important I O component contained in the I O Expander chip is that of the software driver and hardware interface to a keypad Useful for numeric and command entry this 4 row x 3 column matrix keypad is constantly scanned by the SX controller Whenever a keypress is detected a message is sent to the main BASIC program in the STAMP controller and specific action can be taken In this way the programmer i e N2CX with his application note software or you with your own software experiment may input data set frequencies to be later output etc Digital Potentiometer The final built in I O device controlled by the I O Expander is a non volatile digital potentiometer This device is essentially an electronic pot that can be adjusted under program control to move its wiper to be at any of 100 positions If for example this digital pot were jumpered into the feedback loop of an op amp on the plugboard your BASIC Stamp program could output a command to the I O controller to adjust the pot up or down to change gain of the amplifier stage This is a pretty neat capability to have in our experimenter s platform
8. the function provided in this versatile controller Serial LCD Display Driver The SX 28 accepts serial commands from the BASIC Stamp to display the specified ASCII character directly or a command character to control the cursor position and other LCD functions like clear display and scroll control The SX 28 duplicates the simple command structure found in other serial LCD controllers allowing the QuickieLab programmer i e you to easily display messages to the LCD display You can clear the display home the cursor control scrolling and blinking and simply display characters all by means of a serial output command from the BASIC Stamp software you ve written Frequency Counter Another unique feature of this I O Expander chip is its ability to measure frequency Since this fast SX processor is sitting idle most of the time waiting to be commanded by the Stamp to display characters I dropped Copyright 2003 G Heron N2APB in a tried and true software routine that samples the signal on the RTCC pin and determines its frequency Thus when the Stamp commands a frequency measurement the SX processor sends back certain data that represents the frequency of the input signal up to 30 MHz This is a pretty useful feature for a QuickieLab such as ours A to D Converter Since it is important in most of our ham experiments to read an analog voltage of some sort we felt it would great to add a simple 8 bit A D converter as
9. e supply at the time of the kit design However from time to time specific discount surplus parts may be temporarily unavailable and a homebrewer may need to use displays from other manufacturers In general any 2x16 or 2x20 character LCD that uses the HD44780 controller and has a 4 bit interface available will functionally work with the QuickieLab board and software Other manufacturers display form factors will likely be different and you will need to make up a simple 10 wire harness to connect the display to the appropriate pads on the board connector J13 Just adapt your specific display to the QuickieLab and you ll be in business Voltage Regulator VR1 If you use the heatsink recommended it would be good to drill a 1 8 hole at the marked location and screw the heatsink and VRI combination to the pc board You should also use thermal grease between VR1 and the heatsink as this will ensure a good thermal connection and give you the widest safety factor for power dissipation Copyright 2003 G Heron N2APB Potentiometer R10 You can use any mini pot for this component Just glue it to the board and wire its three connections to the respective pads nearby the component ERRATA 1 J12 was inadvertently used as the reference designator for two connectors the Keypad and the Digital Pot 2 Pin 1 of the LCD connector J13 was inadvertently left ungrounded You should ground this square pad by placing a short jumper
10. ieLab Assembly amp User Manual v1 0 bed for experimentation measurement and simple control Further we thought it would be great if this experimenters platform were tightly coupled with the string of N2CX Quickies presented in each issue of QQ magazine This would provide Joe with a computing module to help illustrate his points and the readers with a quick and easy way to reproduce the Quickie material Hence the name of this project was born the QuickieLab Copyright 2003 G Heron N2APB THE BASIC STAMP The QuickieLab is a 4 5 x 6 printed circuit board with keypad LCD switch input and LED output capabilities built around the popular BASIC Stamp processor from Parallax inc The Stamp was selected because of its easy to program BASIC language and its simple hardware interface just connect 5V to this Stamp chip and you can download a BASIC program from your PC to wiggle the output pins and read the input pins as desired Readers wishing to follow along with N2CX and his BASIC language experiments could certainly purchase one of the many fine Stamp based experimentation boards from Parallax com and have a ready to go hardware platform with most of the capabilities described here However one could save quite a few pennies by building the QuickieLab from the plans in this article and end up with a more capable platform that is specifically geared to the Joe s Quickie experiments coming in future installments
11. igi Key GH5001 ND Plugboard Radio Shack 276 175 RS 232 DB9F connector J5 D style Jameco 104951 Coaxial power connector 2 1mm P3 Mouser 163 5004 BNC jacks J8 J9 Mouser 523 31 5538 10 RFX Voltage regulator 1A 5V VR1 Mouser 511 L7805 ABV Heatsink Mouser 532 577102B00 Pushbutton 4 PB1 2 3 4 Digi Key P8075SCT ND SIP sockets J2 3 4 6 7 10 11 12 Mouser 517 974 01 36 Pinheader 2x12 pinheader P1 Mouser 517 6121TN Jumper shunts 16 0 1 Mouser 571 3828155 Speaker 32 ohm Mouser 65 AT 42 or RS p n 273 0093 Transistor 2N4401 transistor Q1 Mouser 512 2N4401 LED 3 Digi Key 160 1104 ND Capacitor 4 7pF disc Mouser Capacitor 0022uF disc Mouser Capacitor 1uF mono Future Active SR215E104MAA Capacitor 1uF electrolytic Mouser 140 XRL50V1 0 Capacitor 10uF electrolytic Mouser 140 XRL16V10 IC socket 2 8 pin Mouser 575 193308 IC socket 24 pin Mouser 575 193624 IC socket 28 pin Mouser 575 193328 Potentiometer 10K ohm Mouser 31CW401 or 317 2090 10K Trim Pot 10K ohm Mouser 72 T93XA 10K Resistor 220 ohm Mouser 291 220 Resistor 470 ohm resistors 3 Mouser 291 470 16264 Copyright 2003 G Heron N2APB Resistor 1 5K ohm Mouser 291 1 5K Resistor 2K ohm Mouser 291 2K Resistor 10K ohm Mouser 291 10K Resistor 100K ohm Mouser 291 100K NOTES 1 The QuickieLab was designed by George Heron N2APB
12. n audio tone that can range from 200 Hz up to 10 KHz Can t you just imagine a an upcoming Joe s Quickie application using this speaker to produce an audio dip when measuring SWR Each of these built in I O devices is wired to a specific I O pin of the Stamp through pinheader P1 When the corresponding pins of P1 are jumpered with configuration blocks the respective signals are wired directly to I O pins on the Stamp In this way you could easily configure the QuickieLab to use its built in components for experiments without necessarily using additional components on the plugboard When a given built in I O device is not needed for the current experiment its pins on P1 can be left open and the Stamp s I O pin on J10 may be jumpered over to something else on the plugboard 1 0 EXPANDER Perhaps the most attractive feature of the QuickieLab as compared to commercially available Stamp boards is the customdesigned I O expansion processor U2 Readers of the Digital QRP Homebrewing column in QQ will recognize the SX 28 microcontroller used for I O expansion here as also being used in the PSK31 Audio Beacon and Badger smartbadge projects This time I programmed the SX 28 to enhance the QuickieLab by having it serve as an intermediate processor that helps in the input and output of some additional built in components The IOX project website provides complete details on interfacing and using the I O Expander but here s a quick overview of
13. o the experimenter s plugboard These female sockets are also used to connect the LCD and keypad modules which are held up off the board with standoffs and plug into connectors on the PC board to facilitate easy access to components beneath them during the construction and test phases The strips are purchased in 36 or 72 position lengths and must be snipped off to create the individual pieces for each connector When snipping off a length of the strip you will likely lose destroy one position and need to file down the rough end to make it a clean edge Alternatively a fine tooth hobby saw may be used to create the individual pieces without losing a connector position in the process Stamp I O signals socket The socket strip containing the Stamp I O pin signals is located directly to the left of the plugboard to allow the user to easily place a wire jumper from any given BS2 signal to a component on the plugboard Built in I O Header Jumpers placed along a dual row 0 1 pinheader to patch in the built in IO devices located above the plugboard Speaker The thin 16 or 32 ohm speaker is glued to the bottom side of the PC board and its leads are soldered to the noted pads Rubber feet should be attached to the bottom of the PC board to allow it to stand comfortably on your work table when in use LCD The QuickieLab PC board was layed out using a popular 2x16 LCD from BG Micro This part was very inexpensive and in larg
14. plete PBASIC language guide is also in the Users Manual for detailed use as a programming reference With all this neat development stuff provided by Parallax you can easily have your QuickieLab up and running within an hour All you then need to do is download the specialized QuickieLab Application Notes from the project website www njgrp org quickielab send that specific BASIC program to your QuickieLab and you ll be able to keep right in step with N2CX when he comes out with the next Joe s Quickie in the pages of QQ Any convenient source from 9V to 12V may be used to power the QuickieLab The supply current is only about 85ma so even battery operation is feasible LIMITATIONS The BASIC Stamp as a microcontroller and the QuickieLab as an experimenter s platform each has great potential for instruction and utility on your workbench However I d be remiss not to caution readers about some limitations QuickieLab Assembly amp User Manual v1 0 Any implementation of a Stamp microcontroller might be seen as an expensive computing solution The BASIC Stamp starts out at 49 and the other components add up from there A complete QuickieLab might well cost the homebrewer over 100 by the time it s completed But expensive is a relative term and some homebrewers will likely see this investment as valuable in terms of its educational and long time reusable nature The QuickieLab is not a performance oriented or e
15. xtensible microcomputing platform A very limited number of I O pins limits how many hardware components can be connected at one time Further the effective speed of the Stamp is significantly slower than the HC908 Digital Breadboard project or any other native language PIC processor mainly because the Stamp interprets its high level BASIC commands individually at run time greatly slowing down its overall jmputing process In contrast the HC908 Digital Breadboard project is a far better choice for a flexible and dedicated high performance control and measurement piece of equipment for your bench However even with these limitations the QuickieLab is a great educational solution for quick and easy experiments that don t require lots of high speed operations N2CX regularly tells me how utterly cool it is to be able to program an algorithm into the QuickieLab and see immediate results Any way you look at the QuickieLab it s easy to build fun to use and you can bet that we ll be seeing lots of applications for it in future Joe s Quickies And for starters have a go at the Audio Voltmeter application elsewhere in this issue PARTS LIST BASIC Stamp IC U1 www parallax com I O Expander IC U2 Y1 resonator amp PCB NJQRP Club A D converter U3 Digi Key ADC0831CCN ND NV Trim Pot IC U4 Digi Key DS1804 100 ND LCD 16x2 character LCD BG Micro MDL www bgmicro com Keypad 4 row x 3 column D
16. y of them to components placed on the plugboard In this way the components called out in the experiment may be temporarily wired to the Stamp and controlled by the software program For example you could mount a diode resistor and a couple of capacitors on the plugboard jumper the output of that network to the built in A D converter see following section and have yourself a rudimentary but useful RF voltmeter Of course you d have to have the Voltmeter software loaded on the Stamp from the N2CX Quickie website Joe intends on having many such software programs and application notes available for the QuickieLab QuickieLab Assembly amp User Manual v1 0 As mentioned a number of common I O devices are provided on the QuickieLab board for use in the various experiments Three pushbuttons and three LEDs are provided for simple input and output controls and indicators Sometimes the most instructive experiment is to press a button and see a corresponding LED be illuminated under program control A built in potentiometer is provided and is quite useful as a control that delivers a continuously variable 0 255 binary input to the Basic program A program can read the pot and adjust a software algorithm based on the specific setting A simple D to A converter is provided to produce a DC voltage from 0 to 5V for controlling other hardware under software control And lastly a speaker is provided to enable the Basic program to output a
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