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ASK SILICON CHIP
Got a technical problem? Can’t understand a piece of jargon or some technical principle? Drop us a line
and we’ll answer your question. Send your email to silicon<at>siliconchip.com.au
Dual Battery Lifesaver
mods for 24V
Silicon Chip is a great magazine.
What changes would be necessary to
use the Dual Battery Lifesaver from
the December 2020 issue (siliconchip.
com.au/Article/14673) with a 24V battery? (J. O’G, Allambee, Vic)
• You would need to use a different
regulator as the S-812C33 is only rated
for 16V at its input. The only suitable
regulator we can find in a TO-92 package is the AP7381-33V-A, but it has a
different pinout from the S-812C33. It
could be adapted to the PCB footprint
with a bit of lead-bending.
The capacitor ratings would also
need to be increased to 50V. The Mosfet ratings are 30V, so they should be
just adequate. Other than the above,
you would just need to change the
dividers to suit the higher thresholds.
Isolation transformer
no good for fast signals
In the November 2020 issue (p110),
a reader inquired about “Adjusting
Mosfet dead time with a scope”. Could
this be done by inserting a step-up
transformer in place of the shunt resistor?
Alternatively, could a ferrite clamp
transformer be used to measure the
dead time current magnitude and
shape? The current meter style clamp
I bought at Jaycar has a voltage-to-current conversion table printed on it.
This meter does not seem to be available any more; perhaps you could
publish a project to build one. (N. B.,
Taylors Lakes, Vic)
• A transformer in that role would
affect the measured signal phase, and
would be unlikely to have enough
bandwidth to accurately reproduce
the signal, which has fast rise and
fall times. So a transformer probably
couldn’t be used to measure the Mosfet dead time accurately.
Ferrite current clamp meters have
the same problem, whereas a resistive
shunt does not cause a phase shift and
siliconchip.com.au
will not affect the rise and fall times,
even at low levels. The measurement
limitation then becomes the scope’s
bandwidth and sensitivity, with many
scopes being fast enough and sensitive enough to make this sort of measurement.
As for your idea of a DIY Clamp Meter, we published such an article in the
September 2003 issue (siliconchip.
com.au/Article/3884). That design is
still valid and all the parts used are
still available, although you will have
to find another source of the 50A alligator clip as the original DSE is no
longer around.
Questions about AWA
ribbon mics
I have a pair of AWA ribbon microphones that are identical in every respect to RCA 44BX models, and I’d
like to know if they were made under
licence by AWA or someone else or
just rebadged. I’ve corresponded with
a guy in the USA who reconditions
these; apparently, his father worked
for RCA and designed the 44BX. He’s
fairly sure they’re just rebadged.
I recall them being advertised in
Electronics Australia in the mid-70s
when 4VL was selling off some surplus studio gear. It stuck in my mind
as my brother was an announcer there
around that time.
Years later, a friend told me he
bought them from that ad and subsequently gave them to me. I’ve loaned
them out a couple of times as stage
props, but on both occasions, they
were used as live mics.
My brother worked at QTQ9 for a
period and had their techs check them
out, and they considered they were
still up to broadcast specs.
I have no use for them and would
like them to be used by someone who
does. The price will be enhanced if
someone can confirm that RCA built
them, so I hope someone can fill in the
gaps. (B. M., North Ryde, NSW)
• We don’t know the answer to this,
but maybe one of our readers does.
Australia’s electronics magazine
Using D1 Mini BackPack with 2.8in screen
I happen to have a 2.8-inch TFT
touchscreen on hand, so I am using it
to build the D1 Mini BackPack project
(October 2020; siliconchip.com.au/
Article/14599). I have wired it all up
and loaded the code etc. Only part of
the screen has a display, and the keyboard buttons respond but they are not
aligned. For example, if I press “s” I
get a “c” etc. Are there other software
settings and changes I need to do to
get a 2.8-inch screen working with this
project? (S. O., Sydney, NSW)
• As we said in the article, our software is designed for the 3.5in display,
which uses a different driver and has
a different resolution to the 2.8in display (480x360 compared to 320x240).
If it was simple to make the software work with both displays, we
would have done so, but it is not, and
it will involve more than just changing settings.
The driver and initialisation code
will have to be changed to suit the
ILI9341 controller that is used in the
2.8in display. Also, all the graphics,
touch and user interface will have to
be adjusted to work at the lower display resolution. That means numerous
changes throughout the code.
We are sure that it is possible to get it
to work, but it will involve significant
changes to the demonstration sketch.
D1 Mini BackPack not
showing weather info
I am building the D1 Mini BackPack;
thanks for an interesting project. I have
gone through the software installation,
and everything seemed OK until I got
to the OpenWeather part.
I made a free account and got the
API key straight away. I entered that
into the script and loaded it into the
ESP8266. When I switched it on, the
screen came to life, and I entered my
WiFi info and then selected my location. But all I get on the screen is
my area, WiFi IP address and signal
January 2021 107
strength stating OK (green), plus the
local time. But no weather information
ever comes up.
I am wondering if anybody has had
the same problem. (R. S., Epping, Vic)
• If it is showing the current time,
that means that it is connecting to your
WiFi OK and has internet access. We
don’t know why it isn’t connecting to
OpenWeatherMap. There’s a lot more
information available through the Serial Monitor, so we suggest that you open
that and check what messages appear.
Your API key should be enough for the
weather function to work.
Vintage Radio cabinet
restoration
I always enjoy reading the Vintage
Radio section of your magazine. Associate Professor Graham Parslow and
Ian Batty do a great job presenting the
details of the restoration process. The
October 2020 edition depicts a marvellous 1940 AWA Radiola, and it made
me wonder about how the cabinet is
restored to such fine condition. Have
you ever published details on that subject? (T. V., Ivanhoe East, Vic)
• We do sometimes have descriptions
of cabinet restoration in Vintage Radio articles, but not that often. One
recent example is the article on restoring a 1946 STC model 512 radio in the
August 2017 issue (siliconchip.com.
au/Article/10764), also by Graham
Parslow. That article had around ten
paragraphs describing the cabinet restoration. More recently, there was the
Vogue radio restomod by Fred Lever
(November 2019; siliconchip.com.au/
Article/12101).
Sometimes the cabinet does not require extensive restoration; it might
have been restored before it came into
the writer’s possession. And sometimes they simply don’t cover the restoration in any great detail.
Pocket Oscillator resets
on input selections
I purchased your Shirt Pocket Oscillator kit (September 2020; siliconchip.
com.au/Article/14563) and put it together over a day or two. When I finished it, I powered it up only to be presented with a blank screen. I could see
that the chip was getting power, so I
tried reprogramming it and it came up
with the welcome screen, then 1000
appeared on the screen.
108
Silicon Chip
But when I try to change the frequency or use the rotary encoder,
the ATtiny85 resets and returns to
the welcome screen. The output from
the Oscillator looks OK on my DSO,
as does the signal from the rotary encoder.
Did I receive an ATtiny chip that
wasn’t programmed? Or do I have
something weird going on with my
unit? I have carefully checked my construction and it appears to be all correct. I wonder if you have struck this
problem and if there is an obvious fix
for it. (T. MacC., Bathurst, NSW)
• It does sound like you received
an unprogrammed chip, but we are
mystified how that could happen.
We checked all of our programmed
chips in stock and they appear to all
have been programmed correctly. We
think this was an isolated incident as
we have not received any other similar complaints.
As for it resetting after you have programmed the chip, the designer (Andrew Woodfield) replies:
It is almost certainly due to a failure
to program the fuse bits, and in particular, the high fuse bit 7. If it is possible to verify the chip after programming, then that bit was definitely not
programmed correctly.
In the Pocket Oscillator design, the
RSTDISBL bit must be set to 0. The
default for this fuse bit is 1, in which
case, any high-to-low transition on the
RST pin (pin 1), where the rotary encoder is connected, will reset the chip.
The fix is easy: program the fuse bit
as described in the article, using any
normal Atmel/Microchip programmer such as one of the super cheap
USBASP programmers.
Once this has been done, you can
no longer reprogram the chip because
the chip will not respond to the reset
signal from the programmer at the
start of programming. The only way
to program a chip once it has been
flashed with RSTDISBL=0 (or with an
incorrectly configured clock source)
is to use a high-voltage programmer.
cycle lead-acid battery that cost over
$200, and I want to keep it on float
charge most of the time and use it for
an electric outboard motor.
Would your Universal Battery
Charge Controller (December 2019;
siliconchip.com.au/Article/12159) be
the way to go? I note that you had a
Deep Cycle Charger (November 2004;
siliconchip.com.au/Series/102), but
thought that might be a bit dated by
now. (G. C., Toormina, NSW)
• Yes, the December 2019 Charge Controller is suitable for float charging.
The November 2004 charger would
also work, but you might find it hard
to source some of the parts now.
I recently had a deep-cycle battery
that gets infrequent use, fail while being kept on float charge. That was with
a standard battery charger and a regulator added on to maintain the float
voltage. I have purchased another deep
December 2019; siliconchip.com.au/
Series/339) and testing it set to 0V with
all pots turned low, I measure -0.417V
at the output.
The article says if it is not 0V, to
check for faults and I’m wondering
How to use Silicon
Chip short links
At the bottom of page 13 in your November 2019 issue, there is a reference
to an article numbered 8124. How do
I find this from your home page? (B.
H., Pacific Pines, Qld)
• It took me a while to figure out
which page of which issue you are referring to. I think it is the web link at
the bottom of page 13 in the November 2019 issue (siliconchip.com.au/
Article/8124).
All you need to do is type the link
address (in this case, “siliconchip.
com.au/Article/8124”) into the address bar on a web browser and press
Enter. It will then take you to the appropriate page. The situation is the
same with our short links to external
websites, which are formatted like
siliconchip.com.au/link/abcd
The links will also work with a
www. in front, but we leave that part
out to keep the links as short as possible. That’s also why we don’t prefix
the links with http:// or https://, which
is technically required to make them
proper URLs. But most web browsers
default to assuming the HTTP protocol, so we don’t include that part of
the links either.
Bench supply output
slightly negative
Using Charge Controller sits
I’m at the point of final testing of the
for float charging
45V 8A Linear Power Supply (October-
Australia’s electronics magazine
siliconchip.com.au
where to look. I also think the temperature reading is a couple of degrees
higher than actual and I’m wondering
if there’s a way to calibrate that. (S. B.,
Banyo, Qld)
• Assuming that you haven’t reversed
the output terminals, the schottky diode should clamp any negative voltage at the output near the output terminals (the one that was confusingly
marked D5 or D6 in different places).
A non-zero positive reading could
indicate a circuit fault, but that diode
is the only thing that could cause a
negative voltage to slip through. We
suspect that it will go away once you
complete the calibration.
The displayed temperature simply comes from a table in the file
“thermistor.h”, so to fully recalibrate
the temperature readings, you would
need to alter that table and recompile
the software.
Otherwise, try changing the value
of the 9.1kW resistor between pin 1 of
CON7 and the +12V rail. That will only
allow you to shift the temperature at
one point, so it might become inaccurate in other places, and it might also
affect how the fans respond and the
thermal shutdown point.
Trouble with touchscreen on Arduino
I purchased the PCB to adapt the
3.5in LCD touchscreen to an Arduino
in the May 2019 issue (siliconchip.
com.au/Article/11629) along with an
ILI9488-based 3.5in screen. The graphics test and SPI display demo sketches
work correctly.
However, the SPI touch calibration loads the serial monitor display
correctly, then blanks the screen and
doesn’t respond to serial inputs or
screen touches. Also, the SPI shield
demo with touch failed to verify (compile) giving the error message “cannot
declare variable ‘c’...” from line 11.
All of these sketches place a lot of
technical bookkeeping in the main
program. Any suggestions to get these
programs running would be appreciated. Silicon Chip magazine is always
a great read! (D. H., Nelson, NZ)
• The only difference we can see between our setup and yours is that you
are using the older Arduino 1.6.13,
while we are using 1.8.5. We are sure
that this is the cause of the “cannot
declare variable ‘c’...” error, and probably the other failures as well. Please
siliconchip.com.au
upgrade your Arduino IDE to version
1.8.5 and then try again.
The reason we put everything in the
main program is to make it easier for
people to modify the software and see
how it works.
Wide-range LC Meter
pitfalls
I recently built the Wide Range Arduino based LC meter (June 2018;
siliconchip.com.au/Article/11099). I
am having some difficulty getting it to
work, and wanted to ask if there was
any errata published for this project
which might help me work out what
is wrong. (B. C., UK)
• There are no known problems with
the article or the design, but there are
a few common pitfalls which can prevent it from working, and can be frustrating to track down.
The two biggest problems that we
have seen from constructors are:
1) Using a relay which has a different pinout, coil voltage or integral
diode compared to the one we used.
Partly this is because our suggested
sources (Jaycar/Altronics) theoretically sell only suitable relays of the
type we specified.
Still, other types are available elsewhere, and it is easy to get them mixed
up. Suppliers might sometimes have
12V relays in their 5V bins, so you
need to check!
The usual symptom of incorrect relays is that the display will work, but
the results will be wrong, or the unit
won’t calibrate correctly. If all the relays are heard to be clicking when operating the device, then there’s a good
chance that is not the problem.
2) Variants of the I2C LCD controller
having a different address. The code
notes (at line 14) that the controller
could be in the range 0x20-0x27, but
there are variants which have addresses from 0x38-0x3F.
If the default address of 0x27 doesn’t
work, try changing it to 0x3F. If the
display is not working, there’s a good
chance this is the reason. This was
noted in an erratum that we published
in September 2018.
Any number of other construction
errors could also show either of these
symptoms, but it is worth checking
the above first. Finally, we note that
one constructor reported that the unit
started working after changing the
comparator IC for another one.
Australia’s electronics magazine
Maximite or
Micromite?
I just bought the “Maximite BackPack” and have assembled it and have
tried it on a terminal. It will connect
and give answers to print 1/7 etc and
the LCD screen lights brightly. But it
will not run the OPTION LCD command; it just says “command not recognised”. Can you suggest anything to
help? I thought of reflashing the HEX
file but am not really sure how. (R. M.,
Ilkley, Qld)
• We haven’t published a Maximite
BackPack. Are you sure it is a Maximite and not a Micromite? Please send
us a copy of the terminal text (commands and responses) so that we can
check them. Also send the results of
this command (which prints the software version):
PRINT MM.VER
The Micromite has no OPTION LCD
command, only OPTION LCDPANEL
so perhaps this is the root of your problems. By default, the screen will light
up white if it is not initialised.
If you want to try reflashing the HEX
file, refer to the Microbridge article
from May 2017 (siliconchip.com.au/
Article/10648).
Running SC200
amplifier from ±63V
Can I power the SC200 amplifier
(January-March 2017; siliconchip.
com.au/Series/308) from a ±63V DC
supply? (R. R., Melbourne, Vic)
• We definitely don’t recommend doing that if you are going to drive 4W
speakers, as you are likely to blow
the output transistors at high output
levels.
We still don’t think it’s a great idea
with 8W speakers, but you might get
away with it. Check your speaker impedance curves (if you have access
to them) to verify that their lowest
impedance is not too low at any given frequency (ideally, no lower than
about 6W). Hopefully, that will keep
the output transistors within their safe
operating areas.
You will have to change the 63Vrated capacitors to 80V or 100V types,
as your supply is likely to have peaks
above 63V. We don’t think any of the
other parts would need to change.
So basically, if you are willing to
risk the output transistors and have 8W
January 2021 109
speakers without any very low impedance dips, you could consider trying
it. But we cannot guarantee that it will
work as the design was not verified
with supply voltages above 60V DC.
Speed Controller cuts
out at higher currents
A few months, I built the High Power DC Motor Speed Controller (January
& February 2017; siliconchip.com.au/
Series/309) with some modifications.
I raised the switching frequency because the motor was too noisy.
I am using this controller for one
Minn Kota 12V trolling motor. I have
used the motor on my fishing boat
with this speed controller, and I’m
happy with it.
But I have one problem that I can’t
solve. Without load, I can adjust the
speed from minimum to maximum
without a problem.
When loaded, once the speed potentiometer is halfway and the current reaches around 16A, the motor
suddenly stops for one second and
then runs again, then stops again. If I
reduce the speed a little bit, the motor
runs normally.
When it stops for a fraction of a second, it also lights up the red LED. My
battery is a 100Ah lithium type and can
provide more than 50A without problems. I assumed the back-EMF was the
problem but adjusting the trimmers
does not solve it. (A. D., via email)
• This is probably due to the lowvoltage shutdown setting. At 16A, the
battery voltage drops below the low
voltage threshold, and the voltage increases when the motor is switched
off or the speed is reduced. Adjust
low-voltage threshold trimpot VR3
for a slightly lower cut-out voltage,
so that the battery does not reach the
cut-out voltage during normal operation when charged.
Uses for ‘electronic
transformers’
Has Silicon Chip magazine ever
published any applications for the
ubiquitous electronic transformer? Are
they suitable and safe for inclusion
into various power supply projects?
I have been one of your keen readers for many years; I used to read Electronics Australia since the 1960s and
made many of the kits. (E. U., Castle
Hill, NSW)
110
Silicon Chip
•
We haven’t used the switchmode
12V AC output ‘transformers’ in any
projects (typically used for driving
halogen or LED downlights). However,
we used the older style 12V AC halogen transformers in a battery charger
project in April 2013 (siliconchip.com.
au/Article/3759).
We would not recommend using
the switchmode transformers in this
application, as they were connected
in parallel for more current, and the
electronic versions may be damaged
when paralleled.
Electronic transformers can usually be used as a 12V AC supply. They
may fail or shutdown if connected to
a bridge rectifier and filter capacitor
to derive a DC supply.
They are mainly suitable for the purpose they were designed for, ie, supplying 12V AC to a resistive load such
as for LED lighting.
CDI module needed
for use in jet skis
I want to rebuild some retro 1980s
& 1990s stand-up jet skis with Kawasaki JS550 twin-cylinder, two-stroke
engines.
These all had CDI systems originally, but it is difficult and expensive
to get original parts, so I am thinking
of building replacement CDI systems
for them. As I understand it, they have
a wasted spark arrangement, where
both plugs are both fired every half
revolution.
On the later models, they realised
that a rev limiter was needed for when
the impeller cavitates and the engine
spins on no load, so that would be a
good feature to add.
I am considering your Replacement
CDI Module For Small Petrol Motors
from May 2008 (siliconchip.com.au/
Article/1820), but I see that you have
also published other ignition systems,
including a Multi-Spark CDI in December 2014 & January 2015 (siliconchip.
com.au/Series/279).
Can you recommend which option
is best for me, and what smart/programmable controls could be added
to such as a rev limiter, multi-spark,
timing advance etc.
As the HV coils and CDI were all
sealed inside a single factory original
unit, what is your recommended coil
arrangement? There seem to be several aftermarket twin coils for sale online, but how would I choose? Their
Australia’s electronics magazine
only specifications are primary and
secondary impedance values. (L. C.,
Donvale, Vic)
• The Kawasaki magneto ignition includes a high-voltage generator coil to
produce around 300V to charge the capacitor in the CDI, and another trigger
coil to fire the ignition.
The May 2008 replacement CDI unit
should be suitable. This CDI will work
with many ignition coils, so the choice
is not critical, and ideally, you should
use the two high-tension outputs to
drive both spark plugs.
We don’t recommend that you use
so-called “sports coils” as these can
develop very high voltages and could
break down when used with a CDI.
The primary resistance of the coil
is an indication of whether the coil
is suitable. Choose one rated at 3W or
more (for a 12V coil). That means that
the charged (or saturation) coil current would be less than 5A (assuming a 14.4V supply from the battery).
Many sports coils have a much higher
charging current.
The multi-spark CDI is more for converting a standard ignition that has
conventional triggers such as reluctor,
Hall effect or optical and powered via
a battery supply.
We have published two rev limiter
designs which you could use, one
in April 1999 (siliconchip.com.au/
Article/4589) and one February 2008
(siliconchip.com.au/Article/1753).
Substituting amplifier
output transistors
I am building a pair of 500W Power
Amplifier modules (August-October
1997; siliconchip.com.au/Series/146),
the article specifies 12 MJL21193/4
output transistors. I have been looking around and found the MJL1302/
MJL3281 which have almost identical
specifications.
Their safe operating area (SOA) is
the same, but the 1302/3281 maximum collector voltage is slightly less
at 200V compared to 250V; the maximum collector current is 15A vs 16A.
The gain-bandwidth products of these
transistors are quite different 4MHz
vs 30MHz.
Can I substitute the MJL1302/3281s
or should I spend more and buy the
MJL21193/4? If they can be substituted, are any modifications required? (L.
K., Wanganui, NZ)
continued on page 112
siliconchip.com.au
•
While the MJL21193/94 transistors
from ON Semiconductor are recommended, they are now obsolete and
difficult to get. We recommend the ON
Semiconductor NJW21193/94 transistors instead.
You could use MJL1302/MJL3281.
As you mention, they have a higher
cut off frequency. This might or might
not be a problem.
They may give better performance,
but it’s also possible that the amplifiers
could oscillate. If you find the DC fuses
are blowing for no reason, try increasing the value of the 100pF 500V compensation capacitor. However, as that
value is quite high, it should be OK.
According to the circuit, you need
seven of each type of transistor, regardless of which types you use.
Power supply cable
stripe polarity
I use figure-8 speaker cable (eg,
Jaycar WB1703) in many projects.
Should the black stripe for polarity
identification be used for positive or
negative?
I originally thought black indicates
negative, but then I noticed that most
plugpacks have the striped side of
the wire indicating positive. Now I’m
thinking that as positive is the wire I
want to be identified, perhaps I should
always use the black striped wire for
positive.
I use the wire for motors and Arduino projects, but if anyone was connecting speaker wire to the black and red
terminals on a speaker box, surely the
wire with the black stripe would go to
the black terminal. Is there a standard
for this? (J. B., Benalla, Vic)
•
If you have red and black wires,
then usually red would be positive
and black would be negative. But it’s
a bit more tricky when you have a
stripe. Sometimes you have a white
stripe, sometimes a red stripe and
sometimes a black stripe (and possibly other colours).
Usually, the stripe is used to indicate positive, but that certainly is confusing when the stripe is black.
Ultimately, it doesn’t matter as long
as you are consistent so that there is
no confusion. As you say, plugpacks
tend to use the stripe for positive
(usually a white stripe, though), so
it would make sense to follow that
convention.
Probably the best solution would be
to use Jaycar Cat WH3057, WH3087
or similar cable which has red and
black insulation for the two wires in
the cable.
Flashing lights wanted
for model railway
I am trying to find a railway crossing flashing light kit, or at least a PCB
for it. I am sure I have seen something
like it in past magazine issues. I have
searched your site without success.
Could someone point me in the right
direction? (P. C., via email)
• We published a two-lamp flasher
circuit (January 1998; siliconchip.
com.au/Article/4748). You can download its PCB pattern from the following page: siliconchip.com.au/
Shop/10/2362
Jaycar also sells a kit for that project, Cat KJ8070. This design runs
from 12V and so is suitable for 12V
SC
lamps.
Advertising Index
Altronics...............................89-92
Ampec Technologies................. 19
Dave Thompson...................... 111
Digi-Key Electronics.................... 3
Emona Instruments................. 101
Jaycar............................ IFC,53-60
Keith Rippon Kit Assembly...... 111
LD Electronics......................... 111
LEDsales................................. 111
Microchip Technology.............. IBC
Mouser Electronics...................... 7
Ocean Controls......................... 39
Rohde & Schwarz.................. OBC
SC Micromite BackPack............ 47
Silicon Chip Binders............... 106
Silicon Chip PDFs on USB..... 111
Silicon Chip Shop.................. 100
Silicon Chip Subscriptions....... 88
The Loudspeaker Kit.com......... 99
Tronixlabs................................ 111
Vintage Radio Repairs............ 111
Wagner Electronics..................... 5
Notes & Errata
Balanced Input Attenuator for the USB SuperCodec, November-December 2020: the photo shown halfway down the lefthand column on page 71 of the December 2020 issue, showing the wiring to the power connector, is incorrect. The positive
(red) wire should be shown going to the bottom-most pin in the socket, with the black (negative) wire to the top. Also, in the
circuit diagram on pages 50 & 51 of the November 2020 issue, the centre (ground) pin of CON3 at upper right should only be
connected to the junction of the two zener diodes, the negative end of the 100µF capacitor next to switch S1 and the negative
ends of all relay coils. The junction between this ground and the other grounds in the circuit is on the main SuperCodec board.
Two LED Christmas Stars, November 2020: in the parts lists on page 41, there is no such part as a 75HC595. It should read
74HC595 instead.
D1 Mini LCD BackPack with WiFi, October 2020: in the circuit diagram (Fig.1), the connections to pins 7 & 8 on the LCD
module via CON1 are swapped. The drain of Q1 should go to pin 8 (LED) while pin 7 is the display SCK line and also connects
to pin 10 on the LCD module and on to the D5 pin of MOD1.
The February 2021 issue is due on sale in newsagents by Thursday, January 28th. Expect postal delivery of
subscription copies in Australia between January 27th and February 12th.
112
Silicon Chip
Australia’s electronics magazine
siliconchip.com.au
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