12 Silicon chip Australia’s electronics magazine siliconchip.com.au
Comments on DIY weather station idea
In the Mailbag section of the August
2018 issue (page 13), Bruce Pierson
suggests a complete weather station
project.
I agree with him on this; It doesn’t
have to be any harder than most other
electronics projects and would be far
more fun and configurable than buy-
ing a $200 one on eBay.
There are many low-priced rain
gauges, wind speed and direction sen-
sors out there to use without having to
make them. Also, consider the many
varieties of temperature/humidity/
pressure sensors (the BME280 for ex-
ample) along with the trusty DS18B
for remote temperature.
It could be designed with the pos-
sibility of future expansion, eg, addi-
tional displays, data logging, a real-
time clock or GPS time support, remote
sub-stations etc.
There is a project called “Weather-
Duino” which you can find on the
internet. Maybe you could create an
Aussie version of that.
Peter Richardson.
Bribie Island, Qld.
Response: we published a series of
articles on a weather station based
on the WeatherDuino, the Weather-
Duino Pro2 Wireless Weather Station,
in the March-June 2015 issues. See:
siliconchip.com.au/Series/
See also our article on the BMP
and BMP280 (which is similar to the
BME280 which you mentioned), in
the December 2017 issue (siliconchip.
com.au/Article/10909).Building the DDS Signal Generator
I recently build your Micromite
BackPack-based DDS Signal Genera-
tor (April 2017; siliconchip.com.au/
Article/10616).
I have noted the addition of three
RCA connectors in the parts list in er-
rata published in the February 2018 is-
sue. I also noticed that there is a 560W
resistor listed in the parts list which
should be 470W, to match the circuit
and wiring diagrams.
The article mentions the possibili-
ty of substituting BNC connectors for
the specified RCA connectors. I have
chosen this option on my build but I
found it a bit tricky.
Since BNC connectors project fur-
ther into the case than RCA connec-
tors, the top panel with the BackPack
board attached must be rotated 180°
so that the greatest clearance betweenthe board and the connectors can be
achieved.
There is just barely enough room to
clear the components. See the photo
above of my complete unit.
More separation is also required be-
tween the BNC connectors to allow hu-
man fingers to secure the plugs when
in use. To provide the separation, I
mounted the x1 and x0.1 sockets as
far apart as possible, close to the top
panel, while the trigger input connec-
tor is centrally located between these
and towards the bottom of the case.
Note that instead of purchas-
ing ready-made flying leads (Jaycar
WC6026 or Altronics P1017), I pur-
chased Pololu 900 0.1” connector
housings and Pololu 1930 0.1” fe-
male crimp pins from Core Electron-
ics (https://core-electronics.com.au/)
and made the leads to suit. Of course,
to do this one must have a suitable
crimping tool.
Ross Herbert,
Carine, WA.Comments on the January issue
The Editorial Viewpoint in the Jan-
uary 2019 issue of Silicon chip is a
statement of the reality – hobbyists
must be prepared to use tiny surface
mount components. I had to face up
to this fact some years ago and can
hand solder discrete components and
ICs with pin pitches of 0.4mm with-
out problems.
However, DFN and QFN type ICs
presented a problem. My solution was
to glue the IC upside down onto the
PCB and attach wire wrap wire to the
pads in the same manner as the man-
ufacturers connect silicon dies to the
leg pads of an IC package. The only
difference is that I solder the wire to
the pads and they weld the wires to
the die pads.
This method naturally flips the pin
configuration and I have to design my
PCB layout accordingly.
However, this could be used even