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22/11/2020

Battery Charger Discharger Board - WTF ?

 I am currently building an Amateur Radio project that will run off batteries. In order to stop over-discharging that battery I need a controller to cut the power before damage occurs. I wanted something "off-the-shelf" so I bought a  Battery Charger Discharger Board from Ebay.

The instructions are abysmal so I did some testing and managed to figure out how to operate it.


30/10/2020

TimeTools T1000/2 GPS Receiver

I've recently got around to attempting to revive the Time Source project at the London Hackspace that was originally started by russss - a GPS synchronised Lucent/Symmetricom KS-24361 REF-0 reference clock with a 10MHz output (GPSDO). 

Russ was originally using a TimeTools T1000/2 GPS Receiver, a device with very little information available online. I contacted TimeTools for a copy of the manual but got told rather bluntly that it was over 10 years old, no longer supported, and probably didn't work anyway because of the GPS Rollover.

Its a fairly simple device so I figured it wouldn't take too much to figure out, and it turns out it does still work after all. 

TimeTools GPS Reciever
TimeTools GPS Reciever

26/06/2020

Did I have Coronavirus in late January?

I tend to blog about technical topics, but I think this is worth sharing so I'm going to put it here for visibility.

I am starting to suspect I may have had Coronavirus at the very end of January, with symptoms starting around the 29th - Coincidentally the date of the first confirmed cases in the UK.



Weird Red Blotches (26/06/20)


13/06/2020

Flashing the BlitzWolf BW-RC1 with Tasmota

I recently purchased some BlitzWolf BW-RC1 IR Controllers from Banggood to create an IR Blaster between two rooms so I can control my SkyQ box from the bedroom, and also integrate some dumb devices into my home automation system. 

I tend to prefer local control over dodgy servers in the cloud, and as they're ESP8266 based I was going to flash them with Tasmota - an open source project that adds MQTT and other goodies to enable local control.


I was hoping I could use tuya-convert - an awesome tool that fakes part of the Tuya setup process and allows you to flash your own firmware, however it turns out these devices are being shipped with a newer more secured version of firmware that tuya-convert can no longer take advantage of. 


With little documentation online, I took it apart and attempted to flash it via serial. After a few set backs, it became apparent that the serial pins are broken out via the USB connector (N.B, these are the raw serial pins, there is no real USB interface) so flashing is straightforward and doesn't require any soldering.



Note: I only cover  preparing and connecting the device for flashing.  It's assumed that you already know how to flash Tasmota onto a device once it's connected via serial.

23/05/2020

Flashing a HM-10 (CC254X) Bluetooth Module from OSX with an ESP8266 NodeMCU

I recently experimented with a HM-10 Bluetooth Module and Tasmota, and the advice is to flash the module to with a native CC2541 Binary (V707 at the time of writing) to ensure proper operation.

The official Tasmota documentation includes a link to a repo that includes the source for an ESP8266 and a windows application. The sources for OSX but there's no pre-compiled application or instructions. I'm lazy, too lazy to even grab my Windows laptop, so I figured out how to do it with OSX.

HM-10 Bluetooth Module

13/04/2020

The Poor Mans Spectrum Analyser - Spektrum

Over a year ago I bought a Nooelec Ham It Up Plus Upconverter to use as both as an Upconverter and as a wideband noise source, and an RF bridge, also known as a Return Loss or VSWR Bridge, with the intention of combining them with an RTL-SDR to create a poor mans spectrum analyser.

Now we're unable to leave the house for all but "essential trips" I've had more time to play with radio toys so I got the kit out to experiment with, and tested a couple of filters and antennas to see if it was viable.

The VSWR Bridge

05/04/2020

Nooelec Ham It Up Plus - Receiving High Frequency Amateur Radio Using a Laptop

The Nooelec Ham It Up Plus Upconverter takes a radio signal and converts lower frequencies into higher ones. In the case of the Ham It Up, all frequencies are increased by 125MHz, pushing the 0 - 30 MHz Amateur HF bands into the 25MHz - 1750MHz receiver range of an RTL-SDR Software Defined Radio. This allows you to listen to Amateur Radio on your laptop.

It isn't a new device, in fact I've owned it for over a year and not got around to playing with it. But this weekend I had a spare hour to give it a go and was quite surprised when I heard a German station calling CQ.

NooElec Ham It Up Upconverter and Nesdr SMArt RTL-SDR