Amateur radio, programming, electronics and other musings

I’ve decided the best way to manage this project to to supply everything you need to create your own solution (pcb etc) or provide a kit of bits for you to build yourself.  That way I always know you at least have the right bits.  It’s just not worth the effort providing just the PCB at this point.  I’ll post a high resolution photo so you will know how to place the bits.

I will also be able to supply fully built versions for a small surcharge to cover my time.  All you need to decide is if you wish to have the LEDs and buttons populated as you might wish to use panel mounted buttons and LEDs.

I’ll post again when all the bits have arrived, I’ve properly costed it and have a working example.

Stay tuned.

It’s been a little while since I posted last but it doesn’t mean I’ve not been actively working on the project.  I have drawn out the schematic and PCB using Eagle and will be releasing the files to github ( with the first version of the source code.

I must stress that these have yet to be checked thoroughly so if you fancy double checking it for me I would appreciate.   I plan to get a run of PCBs made in the coming days.

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Tonight I have been experimenting with custom characters on the 4×20 LCD.  I used a custom character when I defined the degree symbol on the Thunderbolt monitor.  As part of that I wanted to be able to have a screen which showed a large UTC clock.  Having decided that I could double the size by using characters covering a 2×2 character space I worked out that HH:MM:SS would occupy 14 chars.  3×3 would just have been possible as that would have taken exactly 20 chars.

My initial research told me that I can store up to 8 custom characters in the LCD with and write them out by referring to the byte address that they had been stored in.  I found a great site for helping out with the design to byte array translation.

I generated 4 custom characters and write them out to produce a zero.  I followed the same pattern to draw out a large one next to the zero.  When I ran the program all I saw was two large ones next to each other.  I found this weird.  I took out the code which wrote out  the second number and reran the program.  I got two ones as before.  I quickly realised that what was happening was as I was reinitialising the custom character it was updating it on the LCD.  This meant I was limited to only being able to display two different large numbers at a time.

Ultimately it means I have to either use a less pretty way of drawing numbers which only use a the 8 character spaces, use a different kind of display or scrap the idea of the large clock.  For the time being I’m going to scrap the idea…. unless someone has some code to donate which produces a nice looking clock.


BeerAs the clock was preparing to chime midnight on New Years Eve, I was preparing a new blog.  I plan to post much more this year than last as there are so many projects which need finishing and writing up.  Watch this space.

Decided to go dry for the month of January.  No real reason other than my wife suggested I couldn’t.

I can drink alcohol again 11 years, 5 months, 21 days, 21 hours, 17 minutes ago

What is NTP?

Categories: Projects, Trimble Thunderbolt Monitor
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Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks developed back in 1985.

NTP provides Coordinated Universal Time (UTC) including scheduled leap second adjustments. No information about time zones or daylight saving time is transmitted; this information is outside its scope and must be obtained separately.

It is usually able to maintain time to within tens of milliseconds over the public Internet and can achieve 1 millisecond accuracy on local area networks under ideal conditions.

The current reference implementation is version 4 (NTPv4), which is a proposed standard as documented in RFC 5905. It succeeds version 3, specified in RFC 1305.

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Netduino Plus 2

Categories: Trimble Thunderbolt Monitor
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Last week I purchased the updated Netduino Plus 2 from Secret Labs.  This version has a network port on it which I have been playing with. It’s given me the nudge I needed to continue with the Trimble Monitor. I have been testing out code to act as a web server and I am currently looking at the spec for NTP (RFC1305). Read more

Report Packet 0x8F-AB Primary Timing Packet

Categories: Trimble Thunderbolt Monitor
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In an earlier post I posted a sample capture from my Trimble to demonstrate the kind of data packets which would need to be interpreted by the software.  I left it for a little while giving any readers the chance to dig into the documentation and decode it themselves.  I received an email from Sam in VKland who managed to do just that and send me the decoded output.  Not sure if Sam is a radio ham but he has already posted some ideas for the future of the project.

0x8F-AB is an automatic output packet which provides time information once per second if enabled with packet 0x8E-A5. GPS week number, GPS time-of-week (TOW), UTC integer offset, time flags, date and time-of-day (TOD) information is provided. This packet can be requested with packet 0x8E-AB.

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