Saturday, 7 January 2017

New year - New PCB

Well it was bound to happen some time; the dataflash chip that I use (Adesto AT45DB011D-SSH) has now gone obsolete. This isn't the end of the, or so I thought...

My solution was simply to fit it with the 4 Mbit version, but unfortunately the console reads the chip ID as part of its "security" checks, and if it does not receive the ID for a 1 Mbit chip it ceases communications.

I have been able to source the chip in an alternative UDFN-8 package, so a little work was required to tweak the PCB to accept the new part. This also means that I now have to program the security register with the chip fitted, again no big deal.

The new PCB
Vs the old PCB
This does mean that in the long term I will have to get my head around a way forward. I could simply buy as many chips as I need for the next year, or I could come up with a smarter alternative. Who knows what this year will bring...

Monday, 5 December 2016

*UPDATE* an end of year evolution

A few days ago I posted images of the latest evolution of the BelfryBoy data logger, using a 3d printed cover filler with epoxy to give a nicer finish the the assembly.

the print house that supplied the covers weren't 100% happy with the result so they ran the print again and the results are fantastic! very clean lines, great curves, and dimensionally perfect! Many thanks to 4th Room, St. Anne's!

Here are the results.

Wednesday, 30 November 2016

An end of year evolution

I have been busy this year with moving house, starting a new job and getting my girls settled into a new school, so there hasn't been a great deal of time to work on the BelfryBoy logger.

Despite all this I recently decided to address the aesthetics of the unit, since I have never been completely happy with how the finished logger looks.

I had looked into some sort of low pressure over moulding, like this service from Techsil.

But I decided that in the volume that I make these I couldn't really justify the expense.

I then happened upon the idea of 3d printing a shell that could then be filled with epoxy resin. The design work was all done using onshape, a fantastic cloud based CAD modelling tool, and then printed via 3dhubs, another brilliant online resource.

So here is the first of the finished covered loggers, it's a bit rough round the edges still, but with a little work I hope for a much more professional look.
BelfryBoy Logger with 3d printed cover

A nice little touch

Tuesday, 19 January 2016

If it looks to good to be true.... or Caveat Emptor

Today I had a major upset in the build of this last batch of V2.1 loggers. My usual (reputable) supplier of FT232RL chips was out of stock, so I found a supplier on eBay. Unfortunately the chips were counterfeit.  They looked almost identical, but when plugged into my laptop they reprogrammed themselves, and became non functional.
FT232RL chip fitted

The one on the left is genuine, on the right counterfeit!

It was in the end relatively trivial to edit the driver to function with these loggers, but I'm not willing to ship counterfeit goods to paying customers. This combined with a house move this weekend has severely impacted on my ability to supply all the orders that I received over Christmas. 

Normal service should be resumed in the next week once the new workshop is up and running.

Tuesday, 12 January 2016

"Merry Christmas one and all!"

This Christmas has been very busy in the BelfryBoy workshop, with 30 loggers ordered in the last month, this has taken up a lot of my time and my stock has dwindled rapidly, so I decided to see if the assembly process could be improved.
The last 15 Mk 2.1 boards with their younger brother Mk 2.3

 The main bottleneck has been attaching the USB cable, so this was the obvious place to start, so I have changed the attachment method to use a solderless connector.

 I have also found obtaining the FTDI USB to serial chip problematic, so have changed that as well.

 One final improvement has been the addition of a small handle to make logger removal easier.

 The first boards have arrived and been successfully tested and are now on their way to two lucky weather enthusiasts.

 Thanks everyone for your continued patience if you have ordered one, they will be on their way in the next week.
The latest evolution of the BelfryBoy logger
Close up view

Tuesday, 13 January 2015

how do you solve a problem like a green dot?

Belfryboy Clone green dot logger When the "green dot" problem arose I was at a loss as to how to fix it. But that half the fun.  Then we found the solution. Several in fact. Torkelmj uses a novel method, by programming an Atmel ATtiny microprocessor to behave like a Dataflash chip with the correct security register the Davis console will open its communications port.

But this was not satisfying for me. I wanted to still use the logging abilities. WXforum member Travisc came up with another solution using a PIC to fool the console that then turned itself off and enabled the logging chip once the console was happy.
traviscs solution, very elegant
This was all very well, but still not what I had in mind, but with some collaboration the solution arose. The algorithm used was cracked by comparing genuine logger security registers and the Belfryboy logger was reborn.

All I needed was a way the program the chip.

I initially I started to program the chips using a buspirate in SPI mode and an SO8  ZIF socket. The security register was calculated in Excel and then flashed into the chip. This worked most of the time, but not always.

I tried in vain to write the code to use an arduino board to program the chips, JoeBean beat me to it!

It was then just a case of putting his code on to my fixture and voila, I had a fairly foolproof method of quickly programming the chips.
The finished programming fixture.

Green dot logger page now live

The Stand alone page for the Belfryboy Clone "green dot" logger is now up and running, just hit the tab at the top of the page!

A page for the SHT15 based clone temperature humidity sensor is on it's way too.