Design Evolution

The clock started out as a Christmas project for a Pi Zero I had just received. Having got a lot attention from my original blog post, I decided to work it up to launch as a Kickstarter, essentially to fund a production run of PCB boards. While working the PCB layout for the TF I realised it would be quite easy to iIMG_1751ancorporate the option to run the clock from an Arduino Nano. So spent a bit of time breadboarding it to check there were no problems with the Arduino RTC and display driver libraries, then added a Arduino Nano as an alternative processor option onto the PCB layout.

Finally in the spirit of flexibility I added extra drilling’s so you can, with relative ease also mount a Raspberry Pi A / B onto the back of the TF board and then wire them it in using individual jumpers. The only Pi’s I haven’t  catered for are the very early revisions without any fixing points. These will still drive the board but you will have to figure out your own mounting arrangements.2b cropped

If you want to go the complete DIY route you can find details of the original breadboard version including schematic and simple functional version of the s/w here. Note: –  In working up the design for the Kickstarter I had to make a number of changes to accommodate the Arduino and early Pi boards, as result the software for the DIY version is not fully compatible with the Tempus Fugit PCB and visa versa.

 

 

Software

There are basically 4 variants to the TF software you need to be aware of;

Prototype, this was the initial version written to work with the first ‘breadboard’ TF design, this has more limited functionality and is not compatible with the Kickstarter hardware. It is available together with instructions, on my GitHub site for anyone wanting to build their own wordclock from scratch. This s/w is not maintained and will not work current Raspbian and max7219 library’s, without a bit of updating.

TF Kickstarter rev3, this version was supplied as part of the Kickstarter package and includes support for French and Dutch displays. As of Jan 2018, this version is now considered obsolete and is no longer supported. The background to this is that changes to Raspbian with the 2017-11-29- Kernel Version 4.9 update combined earlier changes to the underlying max7219 library resulted in the rev3 s/w no longer working.

TF Rev 5 s/w, this is the current support version, using Richard Hull’s revised luma.led_matrix library, rather than the earlier and now depreciated pre 2017 max7219 library. This is the version that will be supplied with any TF Wordclock orders from Jan 15th 2018. To upgrade to this from the rev 3 s/w I recommend you start from a clean install of Raspbian and follow the directions in the Rev 8 (or later) TF instructions.

Latin, this is a fork of the earlier TF software and compatible with TF Kickstarter hardware, This s/w is not currently maintained and will not work current Raspbian and max7219 library’s. If you are (or want) to use this, please contact me and I will look at getting it updated to work with the current luma.led_matrix library.

To understand a bit more about the changes in to Max7219 driver library, which has been the primary driver of the changes have a look at Richard Hull’s GitHub site.

Advertisements