It has been a long while since the last post. Amongst other things, the clock has been a work-in-progress. Each time I made some progress, I found some new reason to create a revision. The initial revisions where based on issues and oversights. I am finding that as the project matures, the nature of the … Continue reading Wrapping up the Alarm Clock Project
The Main Board
I created the main board in the same pattern as the original. That made for quite an expensive prototype as there is a lot of empty space. This size is needed to fit the tactile switches in their proper places. Now that I have Revision 2 up and running, a write up of what I have … Continue reading The Main Board
Further testing the μController Display Module
In the last post, I was able to get the μController version of the display module working with a basic test routine that proved that 1. the controller could be programmed and 2. the display was being driven correctly. The next stage is to flesh this out to replicate the MAX2771 API. The purpose here … Continue reading Further testing the μController Display Module
Powering up the μController Display Module
In the last post, I set up the infrastructure on my newly configured PC to make sure that it can at least communicate and program a chip. I needed to do this before jumping in and starting to program the μControll based display module to minimise the number of issues to be encountered. Initial Check … Continue reading Powering up the μController Display Module
Testing the μController Based Display – The Environment
This post is about bringing up the μController based display module for the Clock. In a previous post, I outlined the approach that I would be taking. Since this will be my first attempt at in-board programming on a "real" project, the idea is to take a systematic approach to try to quickly resolve any issues … Continue reading Testing the μController Based Display – The Environment
Alternate Display Driver
The purpose of this entry is to describe the assembly, programming and testing of the alternate Clock Display Module - whereby instead of a dedicated display driver chip, the module will be controlled by its own micro controller. This was created under a separate GitHub branch as UCtl_small. After the relative ease of getting the … Continue reading Alternate Display Driver
MAX7221 Driven Display Module
It is now time to put some theory into action. This entry will talk about the implementation of the clock display module driven by the MAX7221. This chip was selected for the first version of the display module as it provided a one-stop solution for driving seven segment displays. It also SPI compatible and provided some additional features like … Continue reading MAX7221 Driven Display Module
Display Revisited
While waiting for the display board to return from OSHPark, I was also interested in an alternative module. I had mentioned this idea before and it was time to start taking a closer look. For the purpose, I created another branch in GitHub rather than creating a whole new project. The key feature of this … Continue reading Display Revisited
Ohm my!
I have to take a break from the circuits and layouts and go back and verify a couple of calculations. I am referring to the Rset for the MAX7221. I need to be sure that this is going to be correct in relation to the 7-Segment units chosen - and also the discrete LEDs for … Continue reading Ohm my!
Getting Connected
The layout is now done and made the rather gutsy decision to send it off to OSHPark for fabrication. In hindsight, I could have done this cheaper in that I actually opted for a 4 layer board with the ground and power on the inner layers just to get them out of the way. I did … Continue reading Getting Connected
Rebooting Electronics 