Over the past few weeks I have been developing a module which will add 32 digital outputs to the Netduino GO!. I have also been writing about it. Yesterday saw the first board assembled and tested, and here it is:
CompletedBoard.jpg 107.32KB 45 downloads
The blog post which discusses the project can be found here. The first post and summary is as follows:
This series of posts will examine the activities required to take the concept of a module for the Netduino GO! through to production.
A simple project will allow the series of posts to concentrate on the principles required for the production of a Netduino GO! module without being too distracted by the functional aspects of the module. The following project definition should meet this brief:
- Provide 16 or more digital outputs
- Work with the Netduino GO!
- Low cost manufacture
- Use simple tried and tested components/techniques
Meeting the Objectives
As you can no doubt see, this is a reasonably simple project and with the exception of cost, we should have no major problems reaching the objectives. The most obvious solution to this problem is to look at using 74HC595 serial to parallel chips. These are cheap components and the techniques needed to solve this type of problem are tried and tested. The project definition looks like the counting example which is discussed in the Counting Using 74HC595 Shift Registers post with the addition of the Netduino Go! functionality.
Initial assessment of the project indicates that the following steps are required in order to take the project from concept to manufacture:
- Build a hardware prototype using the STM8S103F3 to control two shift registers. This will have some form of visual output to prove that we can control the digital lines (probably some LEDs)
- Write the software for the STM8S which will control the output of the 74HC595 chips
- Generate the schematic for the board
- Layout a prototype board and send to manufacture
- Write the software for the Netduino GO! while waiting for the manufactured boards to turn up
- Assemble a prototype on one of the prototype boards
All of the work is open source so please feel free to use it in your own projects. If you do find the work useful then please drop me a line as I'm always interested in how this work is being used.