Joystick controller and Menu system

I purchased a SparkFun Thumb Joystick and have just gotten around to making it work. Works a treat. Gives two analog outputs – one vertical, one horizontal – and a digital output for the stick being depressed like a button.

I’m now creating a library to manage a Menu system using the joystick. The menu system will support 16×2 monochrome parallel LCD screens, like the one I just got working.

The idea being you define different menu levels with options, and child menu items. Selection can be enabled or disabled. Selecting a parent menu item shows the children, moving left and right to highlight an item, depressing the button to select.

This will be a generic menu system that will have inbuilt support for the thumb joystick, but will also allow integration with other input systems.

I’m going to use this on the instructor’s receiver for my D of E group radio tracker project. You’ll be able to monitor multiple teams and use the menu system to show their positions, navigate to them, or view recent status information like location, last report time, distance, speed and so on.

Once I’ve got this working I’ll post a video of an example. Wish me luck!

Recent purchases…

I’ve made a couple of recent purchases after considering the full scope of my project.

Firstly I’ve bought another SparkFun 16×2 LCD module, and this time I won’t ruin it with a soldering iron by accident!!!

This LCD will be used in the D of E supervisor’s receiver module. I’ve also developed a user interface and set of menus so you can navigate through and track multiple teams, find your own position, edit settings, and even navigate to a selected team. (distance, bearing).

In order to drive this though I had to use some sort of interface. Several small buttons seemed a bit fiddly to add to the box, so I’ve opted for a PlayStation controller like Joystick! I can mount this on the project box next to the LCD. If you push this joystick down it also acts like a selection button, so I have left to right, and up to down navigation, and a selection button. Just like a standard modern GPS unit (but at a fraction of the cost).

Interestingly, SparkFun have stopped selling the black project box, now instead selling a clear one. That’s pretty awesome from a show-and-tell perspective! I can now show off the project, and see the power LEDs through the case. No need to drill LED holes that may leak in water.

I’ve also decided to buy a couple of micro SD interface cards – a ArduLogger device from a local supplier, but with the SparkFun OpenLogger software installed. This software is a bit more flexible, allowing you to name multiple files and either replace their content or append new content. Perfect for a receiver tracking multiple teams – you can have a GPX file for each day for each team. Great! I’ll also fit this on the transmitter so I can check the teams actual route later if they go out of signal line of sight. Not that I don’t trust them…

I also decided against bluetooth for a couple of reasons. Firstly, more complexity, space, and power usage for a very limited ‘download’ mode at the end of a walk. Also because I have a whopping 433MHz module already with a high baud rate! May as well re-use that to request and force an upload of an entire set of logs. They’re only a few KB for a day, so won’t take long at all to transmit.

Having two transceivers also brings the tantalising prospect of sending and receiving messages. A future ‘posh’ version of the transmitter may be a bigger battery, and LCD screen, and another joystick – so the team can send progress reports and receive information from their supervisors. E.g. ‘get off the mountain – crazy weather coming!’

I’ve also found a cheap supplier in Singapore for my Arduino Mega boards. More on that in another post. They’re approx GBP 1.80 each! Great if you want to make a lot of modules.

For my next trick I’ll use a Dremel to cut holes in my project case so I can mount the components. More to follow!…