Uri_ba's pit Weekly Updates

Weekly Update – 2015/07/16

After a long long time, I figured it’s as good as any time to say a little on where I’m going in the near future.

  1. I need a new caution panel to work with I2C, I’m also switching from “source” to “Sink” si I’ll need to rewire the entire caution panel. so i’m in the process of figure out how is the best way to do it (and make it better) – either way, it’s about 8 hours of hand wiring I’m not looking forward for.

  2. once I get the CP done, I’ll need to adjust my DEDuino code, and I’ll be releasing it. the i2c code is already available in the git (1.2.0 – alpha 2). I’m looking forward for 1.2.0

  3. ICP – it’s really, really overdue. it seems that 90% of the time my hand touches the mouse it’s for the ICP.  I have a unique opportunity with the ICP, I’ll update on that when I can.  but it will be another project starring the Arduino Pro-micro and the LUFA library 🙂

Uri_ba's pit

Solving my light Issues – initial thoughts

After trying to solve the light issues – I’ve decided to step back and look at the situation from another angle.

I have 4 OLED screens to drive – DED, PFL, CMDS and FFI
they are all using SPI – which means I’m low on I/O pins on Uno and Micro because of the need for CS for each screen.

My light situation is somewhat limited due to the same issue – If I go via SPI, I’ll need another CS pin for every device – and I’ll need to work around my issues with multiple SPI devices.

the Other option is keep the SPI for the OLEDs and swap all the lights to use I2C I/O expenders this will pretty much allow me to wire up everything and power it all via a single Arduino Due (due to the faster CPU and no memory issues). it will also allow me to overcome the issue I had with 3.3V logic on a 5V bus I have with the Due.

Uri_ba's pit

Caution panel – tech post

Now that we have seen the Caution panel at work,
Let’s take a step back and have a look at the technical aspect of it.

This post will have some code samples and inner workings – so feel free to move on if that doesn’t interest you.

Uri_ba's pit

Caution Panel – finishing up and testing

I’ve had some time this week to finish up soldering the caution panel and control board, wiring the control board was a bit tricky, the control panel is reversed compared to the caution panel itself,  and then I need to wire the whole thing backwards, which flips it again…

After finishing up the Caution panel, I’ve started by soldering the Shift registers outputs to the connectors

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Once this is done, I started wiring the chips themselves,
Each chip needs to have 5V, GND, CLK and LATCH, OE (Output Enable) tied low RES pulled high. And all of them need to have Serial Data chained in the correct order between all the chips. and of course tie everything into the correct position on the connector – (hoping not to mess things up).

I’ve used my control PCB eagle board design as reference with the schematics – I still hope I haven’t messed up too badly – But I’ll only know that when the boards will come in from china.

Now let’s look at how the Boards integrate with the rest of the project

Uri_ba's pit

Caution Panel – Initial Design and soldering

I’ll start with an apology – I’ve been working on prototyping for this for over a week, And I’ve never too a video or a photo of the prototype working on the breadboard. So this post would be somewhat less illustrated then I would have wanted. sorry 🙁

I’ve decided to take the Indexer design concept and use the Shift register chip’s ability to be chained as a way to drive the Cation panel.

F-16 caution panel is made up of 4 rows of 8 lamps – classic for 8bit shift register, I just need to chain 4 of them and presto – the entire caution panel on 3 pins using SPI (CS, SCK and MOSI – where SCK and MOSI are shared among all the other devices anyway).

We’ll start by looking at the Caution panel structure itself.