When I set about to design the Verison 2 of the DigiBadge, I had no expectations that this would be the final end-of-the-line product. I expected to learn a lot, to experiment a lot, and to be able to do a lot more. So far, I have exceeded my expectations.
With that in mind, I’m going to go ahead and ‘Announce’ the Version 3 badge. It won’t be as radical a change as the V1 was from the V2, but there will be significant changes. I’ve talked before about adding the SPI Flash card to it, for some persistent data storage. This was initially going to be part of a Version 2+, but things have changed enough to warrant it being called the Version 3.
In addition to the flash memory storage, there will also be a more pins freed up, starting with a change to the control stick input. Initially, I had the control stick running through a bunch of resistors to a single analog input, with each direction being a different resistance. I couldn’t get that working and ended up using five direct inputs instead. The Version 3 will revisit this single analog input, freeing up four other pins. Another pin will be freed by tieing the screen’s Reset pin to the board’s Reset, but then that pin will be immediately taken by the SPI Flash’s CS line. I’ll be trying to break out these pins in the board, but space is limited, so I may not be able to do so.
Speaking of space, though, this leads me to the most significant change. The Version 2 uses two AAA batteries. Why? Well, because 3v is a perfectly acceptable voltage to run pretty much everything at. And it provides decent enough battery life, too. But two AAA batteries are large. Huge, even. They take up about 2/3 of the back of the PCB. I did some thinking, did some checking, and it’s easily affordable to change this.
In series, two batteries provide double the voltage at the same capacity. Two AAA batteries have roughly 1200 mAh of capacity… but so does one, just at 1.5v instead. So, I thought – Maybe I could include a boost regulator. After a bit of searching, it turns out that yes, I can, without much additional expense either. This will do two significant things. One, it’ll provide a nice, solid power state for the board at all times until it dies. This means no more screen dimming. No more worrying about the SD card going below its proper voltage threshold. Two, it’ll allow a lot more of the battery to be used. Currently, the Version 2 badge drops below useful power at about 2.7 volts, or 1.35 volts per cell. Realistically speaking, there’s a TON of power left in the battery – Maybe somewhere between 3-4x as much. The voltage regulator I’m currently looking at goes down to 0.8 volts. While it will use more power, I don’t expect to see much of a difference in expected lifespan.
The Version 3 will fit into the same case as the Version 2, which is why I mentioned those size restraints above. However, I AM working on something for the more adventurous among you: The return of the ‘Hacker’ Badge.
The Hacker Badge will be a significant change from the Version 3’s normal layout. It’ll be larger. A bit larger. It’ll feature the same components, but in a different manner. First, the nav stick will be moved to the front. Second, every pin that can be broken out will. There will be the FTDI connector, along with an ISCP header and headers for the digital pins and analog pins that are free, aproxamately 4-5 of each. It’ll have a different power switch, which will make Alabaster a lot happier in designing a case for it.
There are also a few other devices I’ve been working on, most notably the Super badge which I’ve covered before. I’ve also designed a breakout board for the SPI flash which I’m using, and an I2C controller for a MUX chip, mostly just because I can.
I’ll keep you guys updated with how things go!