Lost.In.Spacebar

Yes Yes. I should stop making changes, but this time, I have a reason. Time Machine 1.0 did not really take into account the battery I was going to use. Adding a battery underneath increased thickness. The battery I was looking at was bigger than the board anyway. Things didn’t really make sense.

So here is Time Machine 2.0 (WIP – still routing):

In order to not make the same mistakes I’ve made before, I started Version 2.0 with something to model it after. Given the number of sensors and the LCD screen, I wasn’t going to model it after a Skagen or something exotic. Something more… nerdy.

Perfect. The classic Casio calculator watch. This thing measures about 42mm x 34mm x 9mm. It is fairly comfortable on my average sized wrist. The current design of the board will fit within these dimensions (including enclosure). Time Machine, however, trades sweet sweet algebra for other useful features like notifications and sensor fusion.

Features

•  0.96″ OLED Color Screen with a 96×64 resolution.
• 240mAh 3.7V battery – Rechargeable via Micro USB.
• 120MHz STM32F2 with 1MB of flash and 128KB RAM.
• PAN1323 Bluetooth module capable of Bluetooth 2.0 with EDR, Bluetooth 4.0, Bluetooth BLE and ANT.
• MicroSD slot for MicroSD cards for various use cases such as  data logging / application storage etc.
• MicroUSB (yay for standard connectors) for bootloader / data / charging etc.
• MPU-9150 9-axis awesome-o-meter
  • 3-axis Accelerometer (upto +-16G at 1000Hz update rate)
  • 3-axis Gyroscope (upto 2000 deg/sec at 8000Hz update rate)
  • 3-axis Digital Compass (upto +- 1200uT)
• Barometer (50kPa to 150kPa)
• Temperature Sensor
• MEMs Microphone with amplifier
• Speaker (small, but should be fun to play with).
• Buzzer
• Vibration motor
• TCS3472 Ambient color/light sensor
• Infrared transceiver
• Pulse oximetry sensor – this is basically an LED and a photodiode in close proximity.
• RGB notification LED
• 4 user buttons
• Debug / JTAG header for developers who don’t care to use the USB boot loader or just want to do some good ol’ printf debugging.

As with the previous version, this is meant to be for people who want to play with toys / sensors. In that spirit, I aim to make the software and hardware open. For starters, I’m thinking of making this compatible with the Maple IDE so users can easily write code for the watch. For other’s who are more comfortable with GCC and toolchains, I’ll work on a real SDK that works with an RTOS of some sort.

But exposition on the software front will have to wait for another post (partially because I still have to think about what I want to do exactly).

Presenting… IOIOINO. At some point a couple of years ago, Ytai designed the IOIO system and hardware developers with Android phones everywhere rejoiced. One disadvantage at least for some of my hobby projects however, was that the board does not conform to the “standard” Arduino board layout. Therefore, the IOIOINO.

The IOIOINO builds off the IOIO-OTG specifically.

Features

• IS an IOIO-OTG as far as the computer is concerned. When plugged in, this board shows up no different. 
• GPIOs are laid out in Arduino layout.
• All pins on the digital side are PWM capable.
• All pins on the digital side have servo-style breakouts.
• Analog pins have voltage dividers. You can solder new registers to change the scaling. This allows monitoring of higher voltages like those from 5V sensors.
• Power jack and 2-pin header to provide more ways to power the board.
• Multiple pins for the power header to allow easy splitting of power to devices.
• Buttons for RESET and BOOT
• 2 User Buttons
• 3 User LEDs

The boards are in and so is the stencil. Hopefully by the end of the weekend, an assembled version will be up. As always, sources and information are available at my Bitbucket.

Work on Sparkplug is slow, but it IS happening. One of the major portions of an Electric Kart is the motor. As I’ve mentioned before, I’m using the ME1003 from Mars motors. To mount the motor to the chassis, I use a combination of a gas motor mount and a custom bracket.

The bracket was designed in Solidworks and was fabricated at Protocase. $150 is perhaps a little expensive, but the quality is great and you get several powder coat colors for free. I chose “Fire Red”. Because really, if you had that option, why would you pick anything else?

One half of the gas motor mount that goes onto the Kart chassis.

The other half that the bracket attaches to. The two parts of the gas motor mount are then screwed together to form a mounting bracket for the motor.

Ah, the LED wall dream. It still lingers.

The column scanning boards do what their name infers. They control power to the columns on the LED wall, while the LED drivers control (through PWM) the R, G, B levels of each row. In this way, the whole wall is controlled with 64 + 32 signals, instead of 64×32 signals. Hurray.

Each board has a shift register and 8 mosfets. The boards are chained to get 64 channels of control.  To control column after column, you simply clock in a 1 into the shift register. Then 0s are clocked in. With each clock, a column turns on. Simples.

As usual the boards and other project related info can be found at https://bitbucket.org/lostinspacebar/lavalamp

April already. Time moves too fast. Next few posts are catch up for not posting in a while.

A while ago, I posted about making a wireless controller using the Wixel. Still doesn’t have batteries in it, but wasn’t very hard. Instead of using the on-board shift register on the NES controller, I decided to use only the Wixel as the logic for the controller.

The Wixel has enough GPIO for all the buttons on the NES controller. It monitors each of these inputs and sends them as bits to the receiving end (another Wixel).

Notice, the wonderfully botched cutting job. Also notice the micro-USB cable. There are no batteries currently, this will have to change soon.

Another item on the TODO list is to actually write a user space driver on the receiving end to convert the data from the Wixel into input messages over USB, a.k.a. make the receiving Wixel look like a game controller to the OS.