Thanks to Philip Schuster for sharing this project with us! Check out more info here.
If you have read one of my previous blog posts about building a custom Teensy you already know I have been working on a device based on the Teensy design.
Working in my lab with electronics I came across different little challenges once in a while, and noticed that I am missing tools to handle them efficiently. Just a quick list, I am sure you could add various items to the list:
- What is the I2C address of a chip? (yeah, you can work through the Datasheet but the Datasheets I know don’t have an outline topic for this. It’s somewhere hidden deep in text somewhere)
- What is the voltage range of the analog sensor in my current environment (take a photo sensor)?
- Generating PWM or DAC signals
- Does this circuit do anything?
- Does this circuit do anything specific?
- Reading serial output of your Microcontroller/Arduino project
Of course these aren’t any issues that you could not handle with the tools you have. But each of these take time. Checking an IC for it’s I2C address is easy: Connect it to your Arduino Uno, firing up the I2C Scanner sketch and you are good to go. That is 10 minutes minimum finding your Uno, wiring it up, firing Arduino IDE, uploading the sketch. And everything while your workspace is full of components, wires and stuff for the actual project you are working on.
I had been working on wireless sensors for a while that should take the least amount of power possible. You cannot add status LEDs as they draw way too much power. I had those PCBs lying around and had no clue if they do anything. I had to carry my laptop around, connecting it to the PCB to read the serial port to see what it does.
Why, the heck did I learn all that programming and electronics stuff and not using it to solve that issue. I thought of a small, portable device featuring some ports to connect stuff like sensors and other circuits and some menu driven user interface to trigger various modules doing tests, reading data, you get it.
Announcing Little Helper!
I decided to focus on these features for my Little Helper.
- Small (iPod sized)
- Unconnected, i.e. battery powered and rechargeable
- Easy to use User Interface, i.e. TFT screen
- One handed operation
- Support for 3.3V and 5V
- DAC output
- Fast MCU
- Enough RAM for a larger software project
- Arduino compatible
- One button is enough design
Today, when building mobile devices one might think about touch displays. I decided to not use them because they do not allow for good, precise single handed operation, and I think that is an important feature for my Little Helper. The second best interface for small devices is a click wheel. Hundreds of million sold iPod seem to prove that.
This is what I came up with:
Featured Adafruit Products!
PowerBoost 1000 Charger – Rechargeable 5V Lipo USB Boost @ 1A – 1000C: PowerBoost 1000C is the perfect power supply for your portable project! With a built-in load-sharing battery charger circuit, you’ll be able to keep your power-hungry project running even while recharging the battery! This little DC/DC boost converter module can be powered by any 3.7V LiIon/LiPoly battery, and convert the battery output to 5.2V DC for running your 5V projects. Read more.
1.8″ Color TFT LCD display with MicroSD Card Breakout – ST7735R: This lovely little display breakout is the best way to add a small, colorful and bright display to any project. Since the display uses 4-wire SPI to communicate and has its own pixel-addressable frame buffer, it can be used with every kind of microcontroller. Even a very small one with low memory and few pins available! Read more.