What is MICO?
MICO is an acronym for Mobile Interactive voice response & COntrol. The word Mico in Portuguese means small monkey. It's pronounced "mee co".
MICO is a shield for Arduino. Arduino is an open-source electronics prototyping platform for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments. Shields are boards that can be plugged on top of the Arduino PCB extending its capabilities. MICO Shield follows the same philosophy as Arduino: open-source and easy to use.
What will MICO do?
MICO connects to a cell phone via audio jack and it has circuits to detect and answer calls. It then uses pre-recorded voice prompts to present information and options to callers, and touch-tone telephone keypad entry to gather responses. Responses can then be used to control lights, motors and other actuators, and get readings of temperature, wind speed, proximity and other sensors. The caller can be just a few feet or hundreds of miles away!
Watch my video for a quick demo.
I am an electrical engineer and I work designing heavy construction machinery. Away from work I enjoy creating electronic projects using Arduino.
The functional block diagram below shows the key blocks that will make up the MICO Shield.
The incoming audio from the handset is amplified and sent to the DTMF decoder IC and also to an Arduino Analog Input (AN IN). The DTMF decoder outputs digital signals to Arduino, letting it know which touch tone key was pressed. The Arduino uses that analog input signal for the call detection logic and also to aid in diagnostics (e.g. detect saturated input of audio signal).
ANSWER/END CALL is emulated by momentarily connecting MIC and GND. This function is used after the Arduino logic detected the phone is ringing and decided to answer the call (the call detection logic may be modified to fit your application)
The JUMPER FOR MIC POLARITY provide you an easy way to select the MIC polarity for your phone. Type 1: Sleeve = ground, Ring 1= mic; Type 2: Sleeve= Mic, Ring 1=ground; If none of these the two popular settings work for you (e.g. some old phones may use TIP for MIC) use should the PCB test points to set the required pin out.
The MIC BIAS VOLTAGE READING is my proud effort to make MICO's setup as easy as as possible. This circuit measures voltage that your cell phone is outputting to bias the MIC line. The provided sample Sketch convert AN IN bits to the measured voltage(Vbias) . If Vbias is positive (e.g. 500mV to 1.5V) you should be all set. If Voltage is negative then reconfigure the polarity jumper. If is voltage is 0, either your phone only momentarily apply the bias to save power OR you may have a phone with different pin out. I'll create setup guide with additional details.
Audio Generation (PWM): the outgoing audio generated by MICO is based on library SimpleSDAudio. The generated audio is coupled into the microphone line (MIC) and also routed to an 3.5mm audio jack which allow you toconnect a standard 32ohm headset and listen in the generated audio.
In addition MICO will have a MicroSD Card slot where audio files are stored, and of course you can use it for either voice or music. Well that's if for key features.
Cell phone requirements: The cell phone you use with MICO must support headsets with Answer/End Call button OR have "Auto Answer Call".
Current Prototype Status
After an initial prototype using only solderless breadboards, I moved the "high-risk" circuits to a perforated breadboard (lower right corner of photo below). That step was to validate schematics.
Before I finalize the circuit schematic and board layout, I want to gather some more data on MicroSD card interfacing with Arduino. I am evaluating the need of a level shifter and a dedicated 3.3v voltage regulator.
Below are two 3D renderings of the MICO Shield. These renderings illustrate the intended shield size and how it will plug into Arduino Uno. The shield perimeter matches Arduino Uno's footprint. Production boards may vary from renderings below, in specific: PCB color, component packaging (DIP vs SOIC), component placement may change.
The money raised will be spent developing, prototyping, and manufacturing MICO. Printed Circuit Boards will be manufactured by OSH Park.
If I highly exceed target funding, PCB manufacturing may move to a higher volume supplier and assembly may be outsourced.
Bonus Feature: if funding exceeds $2000 I will add an NTC Thermistor to all boards so that right off the bat your MICO Shield has temperature sensing capability, just like in the demo video.
EXTRA FEATURE For pledges of $100 or more: Your Voice!
With this feature your MICO will ship out with your voice and not mine as in the demo video. So when you get your MICO and plug it in, you'll hear your own voice saying "Welcome to MICO". Of course you can say whatever welcome message you want (e.g: "Hello Igor"), have someone else's voice, or even record in another language! Isn't that cool?
Here's how it works: I'll send you a text script, your record it using your favorite method (e.g. Windows Sound Recorder, Audacity, ...), and then you will send me the audio file (WAV, MP3 or WMA format). I'll take that audio file and do all necessary conversions and put it in your MICO's MicroSD Card and ship it all to you.
Audio processing will be done my sister-in-law, Tailuana. She's a first-year electrical engineering student and is located in Brazil. She's very excited about taking on this challenge!
(Note: if you don't want this feature I'll ship MICO with the default voice. I'll post instructions on my blog on how you convert the audio files on your own)
Reward #1: Audio Socket Breakout Boards
These handy adapters are a must have if you need to access for audio breadboarding. 3.5mm 4-pole. Of course you can also use them with as 3-pole adapter. They plug right into a standard 0.1" breadboard.
Thank you for reading about MICO! Please spread the word.
Risks and challenges
I have mitigated technical risk of this project by validating its building blocks over the past 2 years. I also validated the final design in a solderless breadboard and then recreated the circuit into a perforated board.Learn about accountability on Kickstarter
- (34 days)