Looking for consultant / please advise on feasibility

Projects General Guidance
1

I have a project that I think may be a good fit for Arduino, and to speed things along I'd be willing to pay someone to help with the development. Is there any good way / suggestions for how I can get connected to a developer community and find someone that might be willing to help me on a contract-for-hire basis?

As a first step, let me describe the basics of what I want to build, and please people chime in and tell me if Arduino is, or is not, a good match for this.

(Note: if I should be posting in a different forum please let me know, and as a newbie I apologize in advance if my description below is poor...)

I want to build a small, cheap device that will have the following characteristics:

  • it has the ability to receive data over a USB connection
  • it has the ability to generate DTMF tones over a speaker
  • it has some ability to store data
  • it has a button that triggers the generation of DTMF tones
  • (optional) it has the ability to receive and decode DTMF tones (by decode, I mean determine the digit an incoming DTMF tone represents)

Basically, the device will be connected to another metering device via USB and will receive and store data from that device. Some time later, the user will push the button and the data will be used to generate a sequence of DTMF tones. The optional part is that it would be nice if the device could receive answering DTMF tones, but if this is not possible or pushes cost to high then its not necessary.

By cheap I mean that I could build these devices in bulk for less than $10 cost of good sold. This would be a commercial project.

Please advise your thoughts. Feel free to contact me directly (either by message or email at dave at dchorton.com) as well.

2

The USB requirement may be the killer here - the Arduino uses a chip to act as USB - serial converter but to use this as a USB master would be non-trivial work. USB is complex. Someone else may be able to advise on how much work and whether the ATmega8U2 can be used for this.

I'm concerned that the task of receiving DTMF tones might be tricky - it should be possible by digital processing of the analog input, but it might be a struggle - as a backup strategy DTMF decoder chips seem to be cheap, but I've found only surface mount ones and they need a 3.58MHz crystal. However they should be easy to interface to. The 8U2 may be enough to do all the application logic - so I think it might be possible to keep parts cost within limit, but that's a mighty tight budget unless you are going to outsource production to China/Taiwan or such.

When you say 'ability to store data' we need to know the amount of data...

I found these 3 to 5V compatible DTMF chips:
decoder: HT9170D-18SOPLF
generator: HT9200A-8SOPLF

3

What type of program will you be using to send data to the Arduino? It might be so that this program will have the ability to send the info through Bluetooth, in which case, the Arduino will be well adequate to receive the info while doing the rest of the code...

Another option (but perhaps a bit more expensive) is using a Wifi shield, and communicate through it...

4

I think the budget says "forget any additional DTMF decoders/WiFi/Ethernet/Bluetooth".
DTMF generation shouldn't be a problem, decode, maybe, using something like Goertzel's algorithm.
As noted, the USB is a bit of a biggy.