Reference the budget; I expect the devices to cost between $100-$150 in components (per device, not including enclosure) and I am accepting bids on labor for the assembly/software.
If you want to submit a bid just send me an itemized list of the components you would like to use to make this device and an estimation of your labor costs. Please also include an estimation for the cost of the enclosure if you plan to 3D print it, or if you want to use a prefabricated enclosure just include that in the item list.
If someone sends me a quote I agree with we'll make a deal and start working.
@cedarlakeinstruments
No, it doesn't have to be 3D printed; I looked at the enclosure you linked to and it looks great! It would be perfect for this project. I tried to call one of their distributors to get a price quote per unit but I am waiting to hear back from them.
Reference the software I hoped it wouldn't be so difficult... as an alternative maybe it would be easier to use the onboard real-time clock you suggested; the on/off switch could turn the unit off completely and when turned on the timer restarts at 0 hours 59 min 55 seconds; so you could effectively sync the watches by turning them on at the same time?