Wanted: someone to choose parts and design PCB

[rthorntn]

Hi,

I'm a bit of a newbie thats wants to build something.

I would need somebody to choose the parts, design the board and possibly write the code.

I understand most of what I want to do and I could cobble together lots of breakout boards from aliexpress, code from google and I'm pretty sure it would work (its a PID loop) but I want a professional PCB designed.

Below are my thoughts:

Circular PCB mainboard 20cm diameter with a 50mm hole in the centre (The 48mm [~2mm kerf] centre hole PCB used for the remote rotary encoder and 12 x RGB LED PCB)

Should be designed with serviceability and community open-source manufacture in mind

Extended temperature range

Heat dissipation should be factored in

Power:

Board input is 48V DC, output rails:

48V 10A (heater)
12V 3A (fans and MOSFET drive)
5V or 3.3V 1A (MCU's)

Mainboard has two MCU's

Primary MCU connections:

- Heartbeat output
- Onboard FTDI USB-Serial
- 3 x temperature inputs for thermistor or thermocouple
- 3 x fan outputs, each 12v 1A with speed control and reverse polarity function, onboard motor drivers
- 1 x heater output, onboard power MOSFET, 48v 10A, needs to be spec'd to run for 15 minutes constant
- Remote Rotary encoder and 12 x RGB LED PCB I/O

Secondary MCU connections

- Heartbeat input
- Remote relay board connector 5v logic

The primary MCU's main function is to run a PID loop
The secondary MCU's main function is to power off the system if the primary MCU stops responding (watchdog), maybe it also connected to an onboard thermistor and maybe its operating temperature range is higher than the primary MCU

Being a newbie I have no idea what something like this would cost to design.

Thanks for looking.

Richard

[rx8pilot]

However much you think it will cost.... it will be more. Count on it. Budget for it.

I have seen a lot of projects that are almost finished.... but the money/time dry up before the finish line.

Estimating the cost of a project is easy. Estimating a project accurately is quite difficult.

Short and misplld from my mobile......

[radiokot]

Hi rthorntn.

I wrote in a personal message.

Best Regards,
Alexander

[julianhigginson]

Easily 70 hours.

Probably a fair bit more if you want good technical documentation beyond just the schematic and fabrication/assembly files that allows makers to work on the board, and you want to limit parts selection to through hole or large SMT and avoid modern simple motor control ICs they also limit peak current, etc.

And more again, if you want the firmware polished enough and fully commented for public release and reuse by makers..

I expect you won't need a 2nd microcontroller.  But that depends on more details around what the watchdog behaviour needs to be (and what the device is, in terms of trust the user is exposed to in using it)