simple analog to digital via USB

[cbrooks999]

Hi All;

I need to build or purchase (pre-built preferred) a device that can measure the physical location of the rudder on my boat and make this information available via a USB connection on my laptop. The purpose here is to enhance a home built auto helm.

I can build the mechanics no problem but need assistance with the rest:

Option 1) Be able to measure distance (~1 foot hopefully with up to 1+ mm accuracy) via whatever means (laser? Transducer?) and translate the measurement into any digital form.

Option 2) I can set up a long slide POT (i.e. 100k Ohm) via mechanical means (less accurate but will do) and somehow translate this into a digital measurement read via USB

Any recommendations here? I’d like to keep my costs down if possible. I’m hoping there is a pre-built simple solution such as the magnetometer I used for compass heading.
Any assistance is appreciated.
Thx!

 

[Harald Kapp]

Does it have to be a linear encoder? If the distance travelled is small enough, you could use a cheap digital caliper as posistion sensor and convert the serial data to USB using a standard UART (serial) to USB adapter.

I thought the rudder's position could be taken as a rotary movement. A rotary encoder together with a microcontroller for processing the data and sending it to a PC would be my way of takling this.
Or buy an off the shelf rudder angle sensor.

In both cases some programming on the PC side will be required to make meaningful data from the serial data stream.