Re: IR detector system, biasing of photo diode

On Mon, 28 Oct 2024 11:11:38 +0100, Klaus Vestergaard Kragelund
<klauskvik@hotmail.com> wrote:

On 27-10-2024 18:56, john larkin wrote:

On Sun, 27 Oct 2024 09:03:20 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
 

On a sunny day (Sun, 27 Oct 2024 02:19:14 +0200) it happened Klaus Vestergaard
Kragelund <klauskvik@hotmail.com> wrote in <vfk0u0$3u9en$1@dont-email.me>:
>

Hi
>
I am working on an IR detector that will guide a robot into a docking
station.
>
A IR transmitter on the docking station transmits a beam, and 2 IR
detectors on the robot detects the beam and lets the robot navigate
towards the target. The working distance is a couple of meters.
>
I need it to be insensitive to ambient light/sunlight.

>
>
I use a cheap camera module to track a light source in H and V direction, and just a simple Microchip PIC : for processing
It can, with some added code, track object forms too, like a cross or maybe a big character.
panteltje.nl/pub/horizontal_IR_target_tracking_4686.avi
those camara modulea are IR sensitive to some extend, sometimes you can remove the IR filter from such modules.
It may be a bit of overkill for your application, but OTOH it can do a lot more.
Mainly designed to detect and follow jet exhaust..
You could uee utrasonics too, maybe even simpler, no sun problem, like a bat.
Cheap electret mikes? or modify some ebay 1 dolalr distance sensors...
can be used for anti-collision too.
>
>

 
Right. A sonic scheme could measure the phase between two mikes to
determine the direction of the source with high resolution. That could
be an analog multiplier or a bit of code. The amplitudes would be
useful too.
 
One could compute direction, distance, and velocity almost for free.
 
No problem with sunlight!
 

Could also be done with a chirp and auto-correlation, although this does
not use the phase, but a beacon reference instead

Could that tell the direction of the mother ship?

Three or four omni mems microphones could tell the robot which
direction to go with full 360 degree coverage.

Maybe even estimate range.