Validation of a pressure sensor shoe sole using two StereoPi boards

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Joined: Fri Aug 06, 2021 9:30 am

Validation of a pressure sensor shoe sole using two StereoPi boards

Post by alexandrialeer »


For my project work at the university, I have used the as described in the blog post
described in the blog post. It works very well so far, I use the synchronisation of the boards via the GPIOs. The camera system is supposed to record the gait cycle of a human being in order to compare the data of a pressure sensor shoe sole with the camera images. However, the given c-programme only triggers a photo. My goal is to take several pictures per second to map the gait cycle well. If I change the arguments in the raspistill command as follows:

Code: Select all

execl("/usr/bin/raspistill","/usr/bin/raspistill", "-s", "-t","1000","-tl","0", "-3d", "sbs", "w", "5184", "-h","1944","-o", pattern, NULL);

and then run de c file, 3fps is recorded.
Unfortunately, the problem arises that I can no longer trigger the cameras in the terminal, although -Photo STDIN !\n"- is printed, no new photos are triggered, the same problem when triggering the photos using the Python file for synchronisation.

I guess it's because of the GPIOs, but I don't know enough about them to modify the script accordingly.
I also replaced the raspistill command with the raspivid command, with the aim of recording synchronised videos. But the same problems occur. :roll:

Maybe someone who knows the system better can help me. Thanks in advance ;)

The c-code as file here: ... opi_sync.c
The py-code as file here:

Code: Select all

#!/usr/bin/env python3

# Import libraries
import RPi.GPIO as GPIO

# Config
pin_notation = GPIO.BCM
trigger_pin = 4

# Setup
GPIO.setup(trigger_pin, GPIO.IN)

# Trigger pin 
GPIO.setup(trigger_pin, GPIO.OUT) 
GPIO.output(trigger_pin, GPIO.LOW) 
GPIO.setup(trigger_pin, GPIO.IN) 

# Cleanup at exit 

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