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Author: dannystaple

Diff for: content/2018/04/2018-04-06-piwars-fixing-sensors.md

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+---
+title: PiWars 2018 Robot - getting the camera and sensors working again
+date: 2018-04-06
+tags: [robot building, piwars, opencv, electronics, power, raspberry pi robotics project, raspberry pi opencv project, python, raspberry pi camera]
+---
+After changes to the robot hardware, a new software SD card image and lots of work on the robot, I needed to get the camera going again. It seems that the parts I'd not been paying attention to were now broken.
+
+## Getting the camera working
+
+* I need the picamera python library:
+
+```bash
+pip install picamera
+```
+
+* Now try my `skittletrack` code - which has had a tiny bit of python 3 adapting.
+* No module gpiozero - do we really use it? No - removed.
+* We then need the camera enabled:
+
+```log
+picamera.exc.PiCameraError: Camera is not enabled. Try running 'sudo raspi-config' and ensure that the camera has been enabled.
+```
+
+* Tried enabling it in raspi config. Nope. AH - it's not plugged in. Shutdown and fix that.
+
+## After refitting and rebooting
+
+Try again - get it running.
+
+Yes - it works - and tracks!
+
+We have working tracking - for random objects. Need to find HSL values for stuff, but this is a good start.
+
+## Single distance sensor
+
+It looks like this can be done with rpi gpio (as in Piconzero datasheet) or perhaps with gpiozero.
+
+It was a dependency of the `skittlebot` class in the code.
+
+## Multiple sensors
+
+This is going to get interesting. I had a chat with @4tronix on twitter and asked for some ideas for using multiple distance sensors with the PiConZero.
+The PiConZero itself wouldn't be able to, but additional GPIO boards could. So the options are:
+
+* creating a shim to attach to sensors.
+* Finding an IO extender/interceptor board.