[Unit]
Description=Take a photo and store it ready for uplift to STAN

[Service]
Type=oneshot
User=st33v
# need double quotes to evaluate contents of variable
# Environment="picdate=date +%Y-%m-%d_%H%M"
WorkingDirectory=/home/st33v/pix/
# ExecStart=/bin/echo 
# ExecStart=/opt/vc/bin/raspistill -o /home/st33v/pix/$(eval "echo $(picdate)").jpg
ExecStart=/usr/local/bin/takepix.sh