Projects/OpenBot
OpenBot is a device that will tweet how long the space is expected to be open for. Use it to announce to members how long the space will be open for. It is currently a mishmash of aluminium and laser cut MDF. The LED has retreated temporarily to the base, but will be returning to prominence soon!
It is inspired by MakeHackVoid's Space Probe and can be found on Twitter as @LHSOpenBot.
Instructions for use
- Turn the knob to indicate the number of hours you think you will be in the space.
- Press the button to tweet this on @LHSOpenBot.
This doesn't replace the "Open to Members" and "Empty" notes on the website but rather complements it. If you are making a special journey and you don't have keyholder access make sure someone will be around when you arrive: use IRC, the mailing list or the Hackphone.
To provide a tidy announcement the time is rounded down to the nearest quarter hour.
About the device
It's under development at the moment - please keep that in mind.
A NodeMCU dev board/ESP8266 runs Arduino code, pushing data over the wifi to [ThingSpeak], which subsequently tweets for us. The number selected on the knob and the estimated time of closing is stored on Thingspeak (web people, ask Aidan for an API key if you want it.)
NTP
At boot and every 720 minutes thereafter the time is updated from one of two NTP servers. The on-board oscillator is accurate enough to stay reasonably in sync over this period of time, after all it's not that important the time is that precise. In the event that synchronisation with NTP services cannot occur but the device can still connect to ThingSpeak and thus tweet, messages will be appended with #ntpfailure to prompt investigation.
The two services are at pool.ntp.org.uk and time.nist.gov.
Motorised Potentiometer
Eventually the knob (which is a motorised potentiometer) will slowly tick down as the time goes by. I'm looking for a suitable H-bridge or similar to facilitate this.
