Door control system/Logbook
All changes/problems reported with the door entry system.
People are reporting the solenoid not triggering properly. This could be the bolt getting caught against the strike plate, so will test tonight.
- Doorbot died at 10:04. Apparently shorting the pins wasn't it.
- Swapped out the hub with Oni's. It's much nicer, so we should try to find another similar.
- At Jonty's suggestion, swapped out Bifferboard for his spare
- While doing this, we suddenly realised what might have been causing all the problems: the tape beneath the bifferboard had been scraped away by the pins, so they were touching metal case. This explains all the random failure issues below.
- We've put it in its own plastic case
- noticed doorbot & door not working
- as per instructions form irc power cycled the usb hub and bifferboard
- door now working.
- the door stopper needs a big arrow or something, it's easy to miss it and that it's down which makes the door hard to close
- the speaker wires need a better way to get out of the door bot box, as the case is opened and closed it will damage the wires.
- Rootfs went away at 10:30 when samthetechie tried to enter the space. Bifferboard restarted, but didn't boot.
- Reboot of usb hub fixed biffer booting
The USB hub has been unplugged from its own power supply, in the hope that this will let the bifferboard reset the USB drive on failure.Left plugged in, because the reader seems to fail.
- maybe we should power it off the main 5V supply, but arrange to switch it off when USB power goes away. Then it would reset with the bifferboard.
- Phase 1 of the doorbell completed
- Arduino sends a 1 over serial when the door bell is pressed
- LED lights green during solenoid pulse
- Red/Green LED can be controlled by sending numbers to the arduino
- 2 Green on
- 3 Green off
- 4 Red on
- 5 Red off
- There is also a speaker in the doorbell, this is not yet implemented
- Worked out why avrdude stopped working - Mark fixed Doorbot to keep the serial port open!
- Wired the door bell up
Operator: Artag (write-up by Mark)
- Replaced the chocblock with a lovely 25 pin D-Type connector, with soldered joints and heat-shrink.
- Started testing on the scope, but couldn't find a suitable way of using the trigger feature.
- Suggestions for improvements:
10:16:40 < artag> russss: re your query on the doorbot solenoid driver, I was thinking that if we replaced the relay with opto+fet, we could drive the solenoid with chopped dc or even ac (h-bridge drive). Because of the inductance, this might turn out to be significantly less current than 12V dc.
- See whether the 5v supply is having difficulty when the reader is powered
- If so, isolate it and use a hefty capacitor to keep that going (rather than supporting the solenoid)
Identified by Solexious at the weekend
Arduino resets on serial open() from bifferboard
- Arduino flashes digital outputs high on reset
- Digital output flashing high triggers door open (this seems to be getting worse over time)
- Disabling DTS (didn't work)
- Pull-down resistor (10k to 1k)
- Physical reset button on arduino (it also makes the pins flash)
- 120 ohm resistor between 5V and RSET on arduino - works :D
- The board no longer flashes the outputs on boot, but still does when the reset button is pressed.
- Open serial port on boot
- Hope it doesn't restart
- Check voltage during boot, so see whether either line is spiking
- Replace diode on solenoid
- Resistors to reduce sensitivity of darlington
- Use a capacitor to smooth over the reset pulse, requiring > 1 second to trigger relay
- Rebuild darlington/relay board
- Use a solid state relay (no darlington required)
- Chocolate block "plug" is loose, sometimes causing loss of power at slightest touch
- Replace with header/plugs (we'll try a D-type on Tuesday)
Fixed by Artag
- Flashing arduino has stopped working (stk500v1: no response)
- Another arduinio (Solexious will bring one on Tuesday)
This was because doorbot had the serial port open
- Rootfs went away at 4:04am
- This might have been the sensitive chocblock again, as there were people in the space.
- Progressive failure overnight before Sunday of the Arduino talk - very bad. After investigation it was found that the original alarm charger was outputting 6v, so the Nneil donated a wall charger to replace it.
- Numerous bifferboards were destroyed by cigarette lighter regulators which spontaneously become zero ohm resistors when a large (> 0.6A) current is pulled through them.
- The original spec for a 7805 did not take into account the amount of current passed. 7V * 0.8A = a small radiator.
- The original transistors we tried were not enough to trigger the relay, so were replaced with Darlingtons.