Door control system/Logbook

See also http://github.com/londonhackspace/Doorbot/commits/master

2010-09-29

Operator: Solexious

• Worked out why avrdude stopped working - Mark fixed Doorbot to keep the serial port open!
• Wired the door bell up

2010-09-28

Operator: Artag

• 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:
  • See whether PWM/AC requires less current to trigger the solenoid
  • 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)

2010-09-27

Operator: Mark

Problem 1

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)

Tried:

• 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.

Workaround:

• Open serial port on boot
• Hope it doesn't restart

To try:

• 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)

Problem 2

• Chocolate block "plug" is loose, sometimes causing loss of power at slightest touch

To try:

• Replace with header/plugs (we'll try a D-type on Tuesday)

Fixed by Artag

Problem 3

• Flashing arduino has stopped working (stk500v1: no response)

To try:

• Another arduinio (Solexious will bring one on Tuesday)

This was because doorbot had the serial port open

Problem 4

• Rootfs went away at 4:04am

• This might have been the sensitive chocblock again.