Module heartbeat monitor with 15 inputs and LCD

From CaveLab
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This module was part of the rack box project — which was terminated when I moved out of my first apartment.
MSMU2 installed in the Rack box

Every AVR driven module has an output with a pulsating signal called lifesignal. This is connected to MSMU2, if this signal should come to an end MSMU2 will sound a module timeout alarm. The signal needs to be absent for 10 seconds before the alarm sounds.

MSMU2 can monitor 15 modules, a LCD display shows the status:

#n/a means not connected
Ok→21 means ok, and the remaining timeout

If a module should fail MSMU2 will only show the failed module numbers, alarms must be reset manually using a push button.

Video

I/O

Inputs

  • PA2 Module 1
  • PA3 Module 2
  • PC2 Module 3
  • PC3 Module 4
  • PC4 Module 5
  • PC5 Module 6
  • PC6 Module 7
  • PC7 Module 8
  • PD0 Module 9
  • PD1 Module 10
  • PD2 Module 11
  • PD3 Module 12
  • PD4 Module 13
  • PD5 Module 14
  • PD6 Module 15
  • PD7 Reset

Outputs

Connectors

D-Sub 9-pin

  1. 5v
  2. 0v
  3. Reset
  4. Module error LED

D-Sub 15-pin

  • Module 1 → 15

LCD display

12345678
MSMU #2
Running
1  Ok>21
4  #n/a
10 FAIL!
Reset!

Source code

Git-alt-brands.svg
Bascom-AVR source is available in a git repository:
https://github.com/thomasjsn/AVR-Module-heartbeat-monitor-LCD

Gallery

Schematic drawing

Module-heartbeat-monitor-with-lcd-circuit-gypm0g.png

Parts used

Qty. Part
1 × AVR AT90S8515-8PC, DIL-40, 8 MHz, 32 I/Os
1 × Capacitor, aluminium electrolytic, 10 µF, 25V
2 × Capacitor, ceramic, 22 pF, 100V
1 × Capacitor, ceramic, 1 nF, 100V
1 × D-sub soldering cups, 15 pin female
1 × D-sub soldering cups, 9 pin male
1 × DIL socket, 40-pin, 15.24mm
2 × Diode, small signal, 1N4148/Ph
1 × Enclosure, plastic (1591), 120x80x59mm
1 × Fuse 5x20 mm, 500 mA, fast-acting
1 × Fuse holder, open, PCB, 5x20mm
1 × Fuse holder, open, PCB, Protective cover
1 × LCD display, dot matrix, 16x1, LED green
1 × LED 5mm clear, Blue, 4.9V, 20mA, 350mcd, 12°
1 × LED 5mm clear, Green, 2.1V, 20mA, 385mcd, 6°
2 × LED holder 5mm, RTC51, black plastic
2 × Mounting bracket, DIN rail, Metal
1 × Quartz crystal oscillator, 4 MHz
1 × Resistor, carbon film, 0.25W, 120 Ω, 5%
18 × Resistor, carbon film, 0.25W, 330 Ω, 5%
2 × Resistor, carbon film, 0.25W, 4.7 kΩ, 5%
16 × Resistor, carbon film, 0.25W, 10 kΩ, 5%
1 × Switch, push-button, 1-pole, 1A, 50VAC, off-(on)
1 × Switch, toggle, 1-pole, micro, on-on
1 × Transistor, NPN, 100 mA, 45V, 0.5W, BC547B
1 × Trimmer, carbon, 10 kΩ, horizontal