Instructions for building the RLM interface

------- About the construction.

The interface has 6 inports, 16 outports and DTMF decoder.

The 74HC595 is a SHIFTREGISTER with a built in LATCH and is used for controlling the out-ports.
The RLM program clocks serial data to the 74HC595 (DATA, CLOCK, LATCH) who put the data on the parallel ports.

The 74HC151 is a MULTIPLEXER (MUX) and is used for the in-ports.
It has 8 inports and one outport. RLM choose what port to read with a 3-bits parallel binary code.

The 4050 is a buffer. It only stabilizes the data from the LPT-port.

The transistor is used for muting incoming audiosignals to the DTMF-IC while sound is playing from RLM. This is for eliminating false DTMF-detection.

------- About the PCB.

To get the right scale when you make the PCB, just measure the center of the pads at the corners.
The long side is 92mm and the short side is 48mm.

Check these things on the pcb before you start soldering.
Use the picture of the pcb for help.

- That's not any copper track is short circuit.
- That's not any pad isnít frilled.

------- Building.

Start with the 13 jumpers. Use the jumper location picture to check the placement.
Solder the components. I recommend that you start with the IC:s or IC sockets.

- The resistors are soldered in an upright position.
- I recommend that you use IC sockets for the IC:s for easy changing i nessesary.
- Place the IC-circuits in the right direction!

------- Connections

Connecting to the LPT port.

The square pad on the pcb:s lpt-port connector is pin 1
This is a list of how to connect the cable between the PCB and the LPT-port Dsub.

(PCB-LPT) 1-2, 2-3, 3-4, 4-15, 5-7, 6-8, 7-5, 8-6.

------ Troubleshooting

Ground all inports that's not in use (Very important!).
Test the interface with the "I" menu in the RLM-programs setup. From there, you can turn ports on and off and check status on the in-ports.

It is important that the power for the interface coming from a well-filtered source.
A very common problem is that the connection between the interface and the DSUB LPT-port is wrong. Check several times with help from the list above...

Component list for the RLM-interface

The link in some components iare datasheets in Acrobat reader (PDF) format or a link to a page with more information.

Component

no

Placement

ELFA nr.

Description

MT3271

1

U4

73-037-04

DTMF decoder, 8pin, serial

74HC595

2

U2, U3

73-547-80

Shiftregister 8 out

74HC151

1

U5

73-520-24

Multiplexer 8 in

4050

1

U1

73-679-23

Buffer

7805

1

U6

73-095-60

5v Volt reg.

10k

8

R1-6, R10-11

60-106-15

1/4 Watt resistor

1k

1

R9

60-104-90

1/4 Watt resistor

100k

2

R7, R8

64-367-78

Trimpotentiometer

100nF

2

C1, C3

64-226-84

Plastic capacitor

10uF

1

C2

67-003-49

Electrolyte capacitor

4.194Mhz

1

Crytal

74-502-24

X-tal for DTMF-ic

BC547

1

T1

71-072-87

NPN-Transistor

Other

 

 

 

 

D-sub

1

----

44-055-77

For printerport 25-pin

SMT 160-30

2

----

73-088-85

Smarttemp sensor for in- and outdoor temp

 

 

 

 

 

For further details on components, look at: http://www.elfa.se

(c) 1997-2003 SM2UMH Peter Hansson

www: http://metronic.nu/rlm Version 030830