Silicon Chip – April 2019

siliconchip.com.au Australia’s electronics magazine April 2019 29

1911118419111184

C

+

CO

N3

CO

N1

2019

1k

W

19111184 RevC

Flipdot Display Driver PCB

12V

GN

D

12V

GN

D

5V^

GN

D D

LT CK

EN

5V^

GN

D D

LT CK

EN

33

Fm

1000 mF

COCON4N4

CO

N2

CO

N2

CON5

CON6

CON7

CON8

ARDUINO UNO,

FREETRONICS ELEVEN

OR COMPAT IBLE

ARDUINO UNO,

FREETRONICS ELEVEN

OR COMPAT IBLE

IO0/RXD

IO1/TXD

IO2/PWM

IO3/PWM

IO5/PWM

IO6/PWM

IO4/PWM

IO7

IO8

IO9/PWM

IO10/SS

IO11/MOSI

IO12/MISO

IO13/SCK

USB TYPEB

MICRO

GND

AREF

SDA

SCL

ADC0

ADC1

ADC2

ADC3

ADCS4/DA

ADCS5/CL

+5V

+5V

GND

GND

VIN

RESET

+3.3V

DC VOLT S

INPUT

1

2

3

4

5

6

ICSP

TO 12V POWER

SUPPLY

• 
  
  
  
  • 
    
  
  
  
  

ÓSC 20 1 9

Parts list (per each 3 x 5 pixel display)

1 black double-sided PCB coded 19111181, 96x58mm (coil board)

1 green double-sided PCB coded 19111184, 96x58mm (driver board)

6 pieces from black PCB coded 19111183, each piece 58x8mm (frame pieces)

15 pieces from black PCB coded 19111182, each piece 19x10mm (pixels)

15 3mm diameter, 1.5mm thick rare earth magnets

4 2x2-way SMD male header [eg, snapped from Altronics P5415]

8 2-way or 4 2x2-way female header sockets

1 9-pin female or male header (CON1,CON3) (see text for details)

Epoxy Resin for gluing magnets into flaps

Semiconductors

2 74HC595 8-bit shift registers, DIP-16 [Altronics Z8924, Jaycar ZC4895]

4 L293D motor driver ICs, DIP-16 [Altronics Z2900, Jaycar ZK8880]

Capacitors & resistors

1 1000μF 16V electrolytic capacitor

1 33μF 6.3V electrolytic capacitor

1 1kW 1/4W 1% metal film resistor

Additional parts

1 12V DC 1.5A power supply (higher current may be needed for multi-character displays)

1 Arduino or Micromite board for control

1 set of jumper leads to connect to microcontroller and power supply

Note: the four PCBs are available as a set at a discounted price (SC4950)

Fig.7: this wiring diagram shows how the Flip-dot Display can be connected to just about any Arduino-compatible board.
The microcontroller needs just four digital outputs to control the display.

between IC1 and IC2. You will need to
lay it over on its side, as the coil PCB
will sit quite close above it.
The 100μF capacitor fits between
IC5 and IC6. It too will need to be laid
over. It does not matter which way the
capacitors are laid as there is ample
space on the PCB.
Fit the female headers next. A good
way to ensure that they are mounted
square and parallel is to push them
over the male header pins on the coil
PCB, and use this as a jig to line them
up with the holes in the driver PCB.
Note that if you fitted the female
headers to the back of the driver board
(which we don’t recommend) then you
could still plug the two boards togeth-
er. But you would need to modify the
software to make it work, since the
connections on CON5-CON8 would
all be reversed. Our code assumes that
these headers are on the same side as
the other components, so the driver
ICs are sandwiched between the two
boards.
Ensure that the two boards sit paral-
lel before soldering the female header
pins. The holes are slightly oversize,
so these pins may need more solder
that you might expect.
An alternative to using the female
headers is to simply solder the male
headers of the coil PCB directly into

the driver PCB. You may prefer this

if you are building a larger display

made of smaller modules, although

it will obviously be harder to repair

any faults.

Finally, you will need a way to con-

nect the driver PCB’s input pins to

a microcontroller and power. There

are two headers for this. CON3 has

two connections for 12V and ground,

while CON1 has six connections for

3.3/5V power, ground and logic-level

control signals.

CON1 and CON3 are spaced 0.1”