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Hans Middelbeek 

Spare displays for Nokia 3310mobile telephones are offeredcheaply not only by several sur-plus goods outlets but also via

Ebay. A small program allowssuch a display to be controlledfrom a PICAXE micro. ThePICAXE is a PIC-based microcon-troller marketed by RevolutionEducation Ltd. The special loaderutility programmed into the chipallows it to be programmed withuncommon ease.The little system shown here is per-fect for applications like a smalldatalogger with graphic output.Figure 1 lists the connection datafor the display while the actual cir-cuit diagram around a

PICAXE18X is given in Figure 2.Two signal lines, SLCK (clock)and SDA (data) are needed totransfer data to the display.

Besides these two, we also needDC (data/command), CS (chipselect) and RES (reset).

We need to start by telling the dis-play if the information to be sent isdata or a command — a highlevel of DC indicates data, a lowlevel, a command. Next, we pullCS low to select the display.We can then change the value of bit 7 (most significant bit) on theSDA line and change SCK fromlow to high. The display awaitsthis action before it reads in thelevel of SDA.Next, the whole byte is shifted tothe left by one bit position (i.e.,

multiplication by two) and theabove actions are repeated untilall eight bits of the command ordata byte have been conveyed.As shown in the table, only sixcommands are in principle neces-sary to initialise the display. Oncethese have been processed, thedisplay is ready to receive furtherdata. The transmission of data inorder to display pixels follows thesame procedure, eight pixelsbeing packed into one byte.The program written by theauthor for the PICAXE arranges

the initialisation of the display,writes a word on the top line andthen displays a part of asinewave. The program may be

PICAXE controls Nokia 3310 display

1

2

3

4

5

6

7

8

PICAXE

SUB-D9 

OUT0

IC1OUT1

OUT2

OUT3

OUT4

OUT5

OUT6

OUT7

18X

IN0

IN1

IN2

IN6

TXD

RCV

RST

IN7

17

14

18

15

10

11

12

1316

5

6

1

2

3

4

7

8

9

+3V3

       4       k       7

RESET 

+5V

       1       0       k

22k

SCLK

SDA

DC

CS

RES

050200 - 11

  v   i  e  w  e   d  o  n  r  e  a  r

   N  o   k   i  a   3   3   1   0   d   i  s  p   l  a  y

2

3

5

downloaded free of charge fromour website, the file number is050200-11.zip. The included

subroutines speak for themselvesby and large.(050200-1)

Formerly a tobacco tinGünther Kuhnle

Many electronics enthusiasts areat war with mechanical engineer-

ing, and in keeping with the slo-gan ‘if you can’t beat them, jointhem’ we present a quick andeasy method of housing small cir-cuits in an all-metal enclosure.Although the pictures speak forthemselves, some comment maybe useful.The dimensions of the author’sfavourite (empty!) tobacco tins are110 _ 80 _ 26 mm (l _ w _ h).The box itself conveniently holdsthe components or PCB while thelid not only serves as a mountingpanel for controls and connectors,but also as an effective screen. If necessary the project schematicmay be secured to the inside of the lid, and protected with a coat-ing of clear lacquer.

Clearances in the lid should bemarked with a felt pen only, toprevent scratching the paint onthe surface. A piece of wood,

slightly higher than the inside of the box, is used to prevent thedrill bit from wandering around.To make sure the holes becomeround, wood drills should beused instead of spiral ones formetal. Wood drills will not takedamage from the thin sheetmetal, provided you pre-drill eachhole with a 1.5-mm bit.To ensure a constant supply of empty tobacco tins, the authorencourages a friend to keepsmoking his pipe, having con-vinced him that by doing so,many will profit from his personalchoice of tobacco. So far, he hasremained faithful to his favouritebrand.

(050206-1)

1 Connection data

Pin 1 LCDRSTX - REst (2,8 V)

Pin 2 VOUT - DC/DC - DC/DC voltage converter output (0V)

Pin 3 Gnd (0V)

Pin 4 LCDCSX - Chip select input (2,8V)

Pin 5 LCDCDX - Control/display data flag input (2,8V)

Pin 6 SDA - Ser ial data input (0V)

Pin 7 SCLK - Serial clock input (0V)

Pin 8 VBB - Supply voltage (2,8V)

2