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| Mini VFD
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| [[|border|frameless|220px|center]]
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| Primary Contact
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Michael
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| Created
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26/04/2012
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| Completed
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10/12/2014
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| Dormant
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| Version
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| Members
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| Manufacturer
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{{{manufacturer}}}
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| Model
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{{{model}}}
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| Location
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[[{{{location}}}]]
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| GitHub / Repo
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{{{repo}}}
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| Status
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complete
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| Type
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Members Project
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| Live Status
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| QR code
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A small Vacuum Flourescent Display I recovered from the skip at work.
It is housed in a project box with a mains transformer - it use to have a mystery 9-pin serial port input but it wouldn't work until we worked out that it was expecting a 5V TTL serial signal.
The Futaba Corp M202SD08G module is a 20 character x 2 line, 5x8 dot matrix display.
It has a European font with characters in the range from 0x20 (space) through the ASCII range and up to 0xFF with a bunch of Greek and Cyrillic characters.
I've put a Xino into the box and I'm working on something amusing for it to do in the hackspace.
The module has a single 20 pin connector (2x10 0.1" pins) of which we only need connection for +5V, GND, serial data in and a busy line out. The module asserts the busy line when it is working but it is enough to just make short delays in your code!
I have a simple Arduino sketch that just shows each character. It uses NewSoftSerial on pins 2 and 3 as well as regular serial on pins 0 and 1 (on old Arduino0022) just for testing to see if NewSoftSerial is any good.
1 #include <NewSoftSerial.h>
2 #include <icrmacros.h>
3
4 NewSoftSerial mySerial(2, 3);
5 void setup()
6 {
7 Serial.begin(9600);
8 mySerial.begin(9600);
9 }
10
11 int b = 0x20;
12
13 void loop()
14 {
15 Serial.print(b, BYTE);
16 mySerial.print(b, BYTE);
17 delay(100);
18 b++;
19 if(b == 0xff){
20 b = 0x20; // the first char in the VFD table
21 delay(1000);
22 }
23
24 }
The mains transformer in the box is this LASCAR PSU 201 Fixed Voltage Single Rail Power Supply...
Although the unit is useful as a plain serial-driven ASCII display there are some interesting capabilities alluded to in the various datasheets.
The VFD character table includes some programmable characters. I'd like to have a go at this!
There are control sequences to shift the screen and create a scrolling effect.
1 /**
2 * Futaba VFD box Software serial
3 *
4 */
5 #include <SoftwareSerial.h>
6 #include <math.h>
7 // supports 3 major temperature scales
8 enum {
9 T_KELVIN=0,
10 T_CELSIUS,
11 T_FAHRENHEIT
12 };
13
14 // manufacturer data for episco k164 10k thermistor
15 // simply delete this if you don't need it
16 // or use this idea to define your own thermistors
17 #define EPISCO_K164_10k 4300.0f,298.15f,10000.0f // B,T0,R0
18 #define NOTTINGHACK_47K 4090.0f,298.15f,47000.0f // B,T0,R0
19
20 SoftwareSerial mySerial(2, 3); // RX, TX
21
22 void setup()
23 {
24 // Open serial communications and wait for port to open:
25 Serial.begin(9600);
26 while (!Serial) {
27 ; // wait for serial port to connect. Needed for Leonardo only
28 }
29 Serial.println("FutabaBox1 v1.0");
30 // set the data rate for the SoftwareSerial port
31 mySerial.begin(9600);
32 mySerial.println("Hello, world?");
33 }
34
35 void loop() // run over and over
36 {
37 while(Serial.available()){
38 mySerial.write(Serial.read());
39 }
40 updateTemp();
41 delay(1000);
42 }
43
44 void updateTemp(void)
45 {
46 mySerial.print("Temperature: ");
47 delay(10);
48 mySerial.println(Temperature(1,T_CELSIUS,NOTTINGHACK_47K,10000.0f));
49 delay(10);
50 }
51
52 // Temperature function outputs float , the actual
53 // temperature
54 // Temperature function inputs
55 // 1.AnalogInputNumber - analog input to read from
56 // 2.OuputUnit - output in celsius, kelvin or fahrenheit
57 // 3.Thermistor B parameter - found in datasheet
58 // 4.Manufacturer T0 parameter - found in datasheet (kelvin)
59 // 5. Manufacturer R0 parameter - found in datasheet (ohms)
60 // 6. Your balance resistor resistance in ohms
61
62 float Temperature(int AnalogInputNumber,int OutputUnit,float B,float T0,float R0,float R_Balance)
63 {
64 float R,T;
65
66 R=1024.0f * R_Balance / float( analogRead(AnalogInputNumber) ) - R_Balance;
67 T=1.0f/(1.0f/T0+(1.0f/B)*log(R/R0));
68
69 switch(OutputUnit) {
70 case T_CELSIUS :
71 T-=273.15f;
72 break;
73 case T_FAHRENHEIT :
74 T=9.0f*(T-273.15f)/5.0f+32.0f;
75 break;
76 default:
77 break;
78 };
79
80 return T;
81 }
