Difference between revisions of "Coinvox 22"
(display update) |
(keypad and display update) |
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* IC2: [http://www.nxp.com/documents/data_sheet/PCF8576.pdf PCF8576T] (Universal LCD driver for low multiplex rates, I<sup>2</sup>C address 38h) | * IC2: [http://www.nxp.com/documents/data_sheet/PCF8576.pdf PCF8576T] (Universal LCD driver for low multiplex rates, I<sup>2</sup>C address 38h) | ||
* IC3: [http://www.nxp.com/documents/data_sheet/PCF8574_PCF8574A.pdf PCF8574T] (Remote 8-bit I/O expander for I<sup>2</sup>C-bus with interrupt) | * IC3: [http://www.nxp.com/documents/data_sheet/PCF8574_PCF8574A.pdf PCF8574T] (Remote 8-bit I/O expander for I<sup>2</sup>C-bus with interrupt) | ||
| − | *: Addresses tied to ground; address 20h | + | *: Addresses tied to ground; address 20h. |
'''J''' | '''J''' | ||
| Line 45: | Line 45: | ||
'''Display''' | '''Display''' | ||
| − | * 8 & | + | * 8 × 14 segment display, charachters are filles from the right |
* 52 pins with the only the outer 9 connected (36) | * 52 pins with the only the outer 9 connected (36) | ||
* uses 4 backplane mode (all corners) | * uses 4 backplane mode (all corners) | ||
| + | |||
| + | Segment layout | ||
| + | <pre> | ||
| + | 15 | ||
| + | _________ | ||
| + | |||
| + | | \11 | / | | ||
| + | 2| \ |7 /6 |14 | ||
| + | | \ | / | | ||
| + | 10---- -----5 | ||
| + | | / | \ | | ||
| + | 1| / | \4 |13 | ||
| + | | /9 |8 \ | | ||
| + | __________ | ||
| + | 0 o12 | ||
| + | pin 3:N/C | ||
| + | </pre> | ||
| Line 83: | Line 100: | ||
|} | |} | ||
| + | To read out the keypad (on interrupt pullup), set one row low and read the column nibble. Repeat for each row. Low bit means key pressed. | ||
Revision as of 17:05, 25 October 2015
| Project: Coinvox 22 | |
|---|---|
| Featured: | |
| State | Active |
| Members | xopr |
| GitHub | No GitHub project defined. Add your project here. |
| Description | Get an old payphone to work again |
| Picture | |
| No project picture! Fill in form Picture or Upload a jpeg here | |
synopsis
I got myself a Coinvox 22, reasonably cheap. The downside is: the inner workings have been stripped out, so it's just a metal box with keypad and display, a handset with hookswitch and a smalltransformer.
No coin mech, no ringer, no phone.
inside
handset / hookswitch
- 2 differend reed switches
- 4 coils
- 2 3-pin SOT 23 (smd) diodes(?) (D1, D2: A7 P 45)
J1
|o spk |o| mic - |o| mic + |o spk
J2
mic+ 2 |oo| 1 spk spk 4 |oo| 3 mic- NC1 6 |oo |5 n/c NO1 8 |oo| 7 P1 P2 10|oo| 9 NO2
Note: SW1 switches first (about 2mm) when hanging up
keypad / display
- IC2: PCF8576T (Universal LCD driver for low multiplex rates, I2C address 38h)
- IC3: PCF8574T (Remote 8-bit I/O expander for I2C-bus with interrupt)
- Addresses tied to ground; address 20h.
J
SCL 2 |oo| 1 SDA
4 |oo| 3
GND 6 |oo |5 VCC
8 |oo| 7
Int 10|oo| 9
Display
- 8 × 14 segment display, charachters are filles from the right
- 52 pins with the only the outer 9 connected (36)
- uses 4 backplane mode (all corners)
Segment layout
15
_________
| \11 | / |
2| \ |7 /6 |14
| \ | / |
10---- -----5
| / | \ |
1| / | \4 |13
| /9 |8 \ |
__________
0 o12
pin 3:N/C
Keypad
| col1 (P7) | col2 (P4) | col3 (P5) | col4 (P6) | |
|---|---|---|---|---|
| row1 (P1) | n/c | 1 | 2 | 3 |
| row2 (P1) | n/c | 4 | 5 | 6 |
| row3 (P2) | N | 7 | 8 | 9 |
| row4 (P3) | Vol | * | 0 | # |
To read out the keypad (on interrupt pullup), set one row low and read the column nibble. Repeat for each row. Low bit means key pressed.
- LGCO-CH BTC15 DESKII
- 4 431 4223 0 22
Sticker
- Landis & GYR
- 412197580 A
- Version.mec: A
Date fab : 02/95
plans
- upload reference material of the Coinvox phones (hacktic, 't klaphek, telephone museums ([1][2][3][4][5][6][7])
- experiment with my (front fed) coin mech (or look for a top fed mech that fits)
- experiment with a cisco phone (see if I can use the softkeys and the AUX port to read quarters or just Euro coins
- connect an ATA to an old phone
todo
- identify ICs, obtain datasheet, determine pinouts
