The basis of 1-Wire technology is a serial protocol using a single data line plus ground reference for communication. A 1-Wire master initiates and controls the communication with one or more 1-Wire slave devices on the 1-Wire bus. Each 1-Wire slave device has a unique, unalterable, factory-programmed, 64-bit ID (identification number), which serves as device address on the 1-Wire bus. The 8-bit family code, a subset of the 64-bit ID, identifies the device type and functionality. Typically, 1-Wire slave devices operate over the voltage range of 2.8V (min) to 5.25V (max). Most 1-Wire devices have no pin for power supply; they take their energy from the 1-Wire bus (parasitic supply).
More about 1-Wire technology may be found on Maxim IC web pages.
1-Wire master communication interface
This instructable will show how to implement and use basic serial 1-Wire master communication interface like one show on picture (link).
Step 1: PCB for Project
This very modular PCB have two parts :
- 1-wire serial communication interface
- voltage regulator parts (using 78xx IC)
Pictures show both side of PCB.
PCB give possibility to use SMD or normal scale elements for accomplish functionality on most parts, and different connection options.
In some small number cases you may use 1-Wire device without any additional power supply. How ever when you try to do just little complicate things with more 1-Wire devices or with longer communication lines (wires) you will need to supply 1-Wire device with proper power.
Step 2: Parts for Project
Besides PCB we have 3 groups of elements :
Voltage regulator (5V)
- 7805 IC (T1)
- elco 100 uF (Cin)
- elco 10 uF (Cout)
- 2 pin screw terminal 200mil (P1)
- 2 x 2 pin 100 mil with cap connector (J1 & J2)
- Schottky 1N5407 (sD5)
- LED smd blue (LED)
- resistor 100 (R3)
1-Wire serial communication interface
- 2 x Schottky diodes (1N5818) (sD2 & sD1)
- 6.2V Zener diode (zD4)
- 3.9V Zener diode (zD3)
- resistor 1.5 k (R2)
- 1m flat 10 wire cable
- 2x5 pins header (RS232H)
- IDC 10 pin connector
- IDC 9 pin female D-sub connector
- 5 pin screw terminal 3.5 mm (1-Wire Bus)
Schematic for both part of project are in pictures.
Step 3: Step 1. Soldering Small SMD Parts (bottom Side of PCB)
R = (5 - LEDreV)/LEDI
LED orientation is defined with mark on board, and mark on bottom side of LED like is shown on picture.
Step 4: Step 2. Soldering Lower Top Parts
Picture show how to bend connection wire of elements to nicely fit on PCB. Also all mark on diodes fit to marks on PCB (shown on picture) for easy orientation.
Step 5: Step 3. Soldering Other Top Side Parts
Next solder 5 pin screw terminal 3.5 mm (1-Wire Bus) and 2 pin screw terminal 200mil (P1).
Finally in my configuration I need to solder two shortcut wire. First at position SW which is dedicate for power switch (if you use some solder switch wire in that place) and second one on position P2 (like was shown on picture). This shortcut is needed because of power supply input terminal organization (more on picture) .
Step 6: Step 4. Soldering Other Bottom Side Parts
Step 7: Step 5. Soldering Voltage Regulator
Printed mark on PCB suggest orientation if you use other type of voltage regulator (In, GND, Out) .
Step 8: RS232 Connection Cable Using IDC Type Connector
ADDitional INFO: in some series of PCB 10 pin connector doesnt have proper order of wires for 9 pin D-sub connector (direct one2one order) and follow reorganization of wires is needed 1,6,2,7,3,8,4,9,5 . When you got PCB that is clearly marked
Step 9: Final Step: Power on and Use
Connecting 1-Wire device may be done using 1-Wire Bus terminal wire connector (Green one). Connection lids are follow :
1- + Unregulated voltage
2- +5V regulated voltage
4- 1-Wire DATA
5- NC line
RS232 IDC D-Sub connector need to be connected to PC. You may use any of 1-Wire connection software like digitemp or Java API and java library.
Also for more info you may read nice instructable, with similar content.