etap2hw 38 mm I2C to LCD Interface BUILDING INSTRUCTIONS October 2013 P. Verbruggen Rev 1.01 15-Oct-13 Page 1
Table of Contents Chapter 1 General Information 1.1 ESD Precautions 1.2 Further Supplies 1.3 Bill of Materials Chapter 2 Building Instructions 2.1 Points to Note 2.2 Layout of the board Schematics BOM Page 2
Introduction The automation of is based on the Arduino UNO as a basic computer and the following circuit boards: Arduino UNO Universal I/O board Adafruit LCD shield or a 38 mm I2c to LCD board Power Supply decoupling board Tactile switches and Rotary encoder This build instruction is only addressing the 38mm I2C to LCD board Page 3
Chapter 1 General Information 1.1 ESD Precautions The following rules should be applied while handling the board: Avoid carpets in cool, dry areas. Leave PC cards and memory modules in their anti-static packaging until ready to be installed. Dissipate static electricity before handling any system components (PC cards, memory modules) by touching a grounded metal object, such as the system unit unpainted metal chassis. If possible, use antistatic devices, such as wrist straps and floor mats. Always hold a PC card or memory module by its edges. Avoid touching the contacts and components on the memory module. Take care when connecting or disconnecting cables. A damaged cable can cause a short in the electrical circuit. Prevent damage to the connectors by aligning connector pins before you connect the cable. Misaligned connector pins can cause damage to system components at power-on. When disconnecting a cable, always pull on the cable connector or strain-relief loop, not on the cable itself. 1.2 Further Supplies In addition to the parts you ve received you need to use some additional parts like Tools and solder equipment including solder. You also need: As wires are also used with a pin/socket connection it is also recommended to use heat shrink tubing to insulate. A small screwdriver to adjust LCD during first power on 5-32 screws of sufficient length including nuts Washers non-conductive Page 4
1.3 Bill of Materials Check the contents of kit before you start. Resistors: There are 10 resistors in the kit. Capacitors: There is one capacitor in the kit that act as a decouple device in the power line to avoid glitches. Potentiometer: One small trimmer is available in the kit to control the LCD. This trimmer is to be installed on the backside of the board to allow access when the board is installed in your enclosure. I2C Port Expander IC This long IC is your interface using the I2C protocol designed by Philips to allow two-wire communication between devices. Header pins: There are two strips of 36 male pins available to connect the LCD display to the I2C interface board. Tactile Buttons: There are two sets of tactile buttons in the kit; a small and an extended shaft version. Using those is pending your requirements and, as in the Adafruit solution on the automation mostly used to wire to an extra button configuration. I2C Interface board: The 125x38mm board Page 5
Chapter 2 Building Instructions 2.1 Points to Note -Read chapter 1 carefully before starting the project build -This instruction manual is written in a way that it provides you with all the information required to successfully build the unit. It is therefore highly recommended to follow the instructions provided step by step - The placement of the components is structured from low profile parts to higher profile parts, the first parts installed are therefore the resistors then the IC sockets and gradually to the higher profile parts like capacitors. By using this method the board can be put upside down assuring components are all flush with the board when soldering takes place. - It is also recommended to use an AVO meter to measure each resistor before inserting as this guarantees the correct values. (Colour bands are difficult to read) - Points requiring special attention are marked in the build instructions with:!.! Extra attention, part could be placed wrongly * NB Vdd * A part possible affected by alternative build requirements (Chapter 4) NB Remarks on parts not part of the kit This is a connection. - Use solder iron with sharp point at correct temperature and use solder for electronics -Never apply more solder then required. With too much solder applied, bridging between two solder joints can happen creating shorts. Also, note that soldering time of a solder pad that s not connected to the earth shield is less than a solder pad connected to the earth shield because of thermal conduction. Page 6
2.2 Layout of the board Front view of the I2c to LCD board This board is derived from the Adafruit LCD shield with extra features. For the automation project those extra features are (not yet) required but anticipated as being required in a later stage. The 3 resistors R3, R4 and R5 are already installed to make addressing the I2C address of this unit when more I2C devices are added an easy task. Also added are two (2) interrupt outputs also not required (yet). An automatic control of the backplane light is also foreseen but not installed. Page 7
Step1: Place Resistor R1 4K7 Ohm (yellow violet red). It is recommended to keep the tolerance colour to the right or left as you would possible also do with the other resistors to make it a tidy assembly. Step 2: Place Resistor R2 4K7 Ohm (yellow violet red) Page 8
Step 3: Place the (red red brown) resistor into the location marked RED Step 4: Place the (red red brown) resistor into the location marked BLUE Step 5: Place the (orange orange brown) resistor into the location marked GREEN Page 9
Step 5: Place 3 10K Ohm (brown black orange) resistors in resp. R3, R4 and R5. Step 6: Place 1 10K (brown black orange) resistor in location R6 Step 7: Place 1 39 Ohm (orange white black) resistor in location R9 Page 10
Step 8: Insert jumper JP1 between 2 and 3 Step 9: Flip the board so the back is visible and insert the trimmer potentiometer in the location shown. Step 10: Insert the capacitor into the other location. Page 11
Step 11: Insert 18 pin header with longest pins pointing upwards. The 18-pin header is required for the RGB display a mandatory display as colour changes are cue s to the operation status. Just soldering one pin to check alignment then the opposite pin and, again, check alignment. With a double check of exact 90 degrees angle you can solder all 18 pins. Step 12: Insert the I2C IC. Please note the indentation mark to be aligned with the silkscreen image. If required bend all pins to ensure alignment before insertion. When inserted solder one pin and recheck seating of IC then the pin parallel on the other corner and check again for perfect seating of the IC then solder all pins.! Page 12
Step 13: Apply bushing with minimum height of 5mm and maximum height of 7 mm. A method is to use long screws from the back as a temporarily mount/alignment aid. The holes of this assembly and the LCD display are for 5-32 screws, a M2.5 would also be a good idea to use when available. Before soldering the display check if sufficient clearance is between the LCD display and the I2C to LCD components. A clearance (air gap) of >1 mm is acceptable. When correct soldering can take place by soldering first corner pin, check alignment and readjust if required, solder opposite pin, check alignment again before soldering all pins. Page 13
Step 14: Connect wires to unit Connecting the I2c to LCD assembly to the Universal I/O board is by means of a 4 position connector. The colour BROWN goes to the 5Volt, RED to the GND, ORANGE to SDA and the YELLOW to SLC. There are two connection not connected. Step 15: Some Thoughts Some thoughts of installing this to the enclosure is pending your disclosure and the means you have to mount it. A possible advise is to use a countersunk screw with sufficient length (32-5 or M2.5) inserted from the outside of the enclosure. Then use nuts to control spacing between the LCD display and the enclosure. When the screws are of sufficient length nuts can be used to finally install the unit to the enclosure. When nuts are applied for mounting the assembly to the enclosure the use of non conductive washers is a must to avoid shorting of the unit to ground. In the area of the tactile switches used on this assembly, some additional holes are available in the event that this area needs additional strength. The tactile switches, part of the kit could be used not fully inserted or fully inserted making this a height variation flexibility to the actual spacing you ve chosen for the final solution. Page 14
Qty Value Device Parts 5 10-XX DOWN, LEFT, RIGHT, SELECT, UP 1 JP2E JP1 1 0.1uF C5/2.5 C2 2 4.7K R-US_0207/10 R1, R2 4 10K R-US_0207/10 R3, R4, R5, R6 1 10K TRIM CONTRAST 1 39 R-US_0207/10 R9 2 220 R-US_0207/10 BLUE, RED 1 330 R-US_0207/10 GREEN 1 HD44780LCD_RGBLONGPINS HD44780LCD_RGBLONGPINS U$1 6 LSP13 LSP13 5V, GND, INTA, INTB, SDA, SLC 1 MCP23017SP2 MCP23017SP2 IC1 Page 15
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