Today I will show you how to make an LCD shield for Mediatek's LinkIt ONE board. The process is not too hard and the cost is very little when compared to LCD shields you can buy at vendors like SparkFun electronics, Farnell and so on.
Now let's get started!
Step 1: Materials and Tools
You will need what you can see on the photo:
- HD44780 compatible LCD
- bredboard (at least 14x20 pins)
- some pin
- some soft insulated wire
Aside from that you will also need soldering iron with solder and pliers.
Step 2: Pins
Cut pins so they fit in slot D0-D7 and 5v,GND. pins can extend to as many slots as you want as long as they cover those pins and still fit in your bredboard.
Now put pins in correct slots and cover that with bredboard. Here comes soldering. Solder only first and last pin if each row, then detach shield from LinkIt ONE to avoid damaging it. Solder remaining pins and reconnect the shield.
Now just place LCD pins on bredboard and place LCD over so you see how it fits. If possible, make sure there is at least one row of holes between any two rows of pins. When you are satisfied with positioning, detach shield from LinkIt ONE and flip it upside down (still assembled). Once again solder first and last LCD pin to bredboard, remove LCD and solder the rest.
Now the base is ready and you can move on to next step.
Step 3: Making Connections
This is the fun part. you must connect correct LinkIt ONE pins to correct LCD pins.
I did that using insulated wire which had insulation easily melted away with soldering iron (all wires that aren't wrapped in thick plastic shell are such).
Because some pins have solder space on one side and others on toher side of bredboard, you will have to run wire through holes (remember how I told you to leave at least one row of holes between pins?).
If you will be using pins 2-7 for controlling LCD, follow this connection list:
- +5 - PWR
- gnd-0 //contrast, you can connect it to potentiometer
If your LCD has backlight, connect it to +5 and GND (though you may need to add a resistor between source and LCD).
I really wanted to make some good pictures of how wiring process looks like but with wire this thin... Impossible. If you take a look at third picture above, you might see some thin lines between bottom two rows and that is the best picture I managed to take... Sorry about that.
But I trust you can do it!
Step 4: The LCD
Before soldering on the LCD, check if there are no short circuits and if all pins are actually connected (you should be doing that after soldering each connection and not at the end - it might save you lots of trouble.
Also check if everything works before you solder it together as there is no turning back after you solder first two pins. This can be done either by placing LCD on pins and gently twisting it so all pins make contact or by using wires.
When you confirm it all works, you can solder it together. If something is off, check your connections and fix what is wrong.
Hope you liked this 'ible and enjoy using your ultra cheap LinkIt ONE LCD shield!
And in case something goes wrong:
P: screen is blank
S: is power on? is contrast pin on LCD connected to GND?
P: I hear a buzzing nose, LinkIt ONE LEDs are blinking
S: you have a short circuit. Try to find and fix it