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LCD and Touch booster pack

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After getting in contact with Larsie I managed to buy one of these modules. I went for the non-touch version since it has a space to mount an MSP chip on a DIP socket, bind that to an Anaren AIR module and you have a neat small package. Better than my current setup where I am using a 16x2 LCD to display the info that goes around in my wireless test-system.


The board arrived swift - not so odd as Norway isnt that far away from the Netherlands - and I got it up and running rather fast. It was easy to use the LCD and the Anaren AIR module together, no needs to configure anything special. Rewriting the old LCD-code to the new SPI-driven setup was easy. Larsie also helped me out connecting the backlight.


Here's how the module looks after installing and creating some code to see the output of the wireless nodes. I even managed to get a graph of one of the nodes that displays the change of its readout. And yep ... no buttons installed yet.



One thing however isnt optimal yet, when the LCD is positioned normally (so you can read it easy) the Anaren AIR module is positioned sideways and the antenna isnt oriented optimally. Next step I am currently working on is using a rotated font and the first steps into that seem to be going in the right direction.




Its a nice small display that can be helpfull during development allowing you to have both text and graphics (albeit limited !) on a screen. I am happy Larsie made this and that I am able to use this.




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Code is at github.com/mobilars/LarsLCD let me know how it works.


It is for IAR, but CorB has adapted to CCS. There are several main-files with different apps. He has also contributed some good font functions back into the iar code.


I have used 2553, but it should fall back to a bitbanging driver for non usci chips.

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The display is in the store now, in 7 pieces of each. I have 200 displays being delivered next week, so will make more during the summer :-)

Button: http://store.43oh.com/index.php?route=p ... duct_id=78

Touch: http://store.43oh.com/index.php?route=p ... duct_id=79


I've attached some CCS example code.


(B# edit: Added links. Images need to be changed to hi res)


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Wow, that's a really good price.


The boards that are in the store now have room for a SOT-89 regulator, but the middle pin is Vin (MCP1702T-3302E/MB IC, LDO REG, 250MA, 3.3V, SOT-89).


For v2, I changed to a NX1117CE33Z LDO, 3.3V, 1.25%, SOT223. That's a bit confusing I guess, but I made a typing mistake when ordering a few of these other regulators, and suddenly got 150 of them :D so I thought it was better to start using SOT223 instead. V2 doesn't have other major differences.

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Yes. The v2 and v3 boards (now in store) have space for a mosfet to turn on/off backlight via IO, but I haven't tested it yet so these aren't soldered on by default. Planning to test it this weekend and can get back with info. I'll also test how much the backlight actually draws.


Edit1: The mosfet works, and you can control the backlight from Port 2.5. The mosfet is a 2N7002PW, SOT323. I'm using this one.


Edit2: It is probably possible to drive the backlight directly from the IO if you have a large enough resistor in-between. I didn't realize this until now. The backlight draws 4 mA at 3.6V if you use a 150ohm resistor in series with the backlight. If you run the backlight at this voltage without a resistor it draws about 30mA, which is too much and will probably trigger the current-limiting feature on the IO port. If you increase the resistor to above 200 ohms, which still gives an ok light, you should comfortably be able to use the IO directly without a transistor. You can always measure it to make sure before you connect it to the IO port.


If you let me know which board you're using I can let you know exactly how to wire it, but you can also look the schematics on http://lars.roland.bz/lcd/ (click the sub-page for the version and type of display you have).


Basically, (IO-port) --- (resistor) --- (backlight-connector)


It is the ground-side of the backlight that is available, so you need to drive the IO-port low to light up the display.

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Thanks Larsie.


I have the LCD Touch V2 (with the correct label for pin 2.0). I can have a look in the morning to work out where to pick up the backlight connector, although I wont complain if you have a quick answer :)

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Haven't tested the following configuration yet, but I think it'd be something like that on this picture. The two button-pins closest to the LCD are connected to the negative side of the backlight. The positive side is already connected to VCC (3.x volts). I'd use a resistor with value equal or above 200 ohm, 220 ohm should be fine. The pin on the board is P1.0, which is the same as the LED on the Launchpad. I'd maybe disconnect the LED jumper on the launchpad. Those who have the Button-board need to use a different IO-pin, as the P1.0 is connected to one of the buttons.


A 200 ohm resistor would give a current of 2-5 mA depending on VCC which should be fine for the IO-pin, but if you're drawing a lot of current from the other pins, the port-limiter may lower the voltage. You can check this by checking the voltage on the pin when you have the backlight on. 2-5 mA won't be very bright of course, but should be fine for most purposes. If you're using 3V voltage, you may want a smaller resistor.


Have tested using the IO (P2.0) on the button-board, and this works well.



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Some power measurements on the lcd-button-boosterpack. Using 150 ohm resistor for backlight, an IO pin to drive the backlight, and the MSP430 soldered onto the boosterpack (so without Launchpad). The current measurements include the MSP430 and LCD. The MSP430 is in low-power-mode 4. (EDIT: this post earlier used LPM0, but I have changed it to LPM4, where the MSP430 uses 0.1mA less).


VCC = 3V

With backlight: 1.7 mA

No backlight, some text on LCD: 0.19 mA (0.21 mA if almost all the display is black)

No backlights, lcd turned off (PD=0): 0.01 mA


VCC = 3.5V

No backlight, some text on LCD: 0.25 mA


VCC = 2.2V (backlight does not work at this voltage)

No backlight, some text on LCD: 0.11 mA

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