SparkFun Forums

[boubele]

Hi all,

I would like to build a USB connected LCD for use with LCDproc (and possibly LCDSmarties). I was thinking about using the Breakout Board for FT232RL USB to Serial but the 3.3 won't power a serLCD as far as I can tell. Any suggestions, guidelines ?

Erik

[billroy]

I am driving a SerLCD off the +5 and it works fine. And you have USB tx and rx right there on pads.

[boubele]

Oh, so you're using that breakout board ?

The web site says "VCCIO is now tied to 3.3V through a solder jumper. You have the option of clearing this jumper and tying the VCCIO pin to 5V or any other IO voltage you need.".

I don't think this board does 5V anymore, only 3. Seems you can supply 5V externally but I'd like to avoid that.


What software are you using with it ?

[emf]

That means there are two small surface-mount pads on the breakout board that have a blob of solder shorting the two together. In this configuration, VCCIO is set to 3.3V. You can remove this blob of solder and then connect VCCIO to 5V using the pins on the .1" headers. The Vcc pin should give you 5V that you can use to power the LCD.

[boubele]

So you guys were right, removing the jumpter did give me 5V on VCCIO which powers my LCD without any issues.

I think I was a little naive as to how easy the next step would be. I connected my SerLCD RX to the breakout board TX. I then tried to connect a few terminals applications (9600,8,0,0) and transmit characters (by typing them) but no go.

I have verified that my serLCD is working well using an Arduino and communicating with it using the Arduino Sparkfun serLCD library.

I tried on Windows, with PuTTy and LCDSmarties (with the sparkfun driver) and on Mac OS X with a basic screen and the Arduino Serial Monitor.

What am I missing ?

[emf]

So you guys were right, removing the jumper did give me 5V on VCCIO which powers my LCD without any issues.

I can't tell if you did this part right or not. Just clearing the jumper should leave VCCIO floating. After you clear VCCIO, you need to connect VCCIO to the VCC pin to set it to 5V.

Once you think you have it hooked up correctly, the first test should be a simple loopback test -- connect the RX and TX pins together and then see if it echoes everything you type.

[boubele]

So it's kind of hard to figure out on this breakout board what is what.

With the board in front of me (USB towards me, 3V/TX/RX/GND away from me)

On the right side at the top, I have VCCIO and VCC at the bottom.
On the left side, I have CTS on top and TXD at the bottom. I believe that's correct.

If I understand you correctly and I think I get it now, by clearing the jumper I have de-associated 3V with VCCIO but I have nothing connected to VCCIO so I need to bridge VCC and VCCIO with a cable. That's probably why it's not working, right, there is no juice going to the FTDI chip and nothing coming out of TX as a result. Am I correct ?

[boubele]

Got it working. Will post more tomorrow so as to guide people who made the same mistakes I did.

[boubele]

Making tons of progress but for some reason LCDSmarties set the SerLCD communications down to 4800. I know I had to send <control>m to re-set it to 9600 bauds but I couldn't figure out what the ascii code would be.

I eventually did:

void setTo9600bds(){
mySerial.print(0xFE, BYTE); //command flag
mySerial.print(0x0D, BYTE); //set speed to 9600 bauds.
delay(150);
}

or in terminal at the appropriate speed you can type '|' (pipe) followed by the Return key (Ctrl M) to reset to 9600

[rfryar]

Here is the driver I created for the Serial Enabled LCD panel that spark fun sells for the LCD Smartie program. It should save you some work.



http://lcdsmartie.fryar.org/serlcd.php

Enjoy!

Rick