I’m new to this and found the datasheet unclear and inconsistent about how to clear screen etc.
Serial.print(0x7C, BYTE);
Serial.print(0x01, BYTE);
Just wasn’t doing it!
Several hours of searching finally answered the question! to clear the screen you use this;
Serial.print(0xFE, BYTE);
Serial.print(0x01, BYTE);
A really useful explanation and more info is to be found here;
http://www.arduino.cc/playground/Learning/SparkFunSerLCD
No author mentioned, but thanks whoever you are! :–)

I am using a PICAXE 20m chip and I don’t know what the serout command should be can someone please help me here.

Will this work with the 16x2 3.3V LCD? I am afraid that it will only work on 5V ones

The source files provided do not match the current hardware. You can easily see this from the hardware port definitions.
For example, the source says:

define BL_Control PORTA.4

But backlight is clearly controlled by pin#1 (PORTA.2).
Can you provide the updated source code? I bought a couple and wish to change their operation.

Hello!
My Serial Backpack arrived when the firm more or less insisted it would.
I have just completed a trial using it with the LCD display program for Linux LCDd and lcdproc, and after configuring the program to think it was talking to a certain vendor it just worked perfectly.
Additional details, the display is one that was a “pull” I believe it was recovered from the display for an older laser printer. And the programs were retrieved from www.linuxpackages.net and the serial device talking to both is a USB breakout board for the FT232R device.
In a word, “Finestkind!”.

Just a suggestion for the next revision of this excellent product. How about adding in a keypad encoder function? The encoder would scan up to a 4x4 keypad and output the key press information on the TX line of the serial port. (Similar to this, http://www.robot-electronics.co.uk/htm/Lcd03tech.htm)

In the data sheet the “CHAR” labels could be more clearly explained. I eventually figure out that they are a type of ASCII command and found a table that list the hex equivalents for each “CHAR” command you have listed. A suggestion for future revision of this document would be to include the hex version of each command statement instead of only listing the keyboard command, since they are not always available when controlling the lcd from a microcontroller

When i recived this i had some problems making it work.
Text sent to display showed up as garbage.
Startup message displayed nicely.
After issuing a 0x12 (ctrl-R) while startup message showed, resetting the chip to 9600 baud it worked perfect.
Very nice product.

When looking at the backpack with the pins facing away from you, which is pin number 1? there are no markings on my backpack?
Also, How can i get it to communicate with a BS2?

I agree with the need for a little clarification in the docs… my (also recycled) Sharp LCD has a 2x7 (data) + 1x3 (backlight LED) header for the interface, so does not plug straight in… where is pin 1 on the backpack? There is a suspicious dot at the far end away from the serial/power screw terminals, but it IS NOT PIN 1!!!! There is a cryptic reference in the datasheet to pin 15/16 as being near the sparkfun URL, [which is not on the current board…] (but is in the image in the datasheet). Once I got that sorted, it works great! I would suggest a diagram included with the pinout doc that shows the pin orientations.
Also on commands, it is still not clear to me what to send to program the LCD size, after the command byte (0x7C) do you send “3” [0x33] or 0x03? And how do you use the cursor (blink/underline) on/off? [which should also include the 0x09 command for blinking text?] I have the positioning commands working.

Backlight off doesn’t seem to work (at least with the source code zip provided).
backlight_counter is being incremented and then checked if its equal to brightness_setting, which will never occur if brightness is 0. So off is the same as 100%.
Although I suspect the intention was to disable the timer interrupt if brightness_setting = 0?

Anyone got advice on controlling multiple HD44780 LCDs with a single backpack? New to micros, can I just independently wire up the enable and add all the LCDS to a single “bus”?

Could somebody please clarify the waveform needed to communicate with this device?
1 Start Bit, 8 Data Bits and 1 Stop Bit. Doesn’t tell me enough.
Is this active-high or active low? What should be the polarity of the Start and Stop bit, and what should the RX pin be forced to in the idle state, or when we are not transmitting data??
I’m trying to get this to work via an FPGA and I’m having weird results.
Thanks!

Great product. Saved me lots of headaches with a 20x4 LCD, HD44780-compatible.
I tested it on my PC using the 5V FTDI serial breakout “DEV-09115” also bought here.
The command for enabling/disabling splash screen (0x7c-0x09) is not yet documented in the PDF datasheet. The setting is saved in the EEPROM for next reboots.
I had to reboot (power cycle) the LCD display after every command changing the LCD setup (0x7c-0x03 to 0x7c-0x06); anyway, these are stored in the backpack EEPROM as well, thus once set I don’t need to use them anymore.
My software just issues a 0xfe-0x01 sequence (clear display) and 80 characters (blank-filled). The 9600 default speed is more than enough for that (less than 0.09 seconds for sending a full screen update).
I was also able to define graphical characters sending the command 0xfe-0x40 and then from 1 to 8 sequences of 8 bytes containing the bitmaps (for example 0x15-0x0a-0x15-0x0a-0x15-0x0a-0x15-0x0a will define a 5x8 checkered pattern) and finally a 0xfe-0x01 (clear screen ending bitmap definition mode). The defined characters are 0x00 up to 0x07. Characters are stored in CG-RAM of the display; this means that they will have to be redefined on every reboot.

Nice gadget!
Just got 15 pieces to Finland, and made them to work with a PICAXE processor. If someone is interested what settings should be used, it is here: http://www.picaxeforum.co.uk/showthread.php?p=134442#post134442
As I said ,a very nice product, but the manual really needs a little shaping…
Most things are already discussed here, and could be “transferred” to the manual.
AND a little warning! I noticed that in many lcd’s ,pins 15 and 16 can be next to pin1 !
So, check carefully Your lcd’s datasheet, else You could stick the backpack to all wrong holes…

I’ve bought one of these.
I don’t seem to be able to make it work!
no matter what I do I can’t print anything on the LCD! And I keep getting the splash screen!
The specifications says the splash screen comes on after 500ms, it doesn’t! It comes after probably 10 seconds! Then when it’s on the backlight keeps flashing on and off!
Any help?

“SFE, could you please post the schematic and source code for v2.5? The versions you have now appear to be the v2 (with the 16f688). Thanks!"
Also,
Picture of backpack shows a 20 pin device and crystal.
The 16f688 is a 14 pin and should not have a crystal according to the manual.
Manual picture appears to be right.
Thanks

I found this on your forum back in March.
I am hoping to roll my own.
Any help would be appreciated.
Thank you
“Bonz099
Post subject: SerLCD 2.5 Hex?
Posted: Sun Mar 07, 2010 3:33 pm
Replies: 0
Views: 54
Im having trouble locating the hex file for the v2.5 serial backpack all I see on the site is the 2.0 version. When I write it to my backpack via the ICSP header it just gives me 2 black lines (row 0 and 3). Also if someone had the source+updated schematic for it as well, that would be VERY helpful,…”

Thank you, Robert.
“ by RobertC. is a SparkFun employee
RobertC.
| Sep 28, 2010 at 1:02pm
Yep. I’m working on revising this whole page with new and updated information. In the meantime, you can email techsupport@sparkfun.com and get what you need.”

Hello,
What is the part number of transistor on this board?
Thank you.

Ok i’m having trouble changing the baud rate and saving the splashscreen.

The manual says “j” to save the splash screen, however theres no way i can get that to work.

What is “j”?

i tried sending J i tried sending j tried even sending “controlj” and “j” and another half dozen variations.

How the heck do i perform a “j”

is there a way to hook this directly up to a usb cable to program it?
If so how does one do so?
Thanks

Could someone please explain where pin 1 is? I’m asuming it is the pin above the dot & “spark” logo that are both on the side with the PIC…
—Thanks—

I am trying to change the baud rate on my SERLCD_v2 but am getting no joy. The datasheet says to send (124, control m) but I have tried all possible combinations and it keeps receiving at 19200. Could anyone please tell me what the code should exactly look like.
I am using a picaxe 20X2.
Thanks

…

On a black on green 20x4 lcd, the backlight flickers quite a bit. Any suggestions on how to eliminate it? It’s being powered from an Arduino UNO’s 5V line via a breadboard.

Before applying power, I was studying the backpack to make sure I understood which pin was which and ended up having to unsolder the screw terminal connector block to repair an open trace under the connector. There was no continuity from the 5V screw to the nearby 5V header pin, JP1 pin 5.
As a matter of fact, initially there was no continuity from the 5V screw to anywhere at all.
So, there were two problems, an open trace, for sure, to the header pin, and a bad solder connection from the screw terminal pin to its hole, so that the 5V trace that leads to the components was also not connected to the 5V screw. After fixing the open trace and resoldering the connector, the board powered up OK and works fine.
I use HyperTerminal to send the commands and control characters. Use the ALT key and numeric keypad or equivalent keyboard numeric keys.

I’m trying to get the serial LCD backpack to work with an MSP430 launchpad and Powertip pc2004m 4x20 lcd.
My first problem is no splash screen on power up. LCD is lit but blank. Any suggestions are appreciated.

I’m trying to set the Splash Screen on this version 2.5 LCD Back Pack with LCD.
The Back Pack docs says to setup the LCD message and then send 124 and J. What is the decimal or hex representation of Control J?? Here is my code, control J ?????
main: hserout 0,(0xfe,0x01) ;clear lcd

pause 100  
hserout 0,("SPLASH N CUR")  
hserout 0,(254,199,"X",124,"j") ;set cursor pos and make the splash screen.  

??? thanks ,,,, Bill

Tip #1: Want faster refreshing when using the LCD-0255? Use cursor addressing as described in the SerLCD V2.5 Datasheet.
Tip #2: To prevent loss of serial comm between the MPU & SerLCD, include in the INIT portion of your program to set the speed (9600) and clear the LCD display else at times the SerLCD and LCD display will fail to display past the power on ‘Splash Screen’.
Tip #3: program the splash screen with the program name and version being run or tested. Update when the program version changes. These steps help as a reminder as to what your were last working on .

Bought this to go on my 16x2 LCD. The LCD backlight turns on, but I get no splash screen, and it is unresponsive to all commands. Occasionaly the backlight will shut off or blink on and off slowly. I took it and hooked my LCD up parallel again, and it works perfect. Any ideas? Maybe I’m just not grasping the concept of TTL, but any and all code examples I could find produced the same result.

To create and use custom characters go here.

Mine displays garbage characters when the input is floating. I am using it with an Arduino (using softserial so it doesn’t conflict with the USB->serial) that configures all pins as high impedance inputs on reset, which immediately overwrites whatever is on the display. Perhaps the next rev could include a pull-up resistor on board?

I ordered LCD-09067 which is white on black serial LCD. It worked with orignal package.
using MPLAB with PICKit 3, I could load the modified version which was from serLCD-v2.7, however, it did not work for some reasons. After that, I reloaded the orginal firmware from SerLCD-v2.zip or SerLCD-v2.7xx.zip. Neither did it work. I doubt the firmware and source code are not the working version.
Any ideas?

Put this on a 20x4 parallel LCD. The included firmware seems to be for a 16x2 cause I cant access the bottom 2 lines of the 4 line display.
I assume I need to load the 20x4 firmware. Can this be done with an arduino or netduino?

I haven’t been able to successfully change the baud rate and I haven’t been able to find anyone on the internet that have either. Can someone from Sparkfun please respond to this message telling us how to change the baud rate? Thanks

I have ported LiquidCrystal library for use with the serial LCD you can look at my code here. Still working on finishing all the documentation. But putting up for now hopefully someone will find it usefull.
http://arduino.cc/playground/Code/SerLCD
-Thanks

Has anyone been able to control the back light brightness? I have communication with the LCD, but none of the commands seem to adjust the back light brightness. Other than that, this product works well with my 20x4 LCD

Have anyone tried to make this backpack from scratch with these files (PCB and Firmware)
Im trying but im failing again and again. I have PIC16F88(PDIP not SMD) and 10MHZ crystal. But i cant get it working.
Can anyone help ?

Watch out! As shown in the schematic, this board has no current limiting resistor in the backlight drive circuit! Some LCD displays have built-in resistors permitting direct connection to a 5V supply, and their datasheets will say something like “Backlight 5V @ xx mA”. But many (including some sold by SparkFun) do not. In that case, the datasheets may show backlight connections named LED A (anode) and LED K (cathode) and list a maximum forward current and a corresponding LED voltage drop. If you have the second type of LCD and you hook up this board, it will attempt to drive the full supply voltage across the backlight LED. SparkFun needs to add a resistor to the design and a jumper to bypass it when safe to do so.

While you’re at it, you also need to add a pull-up resistor on pin 4 (Vpp). This pin is an input (not input/output) and should not be left floating. Another pull-up on the RX pin would also be advisable. Your custom-built serial-enabled LCDs are also in need of these.