Serial LCD Display

Keith Hilton

Working out of Parallax book Smart Sensors book Version 1.0 Trying to hook up an old serial LCD display from 2004 that used to work great. On page 5 of the Parallax Smart Sensors book Version 1.0 --- it shows a picture of the LCD display's power hooked to Vdd and GND. RX hooked to pin P14. Then in the back of this same book page 306, 307--- RX is hooked to pin P0, and both LCD displays are shown hooked to Vdd and GND. The most troubling thing is on page 307, quoting from the book: "Since the current draw in either case exceeds the capabilities of all of the BASIC Stamp modules, you should power the Serial LCD from an external 5 V power supply". If that is the case, then why are the pictures showing Vdd, and there is a Vdd place to plug in on most of the Basic Stamp boards? I think I bought my LCD display in 2004. The connection pins on my LCD display are different than the pins on page 5, 306, and 307. My LCD has 5 pins, labeled---+5,GND,SER,GND,+5 My 3 wire connection worked in the past. Running the Baud Rate switch test--both off--does not bring up anything. I have tried running the simple code on page 11, and a error statement comes up no matter how the Baud Rate switches are set. Yes, I have turned the contrast adjustment potentiometer. I have tried running it with a separate 5 volt supply, thinking it needed the 80mA--and yes my power supply will put out a lot more than 80mA. Remembering back how I had it hooked up in the past, I don't think the RX was hooked to either the pin P0 or pin P14. There has been some crazy triangles, squares, and other symbols come up, when powering up trying different things to get it to work. I don't think anything is wrong with it, I think I am not hooking "something" up correctly. Does anyone have any ideas? Thanks!

Genetix

Keith,

You have a Scott Edwards Electronics (seetron) Serial LCD which is different than the Parallax Serial LCD used in Smart Sensors.

Most likely you have this one.
https://www.seetron.com/bpi216/

Keith Hilton

Genetix, you have jogged my memory. Yes, the name Scott Edwards rings a bell from 2004. I had it working with my Basic Stamp back then. Yes, it looks like the unit I have. I will go on the site you listed and see what develops. Then I will be back.

Keith Hilton

Genetix, I got it working. Hello World! popped up. It is amazing what I have forgot since 2004. I am trying my best to get back up to speed with the Parallax Basic Stamp. The Scott Edwards Serial LCD is totally different than the ones Parallax has in their book Smart Sensors. I guess I will have to order the Parallax version to follow the book. Might be able to translate what is in the book to the Scot Edwards Serial LCD. Thanks Genetix for helping me.

tomcrawford

Actually, 216 is not so different from the current Parallax LCD's. Instead of using specific characters to set the cursor position and do control things like clear the screen it uses escape sequences, 254 ($FE) followed by one or more values to set the cursor position, etc. Should be a piece of cake (and a VERY GOOD EXERCISE) to translate.

Genetix

Keith,

Too bad you weren't around a few years back when Radio Shack was practically giving them away.

Parallax doesn't have them on sale at the moment, but I found this.
http://www.rpelectronics.com/27977-serial-lcd-backlit-2x16.html

Keith Hilton

tomcrawford you are correct. Few code differences and other differences.

Buck Rogers

Genetix wrote: »

Keith,

Too bad you weren't around a few years back when Radio Shack was practically giving them away.

Parallax doesn't have them on sale at the moment, but I found this.
http://www.rpelectronics.com/27977-serial-lcd-backlit-2x16.html

**Sees an erco robot waiting for a bus.**

Actually they still are. It is not uncommon for a few to be still on the shelves in certain localities. I bought the first one from a now gone store on the Upper East Side of Manhattan, the sales clerk commented that almost no one bought that stuff. The second one was bought from a store here in Queens, one of a few who do not suffer from the Cell invasion.

Chris Savage

Keith Hilton wrote: »

The most troubling thing is on page 307, quoting from the book: "Since the current draw in either case exceeds the capabilities of all of the BASIC Stamp modules, you should power the Serial LCD from an external 5 V power supply". If that is the case, then why are the pictures showing Vdd, and there is a Vdd place to plug in on most of the Basic Stamp boards?

Most BASIC Stamp development boards have their own 5V regulator on them. THe text refers to powering the LCD from the regulator on the BASIC Stamp module itself, which can't provide enough current to a backlit LCD module. Most boards that hold a BASIC Stamp Module are capable of at least 400 mA of current though.

Keith Hilton

Chris, thanks for your help. Yes, my LCD is backlit. I figured it out and powered the LCD with a separate 5 volt power supply that had enough current. I let both power supplies share the same ground Vss and it has worked.