LCD Serial Backpack v8 Update

The LCD Serial Backpack (BPK-000), in continuous production since 1994, has been updated to version 8. The firmware is unchanged; the pcb layout has been improved and the circuit tweaked. The updated model is now made in the USA.

Rescuing an Old System with Semicustom Firmware

Success! Modified firmware revives legacy system. 

A customer recently presented us with a common problem: He needed new serial displays for an old system. The catch was that the new displays had to perfectly emulate the old, long-discontinued displays because the legacy system could not be reprogrammed.

He had auditioned several currently available serial displays with varying success. Our GLO-216Y was the best display overall, but its instruction set didn't match the existing setup. Could I help?

Serial Sender Update

Serial Sender v1.4 now supports 19.2 and 38.4kbps.

Serial Sender is Seetron's free Windows utility for sending text and data via a serial port (or USB-to-serial adapter). It requires no installation and no setup. Unlike most full-featured serial utilities, Serial Sender does not monopolize the port; when you press Send, it grabs the port briefly to transmit the data, then relinquishes it. This can be a powerful feature, because it not only minimizes interference with other serial-port users, it also allows you to have multiple instances of the program sending data to the same serial port.

This wrinkle becomes especially handy in light of the coming introduction of GLO-416Y v2.0. Among the new capabilities of the display is on-the-fly baud rate switching, up to 38.4kbps .

Sneak Preview: GLO-416Y Serial OLED v2.0

We're introducing a major upgrade to the GLO-416Y serial OLED. If you've made a suggestion or requested a feature, it's probably implemented in the new rev.

Rev 2.0 devices are available now. Rev 2.0 devices will be available for purchase at the end of September. In the meantime, Check out the upgrade guide for detailed coverage of the new features. A quick list:

• 100% backward compatibility with v1.0. 
• Low-medium-high brightness control. 
• Screen-flip capability (for upside-down mounting, etc.).
• Baud rates from 9600bps to 38.4 kbps
• Larger startup-screen storage, up to 120 bytes.
• Temporary write-protect by serial instruction.
• Alternative carriage-return behavior for separate CR/LF applications.
• Reset instruction to purge the effects of garbage inputs w/out power-down.

As always, if you have any questions or comments, direct them to tech @ seetron.com. 

Arduino Library for GLO-216 and GLO-416

An Arduino library for the GLO- series displays has just been released. The library contains a collection of macros that automatically write Arduino code for the most common display-formatting tasks, such as:

• Cursor positioning: gloSetCursor( col,row )
• Setting font size: gloFont_1w1h thru gloFont_4w4h
• Custom character definition: gloCreateChar( ccnum, patarray )
• Custom character display: gloCustomChar( ccnum )
• Right-alignment: gloSetCursorAlignRight( col, row, width )
• Startup Screen creation: gloSaveStartScreen 
• ...the entire GLO instruction set

The library includes 10 example programs; five each for UART and SoftwareSerial interfacing (with a fix for the soft-serial startup bug). The UART examples have been tested on a MEGA 2560 and 32-bit DUE; the SoftwareSerial examples on  a MEGA 2560 and UNO.

Simple Fix for Arduino SoftwareSerial "setTX" Bug

There's a minor but annoying bug in Arduino's SoftwareSerial library that can trash the first few bytes sent after setup when "inverse" mode is used. It's been a known issue for some time, but is still unfixed in the current version of the library.

The problem is in the "setTX" method in the file "SoftwareSerial.cpp" located in the SoftwareSerial subdirectory of the Libraries folder. This code should set the tx pin output/HIGH for UART-polarity serial, and output/LOW for inverted serial. Unfortunately, it ignores the "inverse" case entirely:

void SoftwareSerial::setTX(uint8_t tx)
{
  pinMode(tx, OUTPUT);
  digitalWrite(tx, HIGH);

RS-485/422 with Serial Displays

A customer recently posed the question, 'Is there an adapter that would allow me to talk to my GLO-416Y using RS-485?' The answer is, happily, you don't need any kind of adapter! 

Assuming that the project does not require multidrop or long wiring runs, you can connect our displays directly to a differential serial port like RS-485 or RS-422. All you need to do is connect one of the RS-4xx data lines to the display' SER(ial In), and tie the GND lines together. That's it.

Almost it: You have to pick the right data line. For most of our displays, you want the inverted line (TxD-); but on some newer displays such as the GLO, SGX, or BPP-440L that have a serial-polarity jumper (Spol), you will need to pick based on the jumper setting.

• Spol installed/intact: Use TxD-
• Spol removed/cut: Use TxD+

For more info on RS-485, the wikipedia entry is pretty good. (illustration above is from their page, courtesy of author Roy Vegard Ovesen).