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Sunday, 25 May 2025

Ode to the Belgian football champion 2025: Union Saint-Gilloise


We are the Champions!!

90 years after the previous title, it has finally happened: USG has secured a well-deserved new championship title after the most spectacular series ever played in the history of the playoffs.

DEAF8 tribute to the new champion!

Sunday, 22 February 2015

Arduino Proto Shield even better!

Last blog post I introduced you to the Arduino Proto Shield, a great solution for Arduino development. Thanks to the extra prototyping areas with soldering pads I was able to even improve the functionality of the board!

This is what I added
  • extra male headers next to all I/O and power pins
  • added serial/I2C/IIC adapter board LCD1602 to be able to control the LCD+backlight with only 2 I/O-pins + LCD pin reassignment via jumpers (control + power + backlight)
  • DS1307 real time clock + 24C32 EEPROM-pcb
  • MCP23017 chip on free soldering pads under LCD display -> 16 extra I/O-ports!
  • buzzer on free soldering pads under LCD display
  • 6 extra Grove compatible IIC-connections (4 female + 2 male; next to buttons) for easy connection with the popular Grove brick modules
  • extra connection for external LCD backlight and buzzer control
This picture shows you the changes on the upper pcb side

Modding an LCD1602 I2C/IIC Adapter Board to enable external PWM LCD backlight control

A big disadvantage of prototyping with LCD1602 character LCD displays is the amount of I/0-pins you need. Of course you can make use of the 4-bit control mode instead of the 8-bit, but you stil need at least 7 I/O-pins.

It's a better idea to use a cheap IIC/I2C adapter board. This enables you to control an LCD (including the backlight) with only 2 I/O pins (SDA & SCL).

You can find these cheap boards for example at DX.com.

These adapter boards contain a transitor driver to control the LCD backlight. The transistor base is driven by an I/O-pin of the onboard PCF8574. This works great to enable or disable the backlight, but it's "on" or "off". Dimming is not possible because the PCF8574 does not support PWM output.

For prototyping purposes I decided to use an external transitor driver on my Arduino Proto Shield.
Via jumpers I can choose what I want: ON/OFF (standard setting) via I2C or Dimmable via external PWM. This is how I did it.