Tag Archives: i2c

Tasmota: Connect a lcdproc/LCDd compatible HD44780 i2c Display

Hi,

I already owned a HD44780 I2C Display, which is compatible to LCDd/lcdproc, and want to get this running with Tasmota.

Problem: The LCD 2004 or LCD 1602 Display, for which the Tasmota LCD driver was written, uses a different wiring between the i2c expander (PCF8574) and the HD44780 Display.
Continue reading Tasmota: Connect a lcdproc/LCDd compatible HD44780 i2c Display

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Linux: Enable i2c kernel tracing

Hi,

when you want to see whats happened on the i2c bus on an raspberry pi you can enable tracing with debugfs.

Get root and mount debugfs. This is usually already mounted in raspbian

michael@debdev ~ # sudo su
root@debdev ~ # mount -t debugfs none /sys/kernel/debug

Continue reading Linux: Enable i2c kernel tracing

Raspberry PI: Connecting a HD44780 Display over I2C Bus

Hi everybody,

some application, i.e. XBMC can show informations on a display by using LCDproc as driver.

This post describes a way to connect a HD44780 display to a Raspberry PI  by i2c bus.

Let’s start with the physical layer. This is the overview schematic on how to connect the display to a Raspberry PI.

Connecting a hd44780 Display with Raspberry PI
Connecting a hd44780 Display with Raspberry PI

Based on these I developed small board with a 6 Pin header which is Pin compatible to the Raspberry PI. So a simple 6 pole ribbon cable can be used to connect the HD44780 Display to the fruit.
Here is my PCB. First the schematic.

Board schematic
Board schematic

and my board layout. Unfortunately there are a lot HD44780 models available and the location and the direction of the pins are different, so you have to adapt the layout to the specification of your display.
Continue reading Raspberry PI: Connecting a HD44780 Display over I2C Bus