PLEASE NOTE: This article is obsolete or related to a discontinued product.

Daisy-24 - Front panel LCD with push buttons

Daisy-24 is a mini I2C terminal which mounts a Winstar alphanumeric 16x2 chars LCD module and 4 push buttons.

DAISY-24 can be soldered directly on the Terra Board PCB and used as its front panel display or plugged on a Daisy connector.

When soldered on the Terra board the flat cable is not required because all the signals are both on PCB pads (see below) and on Daisy connector.

If the flat cable is used an insertion key on the connector ensures to plug it in the right way.

Suitable Daisy connectors

This is the list of suitable Daisy connectors where are available the I2C bus signals to use with DAISY-24 module:

Board Daisy connector
TERRA and TERRA-M D10
TERRA and TERRA-M D13
TERRA and TERRA-M D16
TERRA D17
FOXG20 + DAISY-1 D1
FOXG20 + DAISY-1 D6
FOXG20 + DAISY-1 D8

If you are using and Arietta G25 the pin to use on J4 are:

Signal Description Arietta Pin # Daisy 24 pin
3V3 Power out 3.3 volt DC J4.5 3V3
SDA0 Data line bus 0 J4.14 SDA
SCL0 Clock line bus 0 J4.12 SCL
GND Ground J4.9 GND

it is possible also to use the second I2C bus available on these pin

Signal Description Arietta Pin # Daisy 24 pin
3V3 Power out 3.3 volt DC J4.5 3V3
SDA1 Data line bus 1 J4.39 SDA
SCL1 Clock line bus 1 J4.37 SCL
GND Ground J4.9 GND

Code examples

Troubleshootings

The DAISY-24 uses two I2C addresses on I2C bus 0. One for the LCD and another one for the I2C I/O expander used to read the four push buttons and turn on the LCD backlight

The LCD address is fixed at 0x3E.

The I/O expander I2C address usually is 0x27 but could change to 0x3F for some batch of DAISY-24 which using a different chip version as listed below:

Chip mounted I2C address How to use the ablib class
PCF8574T 0x27 ablib.Daisy24()
PCF8574AT 0x3F ablib.Daisy24(exp_address=0x27)


It is possible to probe which is the address used with the existI2Cdevice function available in ablib.py as shown in this example:

hello.py

Related links