Lcd display

[pratikkhandelwal]

Hey dan,

where can i get connections to the lcd display. what type of lcd display can be used?

[draggaj]

Hey dan,

where can i get connections to the lcd display. what type of lcd display can be used?

from the plug in,
PCF8574 = 0x20-0x27
PCF8574A = 0x38-0x3F

search for PCF8574 or PCF8574A relating to an i2C bus based 16x2 LCD.
Most appear to be HD44780 based LCD (16x2 chrs) with an I2C adaptor connected to them..

i2C means only a couple of GPIO pins are required, otherwise you need a lot more, I think up to 8.

I'm looking to purchase an LCD myself,, hundreds out there

bob

[pratikkhandelwal]

Hey dan,

where can i get connections to the lcd display. what type of lcd display can be used?

from the plug in,
PCF8574 = 0x20-0x27
PCF8574A = 0x38-0x3F

search for PCF8574 or PCF8574A relating to an i2C bus based 16x2 LCD.
Most appear to be HD44780 based LCD (16x2 chrs) with an I2C adaptor connected to them..

i2C means only a couple of GPIO pins are required, otherwise you need a lot more, I think up to 8.

I'm looking to purchase an LCD myself,, hundreds out there

bob

Can you provide connection diagram of raspberry pi with lcd display in detail with circuit diagram and components?

[draggaj]

Hey dan,

where can i get connections to the lcd display. what type of lcd display can be used?

No diagram as its only its 4 wires if you use one of these....
https://tronixlabs.com.au/display/lcd/se...australia/
coupled to one of these.....
https://tronixlabs.com.au/display/lcd/ch...interface/
or equivalent. adafruit have similar....in fact these may be same as adafruit sell....
in Australia, these are less than $10 for the pair...

anyhow, for my RPi B series, I connected the i2C backpack as follows
Backpack Pin-----------RPi Pin (physical Pin)
Grnd---------------------14 (Grnd)
Vcc-----------------------04 (+5v)
SDA----------------------03 (SDA1)
SCL-----------------------05 (SCL1)

NOTE - there is a bug with the LCD library at the moment preventing LCD from working on SIP. I got it to work, but a library is missing from github and I am working with Dan directly on that.

Also the i2c backpack above (and possibly the adafruit equivalent) uses address 03f by default (its changeable via solder bridge) and depending on RPi vintage smbus port 1 (later RPi) or 0 (earlier RPi). There are i2c tools available to correctly detect and report the address an i2c device is using.

I'll post a bit more once I have the wrinkles ironed out and Dan comes back to me...
Bob

Can you provide connection diagram of raspberry pi with lcd display in detail with circuit diagram and components?

[pratikkhandelwal]

Hey dan,

where can i get connections to the lcd display. what type of lcd display can be used?

No diagram as its only its 4 wires if you use one of these....
https://tronixlabs.com.au/display/lcd/se...australia/
coupled to one of these.....
https://tronixlabs.com.au/display/lcd/ch...interface/
or equivalent. adafruit have similar....in fact these may be same as adafruit sell....
in Australia, these are less than $10 for the pair...

anyhow, for my RPi B series, I connected the i2C backpack as follows
Backpack Pin-----------RPi Pin (physical Pin)
Grnd---------------------14 (Grnd)
Vcc-----------------------04 (+5v)
SDA----------------------03 (SDA1)
SCL-----------------------05 (SCL1)

NOTE - there is a bug with the LCD library at the moment preventing LCD from working on SIP. I got it to work, but a library is missing from github and I am working with Dan directly on that.

Also the i2c backpack above (and possibly the adafruit equivalent) uses address 03f by default (its changeable via solder bridge) and depending on RPi vintage smbus port 1 (later RPi) or 0 (earlier RPi). There are i2c tools available to correctly detect and report the address an i2c device is using.

I'll post a bit more once I have the wrinkles ironed out and Dan comes back to me...
Bob

yes provide me an update once lcd is working with sip.

[dan]

An updated version of the lcd_adj plugin is now in the plugins repository.
You just need to re-install to get the update.

[pratikkhandelwal]

An updated version of the lcd_adj plugin is now in the plugins repository.
You just need to re-install to get the update.

Thanks for the update but still no data is not displayed on my lcd display. I have connected it according to the connections shown above. It is detecting i2c and giving address 3f. But no data is displayed. Looking for a solution to the problem

[dan]

An updated version of the lcd_adj plugin is now in the plugins repository.
You just need to re-install to get the update.

Thanks for the update but still no data is not displayed on my lcd display. I have connected it according to the connections shown above. It is detecting i2c and giving address 3f. But no data is displayed. Looking for a solution to the problem

Depending on the type of i2c adapter you are using you may need to add a level shifter to boost the output voltage from the Pi to 5V.