Day: November 24, 2018

How to use a JLX1602G-390 display with NuttX

I just created a driver for NuttX to use JLX1602G-390 display.

This display is based on Siatronix ST7032i the I2C version.

First you need to wire it connecting an external capacitor and a resistor as explained on this schematic:

I am using the STM32F4Discovery board with this display connecting pins PB6 to SCL and PB9 to SDA. These pins are configured to enable an internal pull-up resistor, but case your microcontroller doesn’t have it, you need to connect external pull-up 4k7 resistors to SCL and SDA pins.

After configuring the NuttX to use this display, you can execute the slcd command from NuttShell:

nsh> slcd
Opening /dev/disp0 for read/write access
Attributes:
  rows: 2 columns: 16 nbars: 0
  max contrast: 0 max brightness: 1
Clear screen
WRITING:
0000: 1b5b46                                                            .[F 
Set brightness to 1
Print [Hello World NuttX]
WRITING:
0000: 48656c6c6f20576f726c64204e757474 58                               Hello World Nutt X
Test complete
nsh> 

You can see the step-by-step video tutorial here:

Source of this schematic: https://bitbucket.org/ospringauf/mecanumrover/wiki/JLX1602G-390