Monthly Archives: July 2020

All Electronics LCD-101 (256×128 LCD) with Arduino – Part 2

I posted about the All Electronics LCD-101 display in February 2018. The other day, I noticed that they were back in stock, so I decided to dust off where I last left off with the display. I had designed an I2C backpack with a contrast voltage driver for the display and modified the test Arduino code that I had to work with the backpack. The code was incomplete, so I needed to pick up where I left off, start over, or look at extending another library. I did look at the U8g2 library (https://github.com/olikraus/U8g2_Arduino) but it does not work well with the display. It may be because it is expecting the display to be 240 x 128 rather than 256 x 128.

LCD Pins

Pin No. Symbol Level Function JP2 Pin I2C bit
1 FG 0V Frame Ground 1 N/A
2 Vss(Gnd) 0V Ground 1 N/A
3 Vdd(Vcc) +5V Power supply voltage for logic and LCD 2 N/A
4 Vo Operating voltage for LCD (variable) N/A N/A
5 /RES H/L Reset signal 3 A0
6 /RD H/L Read signal 4 A1
7 /WR H/L Write signal 5 A2
8 /CS H/L Chip select signal 6 A3
9 A0 H/L Data type select signal 7 A4
10 DB0 H/L Display data bit 0 8 B0
11 DB1 H/L Display data bit 1 9 B1
12 DB2 H/L Display data bit 2 10 B2
13 DB3 H/L Display data bit 3 11 B3
14 DB4 H/L Display data bit 4 12 B4
15 DB5 H/L Display data bit 5 13 B5
16 DB6 H/L Display data bit 6 14 B6
17 DB7 H/L Display data bit 7 15 B7

 

A0 /CS /WR /RD /RES
I2C A4 I2C A3 I2C A2 I2C A1 I2C A0 Binary MASK HEX Decimal Valid Op Valid Result Function/Note
X X X X 0 11110 0x1E 30 OR 11110 Reset
X 0 0 0 1 01111 0x0F 15 AND 00001 Invalid State
X 0 1 1 1 01111 0x0F 15 AND 00111 No Operation
X 1 X X 1 01001 0x09 9 AND 01001 No Operation
0 0 0 1 1 00011 0x03 3 EQUAL/XOR 00011 Display data and parameter write
0 0 1 0 1 00101 0x05 5 EQUAL/XOR 00101 Status flag read
1 0 0 1 1 10011 0x13 19 EQUAL/XOR 10011 Command write
1 0 1 0 1 10101 0x15 21 EQUAL/XOR 10101 Display data and cursor address read

 

 

A0 /CS /WR /RD /RES Mask Valid Result
A4 A3 A2 A1 A0 Binary HEX Decimal Valid Op Binary HEX Decimal Function/Note
X X X X 0 11110 0x1E 30 OR 11110 0x1E 30 Reset
X 0 0 0 1 01111 0x0F 15 AND 00001 0x01 1 Invalid State
X 0 1 1 1 01111 0x0F 15 AND 00111 0x07 7 No Operation
X 1 X X 1 01001 0x09 9 AND 01001 0x09 9 No Operation
0 0 0 1 1 00011 0x03 3 EQUAL/XOR 00011 0x03 3 Display data and parameter write
0 0 1 0 1 00101 0x05 5 EQUAL/XOR 00101 0x05 5 Status flag read
1 0 0 1 1 10011 0x13 19 EQUAL/XOR 10011 0x13 19 Command write
1 0 1 0 1 10101 0x15 21 EQUAL/XOR 10101 0x15 21 Display data and cursor address read

 

12 June 2022 Update

I had a question about this display, so I have updated the GitLab repository at https://gitlab.com/richteel/LCD-101/ to include the I2C Backpack that I designed for the LCD with a negative charge pump for the contrast and I2C or SPI interface for Arduino and Raspberry Pi. You may order the black PCB from Oshpark at https://oshpark.com/shared_projects/LwLCCjaW.

The schematic for the backpack is in the LCD-101/LCD-101 2020/I2C Backpack folder and is named I2C Backpack.pdf.