Author Topic: NHD‐0420CW‐AB3 I2C Interface  (Read 7230 times)


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NHD‐0420CW‐AB3 I2C Interface
« on: January 22, 2015, 04:13:55 PM »
I don't understand exactly how to send data and/or control bytes to the NHD‐0420CW‐AB3 display (US2066 driver).

Please verify if this is correct. In each case the start condition and slave address have been sent to the display.

1. To send data only: Send a control byte with both Co and D/C# set to zero (0x00). Any subsequent bytes will be interpreted as data.

2. To send a command: Send a control byte with Co set to one and D/C# set to zero (0x80). The following byte will be interpreted as a command. Repeat for each command (i.e. always send both a control and a command byte).

3. Alternatively, data can also be sent by sending a control byte with Co set to one and D/C# set to one (0xC0). The following byte will be interpreted as data. Repeat for each data byte (i.e. always send both a control and a data byte).


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Re: NHD‐0420CW‐AB3 I2C Interface
« Reply #1 on: January 23, 2015, 10:00:06 AM »
Perhaps the below code snippets will better assist you:

Code: [Select]
const char slave2w = 0x3C;

void send_packet(unsigned char x)
  unsigned char ix;

void command(unsigned char c)
      tx_packet[0] = 0x00;
      tx_packet[1] = c;

void data(unsigned char d)
      tx_packet[0] = 0x40;
      tx_packet[1] = d;


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