GLK19264-7T-1U and RS232 (TTL levels) communication

[dor]

Hi,

I have the GLK19264-7T-1U device.

There's a communication problem with the device. It turns ON, but it seems that it doesn't detect the bits that I'm sending.

I did the following configurations:

1. Disconnected all 3 zero-ohm resistors from the RS232 jumpers,
   and connected 2 zero-ohm resistors to the TTL jumpers.
2. Then, I connected wires to the "Power/Data Connector".
   Pin 1 - Power
   Pin 2 - RS232 Rx (connected to UART Rx)
   Pin 3 - RS232 Tx (connected to UART Tx)
   Pin 4 - GND
3. Configured UART to work as following:
   • Character Length - 8 bit
   • NO parity bits. (they do NOT exists while communicating)
   • baud rate = 19.2 kbps
   • 1 start bit and 1 stop bit.
   • The LSb (Least Significant bit) is sent first.

But it didn't work at all.
The display turns ON, but there is NO communication.

My micro-controller can send up to 3.3v at i/o pins, but that must be detectable by the GLK19264-7T-1U device, because that's a legal TTL '1' logic level voltage.

Also, I tried to supply 5v or 3v to the Power pin (pin 4). None worked.

While writing this message I started to get the feeling that maybe I need to switch between the Rx & Tx pins of the Power/Data connector... Maybe that's the problem?

Anyway, I also wanted to note that the datasheet doesn't mention enough details about the RS232 communication, regarding the parity bit, start/stop bits, legal logic levels voltage etc.

Moreover, some tips about reducing power consumption would be MUCH helpful for me - my power supply is a battery (with approx. capacity of 0.5mAH)...

Thank you!

Best regards,

[Raquel]

Hi,

Thank you for posting on the forum.

If you have a GLK19264-7T-1U, you should be powering it with 5V.
If you have a GLK19264-7T-1U-LV, you should be powering it with 3.3V.

How did the swapping of RX and TX go? I am thinking that would be the culprit for not communicating.

You have the configuration correct: 8,n,1, 19200 baud.

Best Regards,