I'm getting a strange issue. We have a Atmega 128 controller board that kee ps on polling 15 Atmega8 based ultrasonic sensors. They are connected in RS 422 model where all Tx pins of 15 sensors are connected together and in-tu rn connected to the Rx of the Atmega 128 controller and all Rx pins of 15 s ensors are connected together and finally connected to the Atmega 128..
Am making sure that the communication protocol is implemented correctly.. I mean.. no data collision among the sensors.. enabling and disabling Tx/Rx links property while exchanging the messages....
The problem is.. when I saw the output through the UART on the Atmeg128 con troller, the output looks fine.. it is keeping on polling and I saw the bel ow polling message...
01P 02P ......15PMeaning 01 sensor.. what is the status..., 02 sensor what's the status ..? etc.. and sensors are also properly responding..
But when I checked on the next day, either none of them are working or few of them got frozen.
When I checked the same UART data,.. I found some scrap message or sometime s no UART data at all...
And sometimes though Atmega 128 is polling fine, Atmega 8 is not at all res ponding.. it is mute..
No loose contacts ...
Why so?
There's watchdog timer running in all Atmega8 and atmega128 also..
What are the typical causes for this strange issue?
Power supply is a 12V dc , meanwhile brand...