SDI-12 Slave

Hello,

I’m trying to create an I2C PH sensor over a SDI-12 bus.

I’m using a Arduino Leonardo to read sensor data over I2C and then send it to the datalogger over a SDI-12 bus.

I have a DIY datalogger using same SDI-12 library, with a commercial sensor with address 0 working without problems, and my PH sensor, I just run the example there is the folder ‘example/h_SDI-12_slave_implementation’ with some lines commented, just to verify the comunication. So, I just left the part where data is available and just print the incomming char… but nothing appears, even I’m getting data from sensor 0 from datalogger. I checked with an oscilloscope and there is imcomming signal on pin 7 of my leonardo. I serialprinted the variable avail on the loop and it is always 0, menaing there is no data comming.

I guess I’m missing something… but for the moment not clear what it can be.

Here the code:

#include <Arduino.h>
#include <SDI12.h>

#define DATA_PIN 7 /*!< The pin of the SDI-12 data bus */
// Create object by which to communicate with the SDI-12 bus on SDIPIN
SDI12 slaveSDI12(DATA_PIN);

void setup() {
Serial.begin(115200);
slaveSDI12.begin(DATA_PIN);
delay(500);
slaveSDI12.forceListen(); // sets SDIPIN as input to prepare for incoming message
pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
// If a byte is available, an SDI message is queued up. Read in the entire message
// before proceding. It may be more robust to add a single character per loop()
// iteration to a static char buffer; however, the SDI-12 spec requires a precise
// response time, and this method is invariant to the remaining loop() contents.
int avail = slaveSDI12.available();
Serial.println(avail);
if (avail < 0) {
slaveSDI12.clearBuffer();
} // Buffer is full; clear
else {
for (int a = 0; a < avail; a++) {
char charReceived = slaveSDI12.read();
Serial.print(charReceived);
}
}
}

I think the code above should work as sniffer for the SDI-12 bus… so getting data is running on the bus.
I even tried to blink the LED with data over DATA_PIN, and the leds blinks… so leonardo is reading the incomming signal.
I also tried with arduino MINI PRO 5V 16MHz, and the same result.
I hope you can help me about this issue.
If you need more information and details to find the issue: just ask me.
Thank you.
BR,
daniel