Help Using Serial Monitor with a BLE Component

Projects Programming
1

Hi everyone! Arduinoob here.

I'm working with an Arduino nano clone (ATmega328P microprocessor, TI CC2540 BLE 2.4G BLE component) that has pretty good documentation, but I've gotten stuck.

Specifically, I'm having trouble programmatically interacting with the Bluetooth Low Energy (BLE) component it came pre-installed with. I followed the documentation and successfully interacted with the BLE chip by issuing AT commands via the IDE serial monitor. The test case is as follows:

  • Open the serial monitor
  • Set line endings to "Both NL & CR"
  • Enter "AT" as a message payload
  • Click "Send"
  • Result: receive "+OK" from the BLE component

I have successfully performed that test and other AT commands via the IDE serial monitor, but whenever I try to interact with the BLE chip via the program code I have no such luck.

I started with this rudimentary attempt at posting the "AT" test:

void setup() {
  Serial.begin(9600);
  Serial.write("OPENED SERIAL\n");
  Serial.write("AT\r\n");
}

void loop() {
  while(Serial.available() > 0){
        Serial.write(Serial.read());
    }
}

However that code simply resulted in posting the "AT" to the serial monitor output, not interacting with the BLE chip. I concluded that I was passing data from the microprocessor straight off of the hardware, and maybe needed to send data to the serial monitor from a different source.

Here was my next attempt, using a software serial to write "AT" to the main onboard serial:

#include <SoftwareSerial.h>
#define BLUETOOTH_RX 0
#define BLUETOOTH_TX 7 
 
SoftwareSerial BTIN = SoftwareSerial(BLUETOOTH_RX, BLUETOOTH_TX);

void setup() {
  pinMode(BLUETOOTH_RX, INPUT);
  pinMode(BLUETOOTH_TX, OUTPUT);

  Serial.begin(9600);
  while(! Serial);
  BTIN.begin(9600);
  while(! BTIN);
  Serial.write("OPENED SERIAL\n");
  BTIN.write("AT\r\n");
}

void loop() {
  while(Serial.available() > 0){
        Serial.write(Serial.read());
    }
}
}

However, this code similarly just posted out "AT" to the IDE monitor. I tried every permutation of write and print commands with \r\n, \r, \n, etc., all to no avail.

Is there something I'm missing or haven't tried regarding how data is transferred from IDE serial monitor to the onboard serial compared to writing/printing programmatically to the serial? I'm at a loss of how to proceed any further, since the documentation provides no insight into how data flows from microprocessor to BLE chip aside from the IDE serial monitor, which is not acceptable for my project.

Thank you very much for your time!

-Iconn

2

iconn1793:
that has pretty good documentation, but I've gotten stuck.

Maybe "pretty good" compared to other garbage Chinese products, but the fact they don't bother to document how the BLE chip is connected to the ATmega328P makes the documentation absolute garbage as far as I'm concerned.

Without that information, you're just going to be going on pure guess work to get any communication working. You can try contacting the company to get the information or you may be able to look really closely at the board and follow the traces to see the connection, or you could just toss the piece of junk and buy something better from a company that actually cares about their customers.

iconn1793:
Here was my next attempt, using a software serial to write "AT" to the main onboard serial:

void setup() {

//setup SoftwareSerial BTIN

Serial.begin(9600);
  while(! Serial);
  BTIN.begin(9600);
  while(! BTIN);
  Serial.write("OPENED SERIAL\n");
  BTIN.write("AT\r\n");
}

void loop() {
  while(Serial.available() > 0){
        Serial.write(Serial.read());
    }
}

That code won't even compile. If you want help, you need to post the full sketch.

3

Hi Pert,

Thanks for the reply, I updated the code snippet above.

I agree its a bit frustrating but theoretically if I can use it fine from the IDE serial monitor then I should be able to programmatically right? Is there something foundational I'm missing about how the IDE serial monitor works vs a programmatic serial monitor?