Issues with Arduino Leonardo / Bluesmirf Sparkfun tutorial

Wireless & IoT Bluetooth
1

I realize that this tutorial is a bit old, but I am trying to follow it verbatim and am having issues at the “Using GET Commands” Step. I am able to set it into command mode from the Arduino Serial Monitor by typing in the ‘$$$’ command, but the monitor doesn’t return a response from the module. Wiring is very simple and I have checked it several times to make sure Rx and Tx pins are mapped properly. I am using an Arduino Leonardo. Any reason why the monitor will not return any values?

Here is the tutorial that I am using:

https://learn.sparkfun.com/tutorials/us … esmirf/all

I have the silver edition of the Bluesmirf

Thanks for the help.

2

Hi VantageReloading,

Most likely the issue is due to the limitations of the [Software Serial Library. Only specific pins on the Leonardo work for change interrupts so try switching to one of the pins listed in the link above for RX and that should fix the issue. You can still use any digital I/O pin for TX.](https://www.arduino.cc/en/Reference/softwareSerial)

3

Thanks for the reply Mark. I tried following the instructions in the library that you listed and remapped the Pins to 8 and 9 for RX and TX Respectively, and still the same result - the console doesn’t print any results from the bluetooth module. The LED indicator light does however go into command mode when I enter “$$$” but I have no read out response in the console to denote that it is in CMD. Totally Bizzare.

The only lines in code that I replaced were lines 14-15 to take into account the new pins used per the documentation listed.

int bluetoothTx = 9; // TX-O pin of bluetooth mate, Originally mapped to Arduino D2

int bluetoothRx = 8 ; // RX-I pin of bluetooth mate, Originally mapped to Arduino D3

Any other ideas?

Thanks!

4

Hmm, have you made sure to set the Serial Monitor initially to “No Line Ending” prior to entering Command Mode and then switching to “Newline” once you have sent the “$$$” command? Similarly, is your baud rate set to 9600 for the Serial Monitor? If you have made sure both of those settings are correct, my guess is it might be a hardware problem. Can you please take a few photos of your Bluetooth Mate and the circuit you have it in with your Leonardo and attach them to your reply? Please do your best to make sure they are clear and well-lit.

5

Hi Mark,

That is correct - I set the serial Monitor to “No Line Ending” and then switched to “Newline” after sending “$$$” via the Serial Monitor.

I had planned to migrate to the Pro Micro (had a couple on back order from my local electronics shop), so my photos and skitch are updated to reflect that I swapped the Pro Micro in now. I am in the same situation where sending “$$$” causes the RN42 to clearly enter CMD mode as indicated by the red LED flashing 10x/s, but no value is returned to the console.

In troubleshooting, I also tried echoing the Serial Monitor inputs as well as whatever the bluetooth module will send, and I’m seeing my messages truncated to 2 characters. Sending “$$$” returns only “$$”. I’m not sure if this tells anything.

I also tried switching to a different Arduino Pro Micro, and between the Leonardo and the 2 Pro Micros, I think I can at least rule out faulty hardware on those units.

[Here are the pictures of the setup in a one-drive folder](Microsoft OneDrive)

6

Hi again,

Thanks for confirming that information and taking the photos of your circuit. Everything looks just fine here and I would agree that testing with two Pro Micros and the Leonardo rules out a hardware issue with the microcontrollers so I think the issue is most likely related to something on the BlueSMiRF. We would be happy to help you out with a replacement so if you purchased the BlueSMiRF from SparkFun, please fill out the form on [this page and in the “Why do you want an RMA?” box fill in a brief description of the issue and link to this thread. We’ll follow up with further information about that process. If you purchased the BlueSMiRF from one of our distributors, please contact them directly.](Return Policy - SparkFun Electronics)

7

FYI - I was having the exact same problems but changing to pins 8 and 9 (to bluesmirf tx and rx, respectively. That’s reverse from what you tried) did the trick for me.