- Set (A) Arduino UNO R3 + RFM69HW 915Mhz
- Set (B) Arduino UNO R3 + RFM69HW 915Mhz
Testing code:
Working scenario with both testing code:
- Set A & B are connected to 2 different USB port of same PC
- Set A connect with USB cable to PC and set B 5v and ground connected to Set A
Not working scenario with both testing code:
- Set A and B (either one or both) connected to my laptop not working and RFM69HW is over heating.
- Set A connected to PC and Set B connect to wall out let with a USB power supply (5V, 2A) not working
Can someone explain me if this is power issue or something else? if power issue then what is the power adapter requirement?
How are you dealing with the 5V to 3.3V interface problem?
I am directly connecting the RFM69HW module to arduino 3.3v pin. Do I need to connect something in between? and what is that? And also someone please explain me the reason for the same?
Sorry for too many questions.
You cannot connect 5V input/output pins from an UNO to the 3.3 V input/output pins of the RFM69HW module. Doing so would be the cause of the overheating that you mentioned. The RF module is almost certainly dead.
For your next attempt, with a new RF module, the easiest method is to use 5V-3.3V bidirectional level shifters in between the two, as described here: Bi-Directional Logic Level Converter Hookup Guide - SparkFun Learn
There are other approaches.
Hi jremington,
Thanks a lot for the explanation.
What is shown there is a 4Ch bi-directional-logic-level-converter. From Arduino (5v, 3.3v, D10-D13 will connect to the LLC. But what about the DI00(RFM) pin which connects to D2 (Arduino)?. Should it be directly connected to Arduino?
Should it be directly connected to Arduino?
If you are using a connection as an INPUT to the Arduino, the connection can be direct.
Outputs FROM the Arduino are the problem. Google "5v to 3.3V interfacing" for more information.
Note: you may have damaged one or more output pins of the Arduino as well.