SparkFun Forums 

Where electronics enthusiasts find answers.

By awrestuc
Hello all,

I am having trouble with the Simultaneous RFID Reader - M6E Nano reader card.

I have managed to connect an external antenna and read the data on a Raspberry Pi 3B. I get temperature readings on a regular basis and read tags at quite a distance from the antenna (15 to 20 feet). When it works, it works great!

My issue is that after some time, the reader simply stops sending data to the Pi. The amount of time varies, sometimes as little as 30 minutes, other times as long as 4 hours. When this happens, the amber light on the Serial Breakout board stops blinking and the Pi does not read any data. However, if I simply cycle the power on the Nano, everything works almost immediately. This leads me to believe that it's an issue w/ the reader, not w/ the Pi.

I have 4 of these units, and they all behave the same way.

Full specs:
Reader - SparkFun Simultaneous RFID Reader - M6E Nano -
Communication to Pi - SparkFun Serial Basic Breakout - CH340G -
Power hookup - Screw Terminal to SparkFun microB USB Breakout -
Battery - 22000mah LIPO - Up to 5.8A - ... 07QRQ5HZ4/

Reader specifics:
Serial Selection Switch - Set to HW-UART, though it does not seem to matter as reader is connected to a Serial Breakout, which is then connected to the Pi via USB cable.
JP1 - This is cut so that the only power coming into the reader is from the battery or wall outlet.
Heat Sinks - Two heat sinks.
My first thought was that perhaps the temperature was too high. However, I am able to log the temperature readings, and the temperature never gets anywhere near it's safety threshold.

My next thought was that perhaps the battery that is powering the board was not providing consistent power. To test this, I plugged the reader directly into the wall, and it still eventually cuts out in approximately the same time frame.

My questions are:
Has anyone experienced this type of behavior?
What else should I be testing?

Any help would be greatly appreciated, as I have spent an embarrassing amount of time trying to troubleshoot this issue.
You do not have the required permissions to view the files attached to this post.
By paulvha
The nano is extremely sensitive to power availability. I also power with a 2200maH battery... but kept the JP1 closed and even then .. when I run at high raeding/writting power it will fail often intermittently. Putting a scope on the data lines, I can only see a high amount of rubbish. Try running (even for test) on lower power. In my case it does run without problems. You will need a power supply that can provide high burst-level power (something with large capacitor)