I am having serial communication issues with my M6E Nano (SEN-14066) board. I am using it as a shield on the red Sparkfun Uno board (DEV-13975) with the external antenna (WRL-14131), interface cables (WRL-00662 & CAB-14132), and an external power supply (TOL-15312) to the Uno board. I am running the Example1_Constant_Read sketch. The only way a can get it to work is to consecutively turn the power supply, plug the USB cable into the computer and then start the Serial Monitor. This will work only for a minute or two and then quit working. It wont work again until I turn the power off and start over. Any help is appreciated. Thanks!
Could you possibly share a photo of your set-up, and perhaps a wiring diagram/description?
In the meantime, try using a different USB cable, and maybe try swapping the HW/SW UART switch - instructions for hooking up the M6E https://learn.sparkfun.com/tutorials/si … e-overview also mentions:
JP1
A jumper on the rear of the board labeled JP1 is closed by default allowing the board to be powered via the USB to Serial converter.
Rear JP1 Jumper
JP1 Jumper
By default the JP1 Jumper is closed allowing the USB to Serial converter provide power to the SRTR. Cut this jumper if you are powering the board with a LiPo battery or other external power supply. This will isolate the USB to Serial converter for communication only.
So, it sounds like you may need to open that JP1 jumper (cut it) to use USB for serial with an external power supply.
Hope this helps!
the M6E is very known to be very sensitive to enough power. Hence the advice is NOT to increase beyond 500dBm and even then… What you experience is what I often had. I always connect an extra power source to the M6E directly, using the 3.7V - 5V separate pins. Most of the time a charged lipo battery as the M6E needs an external supply that can handle bursts directly to the Nano. Connecting an external supply to the UNO does not really help a lot. The UNO on-board regulator has limited output power and limited capacitors.