The SparkFun LTE GNSS Breakout - SARA-R5 does not respond on the USB-C lines in any way.
No welcome message on boot, no response to AT.
The using the UBLOX B-Center (via Virtual Box) I get a message saying “no response”.
The LEDs for “On” (white), 3.3V (red), and VIN (yellow) light up.
The RX/TX LED’s never blink.
Power from Macbook Pro USB port (both directly and via a non-powered hub).
I tried all of the USB-C ports on the device: the first two provide a pseudo-serial port I can connect to. I used 9600 baud.
Tried two different USB-C cables (including USB-C to hub, to USB-2 cable with USB-C adaptor).
Tried pushing both reset pins on the device in various sequences.
Tried with and without antennas connected, with and without the SIM card inserted.
Also tried “AT” follows by either CTRL-M, CTRL-J.
I should add that based on some UBLOX material, I would expect a “welcome” message of some kind on boot. I would expect to see the RX line flashing at that point, irrespective of any connected device. I don’t see that.
My bad: RX flickers faintly. I ran though all reasonable baud rates under program control and as the room got dark I could see it flickering. It’s faint.
I tried all three USB connectors. Only the first two (left and middle) provided serial connections.
I used Mac OSX and also tried a Windows Emulator under Virtual Box. In both cases I was able to connect to the CH340. On Windows it was COM1, but that was mapped to the OSX serial device /dev/tty.usbserial-143230. FYI, Also also tried an older machine without a CH340 driven, by the way, so I know what that scenario looks like.
As noted above I used all "reasonable"serial speeds including 9600,19200,4800,57600,115200,38400,300, 1200, 2400,9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600 (in that order, note some tried repeatedly). This includes all know speeds mentioned in the UBlox SARA-5 documentation.
What does it mean to be “turned on”? There is no on/off switch I am aware of. It was plugged into a power USB port. The LED’s lit up and the network connection LED (NI) lit up after a minute or two. I also tried the reset buttons.
Unfortunately I don’t have one of these handy to try out for you but here’s what I’ve learned from the person that wrote the tutorial.
There’s no welcome message when the board boots up.
The SARA-R5 should be on at powerup. (The SARA-R4 required you to press a button to turn it on, that’s why I was asking about turning the board on.) You can force the board to power on by holding the SARA On button for 3 seconds. (Might be worth a try.)
By default, the only USB connector that works is the center USB connector labeled UART 1 and the baud rate should be 115200.
I’m not exactly sure what line ending the module is looking for, you will need to experiment with different combinations of CR and LF to see what makes it happy.
Make sure your terminal emulator program is set to send a carriage return only when you press the enter key. If it’s sending extra bits, the SARA-R5 might be ignoring the entire command you’re sending.
It’s a good idea, however, I already tried only \r, only \n, \r\n, and \n\r manually. I also did that under program control at all those various baud rates.