BerryGPS-IMU v4 No signal

[digitaltopo]

Hi there, hope you are well. Thanks for this great module!

I’m trying to setup and test out the GPS on a Raspberry Pi Zero 2 W (Running latest Raspberry Pi OS), but not seeing any output from cat dev/serial0 or any of the other gps related commands from the BerryGPS tutorial. There are no NMEA sentences available.

On the unit itself, there is one green led on just above the left QWIIC connector, but no other lights seem to be happening.

I would appreciate any guidance on how to troubleshoot this. Thank you!

[Mark Williams]

How do you have the BerryGPS-IMU connected?  is it sitting on top of the Raspberry PI GPIO?

Mark --OzzMaker.com --

[digitaltopo]

Yes, it’s connected via GPIO pins, on top of Pi Zero.

[Mark Williams]

Can you please show the output of these commands;

<strong>dmesg | grep tty</strong>

<strong>stty -a -F /dev/serial0</strong>

<strong>grep uart /boot/config.txt</strong>
 

Mark --OzzMaker.com --

[digitaltopo]

$ dmesg | grep tty:

[ 0.000000] Kernel command line: coherent_pool=1M 8250.nr_uarts=1 snd_bcm2835.enable_compat_alsa=0 snd_bcm2835.enable_hdmi=1 bcm2708_fb.fbwidth=480 bcm2708_fb.fbheight=640 bcm2708_fb.fbswap=1 smsc95xx.macaddr=B8:27:EB:DB:94:CB vc_mem.mem_base=0x1ec00000 vc_mem.mem_size=0x20000000 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait fbcon=map:10 fbcon=font:ProFont6x11
[ 0.001264] printk: console [tty1] enabled
[ 3.237658] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 114, base_baud = 0) is a PL011 rev2
[ 3.255236] 3f215040.serial: ttyS0 at MMIO 0x3f215040 (irq = 86, base_baud = 50000000) is a 16550
[ 6.006399] systemd[1]: Created slice system-getty.slice.
[ 40.405065] input: Kano keyboard Keyboard as /devices/platform/soc/3f201000.serial/tty/ttyAMA0/hci0/hci0:11/0005:0A5C:8502.0001/input/input1
[ 40.406484] input: Kano keyboard Mouse as /devices/platform/soc/3f201000.serial/tty/ttyAMA0/hci0/hci0:11/0005:0A5C:8502.0001/input/input2

$ stty -a -F /dev/serial0:

speed 9600 baud; rows 0; columns 0; line = 0;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;
-parenb -parodd -cmspar cs8 hupcl -cstopb cread clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff
-iuclc -ixany -imaxbel -iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt
echoctl echoke -flusho -extproc

$ grep uart /boot/config.txt:

enable_uart=1

[digitaltopo]

Hi just following up, any thoughts on how to troubleshoot? Thank you!

[Mark Williams]

Sorry for the delay.
Do you have any jumper cables? It would be good to do a loopback test on the serial port, connect TX to RX. Open it with minicom, everything you type should be echoed back. Some more info here;

Can you also take a photo of the top half of the BerryGPS-IMU and upload it here. In the past, we have had components been knocked off

Mark --OzzMaker.com --

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