I have been playing with my RTK Express since I received it last Friday. It has worked fine up until this morning when I looked at the display and the display didn’t make sense (multiple different icons on it). It was still broadcasting via BLE to SW Maps. I powered it down and now the display won’t come on. I have tried pushing the power button and then connecting via BLE but a scan can’t find anything (just in case it is only the display that is bad). It is difficult to put into “config” mode when the display is down for me to check via WiFi. I haven’t connected to it via USB/serial. Any suggestions?
Cross post to here: viewtopic.php?f=116&t=60134&p=243639
Sorry for the hassle! Sounds like you’ve got the device in an odd state. You can force the device off by holding the power button for ~10s. See docs here: https://docs.sparkfun.com/SparkFun_RTK_ … -power-off
It sounds like the display is borked or something else is causing I2C issues. Can you capture the output from the power on sequence from a terminal? It looks something like this:
rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0030,len:1240
load:0x40078000,len:13012
load:0x40080400,len:3648
entry 0x400805f8
Display started
LittleFS Started
ZED-F9R firmware: HPS 1.30
SparkFun RTK Express Plus v3.7
microSD: Online
Profile 'Profile1' loaded
Fuel gauge configuration complete
Batt (97%): Voltage: 4.18V Charging: 3.33%/hr Green
GNSS configuration complete
Accelerometer configuration complete
System time set to: Thursday, September 07 2023 17:03:00
*WIFI_OFF
Bluetooth broadcasting as: Express Plus Rover-5A5A
*NTRIP_CLIENT_OFF
State: Rover - No Fix, 2023-09-07 17:03:01.727
State: Rover - Fix, 2023-09-07 17:03:01.797
Batt (97%): Voltage: 4.18V Charging: 3.33%/hr Green
Rover Accuracy (m): 0.4290, SIV: 27
Rover Accuracy (m): 0.4148, SIV: 27
SD card size: 14.4 GB / Free space: 14.4 GB
Log file name: /SFE_Express_Plus_230907_170305.ubx
Log file size: 389 - Generation rate: 0.1kB/s
The main thing I’m looking for is ‘Display started’ or any errors around that point.
I just posted in the my other post that you linked above that the unit is working now. I powered it down and then back again (after the first successful start) and the display started out with a line or two missing and then became normal in a couple of seconds.
I will try to connect terminal software to the unit just so I can take a look at the output. I was going to download some terminal software when I read the documentation but your documentation listed terminal programs that were out of date (i.e. not for Windows 10, which is what I have). If you can recommend a good Windows 10 terminal program then I will give it a go.
OK. After powering the unit down from the above state, I can’t get it to restart. As soon as a press the power button, my computer recognizes one of the comm ports but within a few seconds the port goes away whether I keep holding the power button on or release it (immediately, pause of 1 second, pause of 2 seconds, pause of 3 seconds, or pause of 4 seconds). Screen never displays. I will try to connect via terminal and get the output that you request once I download terminal software.
Ok, we’ve identified the issue. There was an old batch of stock of the RTK Express that got built in 2021 that used a faulty part. We thought we had gone through the warehouse to fix all the defective units but I’ve been made aware that we missed some. We’re going through the old stock right now and fixing the problem. If you want the nitty gritty electrical engineering details, I’m happy to share, but the unit you have will likely continue to be flaky until we can get the unit back from you for repair.
Thanks for the response. I have requested an RMA. I am hoping that I can return just the RTK Express and not the entire kit but that is up to you guys. Just curious about which part but I don’t need a lot of details.
We’ve seen a >1% failure rate of the accelerometer IC. When it dies, it takes the I2C bus with it causing problems for all the other devices (display, GNSS receiver, fuel gauge, etc). The solution is to remove the accelerometer from the product which is easy enough if you have a hot-air rework station and a pair of tweezers.
I don’t have a hot air rework station although I do have a soldering iron. I was wondering about the accelerometer because I didn’t see any access to it either in the included software or through the display. I will ship it back for repair as soon as I receive my RMA. Thanks for all the help.
Thank you for your patience! We’ll get you fixed up asap.
FedEx tracking says that it is supposed to be delivered to your facility tomorrow. I forgot to remove my 64GB microSD card. It would be nice to get that back also if anyone has a chance to do so. Looking forward to working with the RTK Express again soon.
Finally got my replacement unit today. It came in as V3.6 but I was able to update it to V3.10 via the GUI and a USB cable. I look forward to connecting it to NTRIP server. California has a free correction station located a couple of miles from me so it should be fairly accurate. I am keeping my fingers crossed that this unit will last.
My unit is up and running. Using SW Maps on iOS and the CRTN (California Real Time Network) RTCM, I am getting 0.591" horizontal accuracy and 0.669" vertical accuracy. I will take it to a local benchmark next.
Thanks everyone for the help.
sparky:
We’ve seen a >1% failure rate of the accelerometer IC. When it dies, it takes the I2C bus with it causing problems for all the other devices (display, GNSS receiver, fuel gauge, etc). The solution is to remove the accelerometer from the product which is easy enough if you have a hot-air rework station and a pair of tweezers.
Good evening . My RTK express kit (purchased in dec 23) has exactly the same symptoms. Can i really simply try to remove the accelerometer from the board ? Is that accelerometer not required for proper FW execution ? As i live in france returning the product to you guys is probably a lot more challenging for me than attempting the repair here. I have all the required equipment.
Many thanks for your help.
Yes, removing the accelerometer is a likely fix. The firmware ~v3.0 and above automatically recognize and correctly handle the absence of the accel.