Hello Luffe,
This is definitely unusual behavior, and the same sequence of events from two different units makes the situation even more uncanny. Let’s see what we can do!
First, could you also post the logs from the second unit? This is to compare them with the ones you just sent (thank you for that) and see if we can spot any interesting lines.
I remember reading somewhere (and it has happened a couple of times on one of my Pis as well) that similar events are not unheard of. They could point to a potential startup timing issue, either in the power supply behavior or the way hardware peripherals initialize during the early boot phase.
This is because the Pi or Shake boards may not receive a stable voltage quickly enough during the first boot. While at the second boot, they work because some components (like capacitors or regulators) are still partially charged/stabilized. This is especially likely if using a shared or switched power source.
From the current logs, I see:
2025 154 07:30:56: Unable to read Firmware version number off of Serial Port /dev/serial0 after trying for 15 seconds, cannot continue!
2025 154 07:30:56: Is the Pi computer connected to the Raspberry Shake Board? Please confirm and try again.
and
2025 156 10:07:54>> No Data has been received from the MCU in 12 read attempts.It appears the MCU is not transmitting data. This is a fatal condition and should be investigated if this condition persists!
2025 156 10:07:54>> Data has been successfully received, fatal condition resolved.
2025 156 10:07:54>> internal error: buffer overflow! cannot process read data...
2025 156 10:07:54>> buf: AU”EÁDªUe,]І¢ÔUáEEщ‹BUVIÐU QSÁUÑTE
2025 156 10:07:54>> 4S‚RU»$AQl‘EÁU
which continue to point to a possible power supply issue. In any case, I think it’s worth going through the entire basic troubleshooting pipeline to remove any possible cause. Even if you have already checked some (or all) of these points.
Please check again if the current power supply you are using is continuing to deliver a stable voltage between 5.0 and 5.2V and a current of at least 2.5A at all times (3.0A if the Raspberry Pi board that is being used is a RPi4), as a decrease in power could lead to data services interruption.
If possible, connect the Shake to a single wall socket (or try different ones to see if there is a difference). And, if you have another Pi power supply that you know is in working condition, please try exchanging the current one with that and see if the Shake now starts correctly at first boot.
A second check that you can do is to see if all the connections between the sensor, the blue Shake board, and the Pi board are still solid and free from dirt or any other element that could compromise transmission. If you decide to disassemble the Shake during this process, please refer to our recommended ESD (ElectroStatic Discharge) guidelines and assembly/disassembly video guides here.
If all these checks come out as positive, then I would recommend re-burning the microSD card again (or using a different microSD card, which I advise for this case) after formatting and erasing all its data/partitions first (you can use DISKPART for this as it is very efficient), and see how the Shake behaves with the newly installed system, removing potential issues derived from corrupted files. I will leave the burning instructions link here for your convenience: microSD card topics.
Thank you for your collaboration.