I've been trying to get this to compile/install using the Arduino IDE and i'm not getting anywhere... Once installed, the M5Paper just continuously reboots, flashing the screen on and off.

Watching the serial monitor I see this repeated on each reboot... Any suggestions?

Rebooting...
M5EPD initializing...OK
Guru Meditation Error: Core 1 panic'ed (LoadProhibited). Exception was unhandled.
Core 1 register dump:
PC : 0x400d7c9f PS : 0x00060330 A0 : 0x800d48ea A1 : 0x3ffb1f10
A2 : 0x3ffc19a0 A3 : 0x00000000 A4 : 0xffffffff A5 : 0x3ffc1a78
A6 : 0x0001fa40 A7 : 0x00000000 A8 : 0x00000000 A9 : 0x3ffb1ee0
A10 : 0x00000000 A11 : 0x00000000 A12 : 0x00000000 A13 : 0x000003c0
A14 : 0x0000021c A15 : 0x3f407a74 SAR : 0x00000011 EXCCAUSE: 0x0000001c
EXCVADDR: 0x00000000 LBEG : 0x400014fd LEND : 0x4000150d LCOUNT : 0xffffffff

Backtrace: 0x400d7c9f:0x3ffb1f10 0x400d48e7:0x3ffb1f40 0x400d5d7e:0x3ffb1f90 0x400e174b:0x3ffb1fb0 0x40088dbd:0x3ffb1fd0

@sodoku Thanks. I just got an email that the M5's are back in stock... Digikey still showing backordered though. Guess i'll have to order from M5 directly.

Oh, awesome, thanks very much. Is that document linked on the M5 site somewhere?

Is there any estimate for when the next batch of M5Papers will be available? I missed the first round but have been waiting patiently for another. Bonus points if anyone knows when Digikey will have them in North America.

@m5stack It would be good if there was some documentation explaining how to use the M5Stack to do the transparent transmission. Could that be added to the GPS Module product page, or linked from it? Right now there's a link to the software but no indication how one would use it with the GPS module.

@m5stack can you be more specific? What software are you referring to? The Windows software linked to on the GPS module page (https://www.u-blox.com/en/product/u-center-windows)? Can that software talk to the GPS to update it through the USB connection to the M5Stack while it's connected?

Has anyone done any work with the M5Stack mounted in a vehicle?

I've got the IMU displaying pitch and roll graphically, and it works very nicely on a desktop. But when mounted in a vehicle, the engine vibration starts it bouncing around and the stability is lost. Roll and pitch errors +/-10-15 degrees bouncing back and forth make the display unreadable.

Has anyone else had this experience, and is there a way to filter the data to smooth out the readings?

Worth noting just in case others don't notice this:

1. The internal antenna is connected by default.
2. To use the external antenna, you'll have to unplug the internal and plug in the external antenna cable.
3. Getting an initial fix from the internal antenna will take alot longer than plugging in the external antenna.
4. Once you've got a fix with the external antenna, the internal antenna will pick up quicker the next time you try it.
5. As long as you power up the GPS once in a while and let it get an updated fix, the internal antenna should keep connecting reliably. The external antenna wlll be faster, but the internal should be good enough.

Thanks for the Twitter link, i've reached out to see if he can help.

I did figure out how to do a rudimentary calibration by waiting for a button press and then setting the current values for roll and pitch to "offset" values and "correcting" subsequent readings using them. It works well enough for now, and I can calibrate in different orientations.

The only issue now is that this just uses the magnetometer, I think... I'm only reading &roll and &pitch from IMU.getAhrsData(), i'm not reading the gyro values. So this is susceptible to motion, if I slide the unit from side to side on the table the horizon tilts when it should stay horizontal.

I've been working on an artificial horizon display on the M5 Stack Fire. This is based on the "bodmer" code, but modified for the higher-resolution screen of the M5 Stack. Here's a video taken just after I got the code working:

https://photos.app.goo.gl/uT6EryccucaQbaix6

Since then, I've replaced the random pitch and roll angle generator with calls to IMU.getAhrsData();. This works, except for two issues:

1. The "zero" is not level. With the Fire sitting flat on the table (screen parallel to table surface), pitch reads zero but roll reads 10 degrees off.

2. I really want this to sit with the screen perpendicular to the table... ie. pitch=90.

I can manually go in the code and set the offsets, but is there a way to "zero" the IMU before it starts? The IMU demo sketch offers initAK8963() and initMPU9250() but neither apply to the Fire, which now ships with an MPU6886 according to the M5 support email.

Help appreciated?