Works, but on jp so sluggish as to work intermittently, will try on eos

exercises/25_motioncal_tbeam/README.md

@@ -0,0 +1,57 @@
+# Exercise 25: MotionCal T-Beam Bridge
+
+Streams the T-Beam Supreme QMC6310 magnetometer in the ASCII format accepted by
+Paul Stoffregen's MotionCal desktop tool.
+
+https://github.com/PaulStoffregen/MotionCal.git (fetch)
+
+MotionCal expects:
+
+```text
+Raw:accel_x,accel_y,accel_z,gyro_x,gyro_y,gyro_z,mag_x,mag_y,mag_z
+```
+
+This exercise only has a magnetometer, so it sends a stationary accelerometer
+placeholder and zero gyro:
+
+```text
+Raw:0,0,8192,0,0,0,mag_x,mag_y,mag_z
+```
+
+The magnetic values are converted from SensorLib Gauss readings into MotionCal's
+integer units where 1 count is 0.1 microtesla.
+
+## Build
+
+```sh
+cd /usr/local/src/microreticulum/microReticulumTbeam/exercises/25_motioncal_tbeam
+source /home/jlpoole/rnsenv/bin/activate
+pio run
+```
+
+## Upload
+
+```sh
+source /home/jlpoole/rnsenv/bin/activate
+pio run -t upload
+```
+
+Use a specific board environment if needed:
+
+```sh
+pio run -e guy -t upload
+```
+
+## MotionCal
+
+Build and run MotionCal as before:
+
+```sh
+cd /usr/local/src/MotionCal
+make WXCONFIG=wx-config LDFLAGS="-lglut -lGLU -lGL -lm"
+GDK_BACKEND=x11 ./MotionCal
+```
+
+Select the T-Beam USB serial port in MotionCal. The firmware also accepts
+MotionCal's 68-byte calibration packet and echoes `Cal1:` and `Cal2:` lines so
+MotionCal can confirm the send.