Repository navigation
MotionCal not recognizing data from micro:bit v2.20 #20
Description
Hello,
I'm trying to use MotionCal with my micro:bit v2.20 to calibrate the built-in magnetometer. I know MotionCal is primarily designed for Teensy boards, but I was wondering if it could work with other hardware as long as the data stream follows the same format.
Here's my setup:
- Micro:bit v2.20
- MicroPython (via Mu editor)
- Serial communication via UART at 115200 baud
- MotionCal detects my micro:bit as a COM port on windows 11
- Data stream verified with Putty
Raw:0,0,0,0,0,0,-18,33,-217
Raw:0,0,0,0,0,0,58,-55,-148
Raw:0,0,0,0,0,0,102,-195,-9
Raw:0,0,0,0,0,0,138,-268,177
Raw:0,0,0,0,0,0,87,-301,279
Delay in the code adjusted to 100 ms
This is the code running on the micro:bit:
from microbit import *
import time
uart.init(baudrate=115200)
while True:
magnet_strength_x = compass.get_x()
magnet_strength_y = compass.get_y()
magnet_strength_z = compass.get_z()
#new_byte = (uart.read(1))
#if new_byte == None:
# continue
raw = "Raw:0,0,0,0,0,0," + str(int(magnet_strength_x/100))+","+ str(int(magnet_strength_y/100))+","+ str(int(magnet_strength_z/100))+"\n"
uart.write(raw.encode('utf-8'))
#uni = "Uni:0,0,0,0,0,0," + str(magnet_strength_x/1000)+","+ str(magnet_strength_y/1000)+","+ str(magnet_strength_z/1000)+"\n"
#uart.write(uni.encode('utf-8'))
time.sleep_ms(100)However, MotionCal shows no response. Has anyone successfully used MotionCal with a micro:bit?
Are there any specific formatting requirements for the serial data stream that MotionCal expects?
Thanks in advance!
Activity
IanBUK commentedon Apr 24, 2025
I'm not in front of my computer right now, but I had similar issues and it turned out to be my baud rate and line endings.
GillisICWE commentedon Apr 25, 2025
It was indeed the control end.
For reference the following code works.
IanBUK commentedon Apr 25, 2025
I've got a fork where I'm adding a few things and will be making the baud rate etc. configurable.
tosa-no-onchan commentedon May 5, 2025
Hi.
My case is.
Raw:0,0,0,0,0,0,-241,26,447
Raw:0,0,0,0,0,0,-246,28,442
Raw:0,0,0,0,0,0,-245,24,443
Raw:0,0,0,0,0,0,-245,24,443
....
"Raw:0,0,0,0,0,0,mx,my,mz"
mx , my , mz : ICM-20948 Mageto Raw data
Arduino C code is.
Out put Rate : 10[hz]
Serial Speed: 115200
SOC and IMU device.
ESP32 and ICM-20948
ESP32 Arduino SparkFun ICM-20948 Library.
Data code is not encode to utf-8. Perhaps Arduino base code.
PC: Ubuntu 24.04
Build MotionCal from source code.
When MotionCal start calibrate mageto data,
I rotate the IMU-Device any direction on the same position.
MotionCal does work.
IanBUK commentedon May 29, 2025
My fork, at https://github.com/IanBUK/MotionCal, allows you to set the baud rate at runtime, and line endings. I've enabled it to work with a ' ' in the ascii package - my esp32 code was sending "Raw: " not "Raw:" and it took me longer than it should to understand why MotionCal wasn't using the package. #FacePalm
I've still got a 'noticeable' amount of work to do on it, to add something that's going to help my project, and I don't have access to a Windows or Linux machine to test on those platforms, but feel free to clone my fork and see if it does the good stuff for you.