# Need help! Unable to read tmc uart 'my\_stepper' register GSTAT

**URL:** <https://klipper.discourse.group/t/need-help-unable-to-read-tmc-uart-my-stepper-register-gstat/15415>\
**Category:** General Discussion\
**Created:** [April 1, 2024, 9:11pm UTC](https://klipper.discourse.group/t/need-help-unable-to-read-tmc-uart-my-stepper-register-gstat/15415 "2024-04-01T21:11:46Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![audris](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@audris](https://klipper.discourse.group/u/audris)\
**Post date:** [April 1, 2024, 9:11pm UTC](https://klipper.discourse.group/t/need-help-unable-to-read-tmc-uart-my-stepper-register-gstat/15415/1 "2024-04-01T21:11:46Z")

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### Basic Information:

Printer Model:  
 MCU / Printerboard: skr pico + raspberry pico  
 Host / SBC mainsail  
 klippy.log

Hello! I wanted to add exstra stepper motor for my printer with external BTT tmc2209 1.3v with raspberry pico. but I have issue I can run motor for one time and then I have this error “Unable to read tmc uart ‘my\_stepper’ register GSTAT”

 ![Screenshot from 2024-04-02 00-01-42](https://global.discourse-cdn.com/free1/uploads/klipper/original/2X/8/8de22552635b743e0123d1ceb305a20e098f8e31.png)

wiring

 ![Screenshot from 2024-04-01 23-58-27](https://global.discourse-cdn.com/free1/uploads/klipper/original/2X/a/add503ba7ef6a1ec22a7bcfb2d84ac32a171910d.jpeg)

printer.cfg

```auto
[manual_stepper my_stepper]
step_pin: pico:gpio2
dir_pin: !pico:gpio3
enable_pin: !pico:gpio5
microsteps:8
rotation_distance:10
# See the "stepper" section for a description of these parameters.
#velocity:
# Set the default velocity (in mm/s) for the stepper. This value
# will be used if a MANUAL_STEPPER command does not specify a SPEED
# parameter. The default is 5mm/s.
#accel:
# Set the default acceleration (in mm/s^2) for the stepper. An
# acceleration of zero will result in no acceleration. This value
# will be used if a MANUAL_STEPPER command does not specify an ACCEL
# parameter. The default is zero.
#endstop_pin:
# endstop_pin: tmc2209_my_stepper:virtual_endstop

# Endstop switch detection pin. If specified, then one may perform
# "homing moves" by adding a STOP_ON_ENDSTOP parameter to
# MANUAL_STEPPER movement commands.

[tmc2209 manual_stepper my_stepper]
uart_pin:pico:gpio1
tx_pin:pico:gpio0
#select_pins:
#interpolate: True
run_current:0.8
hold_current:0.8
#sense_resistor: 0.110
stealthchop_threshold: 0
# See the "tmc2208" section for the definition of these parameters.
uart_address: 0

```

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<div class="post-metadata">

**Author:** ![EddyMI3D](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/eddymi3d/32/1981_2.png) [@EddyMI3D](https://klipper.discourse.group/u/EddyMI3D)\
**Post date:** [April 2, 2024, 6:29am UTC](https://klipper.discourse.group/t/need-help-unable-to-read-tmc-uart-my-stepper-register-gstat/15415/2 "2024-04-02T06:29:13Z")

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The TMC2209 can run on a one wire UART connection with Klipper. So the TX wire is not needed.

You may have missed the Vdd power:

 ![grafik](https://global.discourse-cdn.com/free1/uploads/klipper/original/2X/d/d371713f99aedc8f76ac19b01ee08666615184f8.jpeg)

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<div class="post-metadata">

**Author:** ![audris](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@audris](https://klipper.discourse.group/u/audris)\
**Post date:** [April 2, 2024, 12:42pm UTC](https://klipper.discourse.group/t/need-help-unable-to-read-tmc-uart-my-stepper-register-gstat/15415/3 "2024-04-02T12:42:04Z")

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Thanks for solving my problem, it was a silly problem, I didn’t connect the vdd to 3.3v, but I still don’t understand why the stepper motor could spin one move when I run command “MANUAL\_STEPPER STEPPER=my\_stepper MOVE=10 SPEED=5”

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<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/klipper/original/1X/64419bf2aac6639e6ef5cef200dcd456b0a01ac3.png) [@system](https://klipper.discourse.group/u/system)\
**Post date:** [May 2, 2024, 10:43pm UTC](https://klipper.discourse.group/t/need-help-unable-to-read-tmc-uart-my-stepper-register-gstat/15415/4 "2024-05-02T22:43:04Z")

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