# Teensy connection issue

**URL:** <https://mworks.discourse.group/t/teensy-connection-issue/1095>\
**Category:** Support\
**Created:** [May 16, 2025, 6:44pm UTC](https://mworks.discourse.group/t/teensy-connection-issue/1095 "2025-05-16T18:44:55Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![vonaviv](https://avatars.discourse-cdn.com/v4/letter/v/b19c9b/32.png) [@vonaviv](https://mworks.discourse.group/u/vonaviv)\
**Post date:** [May 16, 2025, 6:44pm UTC](https://mworks.discourse.group/t/teensy-connection-issue/1095/1 "2025-05-16T18:44:56Z")

</div>

Hi Chris,

I having a problem with connecting a Teensy 4.1 in MWorks 12.2. I hope you can help me out.  
Here is the code I am running:

```auto
var teensy_connection = 0

firmata teensy (
    serial_port = '/dev/cu.usbmodem161512901'
    data_interval = 5ms
    reconnect_interval = 500ms
    connected = teensy_connection
    alt=teensy
) {
}

protocol {
    start_io_device (teensy)
    wait (1s)
    if (teensy_connection == 1) {
        report('Teensy connected')
    }
    stop_io_device(teensy)
}

```

and here are the logs:

```auto
27:54:55: Configuring Firmata device "teensy"...
27:54:58: WARNING: Received unexpected command (0x30) from Firmata device "teensy"
27:54:59: WARNING: Received unexpected command (0x30) from Firmata device "teensy"
27:55:00: ERROR: Firmata device "teensy" did not respond to request for protocol version
27:55:00: Experiment successfully loaded, using protocol: idp105553180631423
27:55:04: Opened data file: /Users/vladyslav/Documents/MWorks/Data/vladyslav-teensy-20250516-204357.mwk2
27:55:04: Setting protocol to idp105553180631423
27:55:04: Running MWorks 0.12.2 (2023.10.02)
27:55:04: Current date/time is Fri May 16 20:43:57 CEST 2025
27:55:04: Using protocol idp105553180631423
27:55:04: Called start on state system
27:55:04: Starting state system....
27:55:05: State system ending
27:55:05: Resetting experiment

```

Best,  
Vladyslav

---

<div class="post-metadata">

**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\
**Post date:** [May 19, 2025, 2:40pm UTC](https://mworks.discourse.group/t/teensy-connection-issue/1095/2 "2025-05-19T14:40:42Z")

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Hi Vladyslav,

Have you [installed the Firmata firmware](https://mworks.discourse.group/t/setting-up-an-arduino-or-compatible-microcontroller-as-a-firmata-device/57) on the Teensy?

Cheers,  
Chris

---

<div class="post-metadata">

**Author:** ![vonaviv](https://avatars.discourse-cdn.com/v4/letter/v/b19c9b/32.png) [@vonaviv](https://mworks.discourse.group/u/vonaviv)\
**Post date:** [May 27, 2025, 7:50am UTC](https://mworks.discourse.group/t/teensy-connection-issue/1095/3 "2025-05-27T07:50:33Z")

</div>

As it turns out I have to install the firmware 😅  
Thanks!

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<div class="post-metadata">

**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\
**Post date:** [May 27, 2025, 12:53pm UTC](https://mworks.discourse.group/t/teensy-connection-issue/1095/4 "2025-05-27T12:53:57Z")

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