# Ubuntu: avrdude: ser\_open():: can't open device "-b57600"

**URL:** <https://community.keyboard.io/t/ubuntu-avrdude-ser-open-cant-open-device-b57600/1118>\
**Category:** Help and Getting Started\
**Created:** [February 24, 2018, 4:21pm UTC](https://community.keyboard.io/t/ubuntu-avrdude-ser-open-cant-open-device-b57600/1118 "2018-02-24T16:21:12Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![mr.fluffy](https://avatars.discourse-cdn.com/v4/letter/m/e36b37/32.png) [@mr.fluffy](https://community.keyboard.io/u/mr.fluffy)\
**Post date:** [February 24, 2018, 4:21pm UTC](https://community.keyboard.io/t/ubuntu-avrdude-ser-open-cant-open-device-b57600/1118/1 "2018-02-24T16:21:12Z")

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I can’t get arduino to flash on Ubuntu.  
I have installed 1.8.5 into /usr/local, and downloaded all the firmware, etc.  
Running ‘make flash’ fails with

`avrdude: ser_open(): can't open device "-b57600": No such file or directory`

the keyboard is apparently available on ttyACM0:

```
  [1328.524791] usb 4-1: Manufacturer: Keyboardio
  [1328.524793] usb 4-1: SerialNumber: Ckbio01E
  [1328.526948] cdc_acm 4-1:1.0: This device cannot do calls on its own. It is not a modem.
  [1328.526999] cdc_acm 4-1:1.0: ttyACM0: USB ACM device
```

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**Author:** ![rumpel](https://yyz1.discourse-cdn.com/flex031/user_avatar/community.keyboard.io/rumpel/32/626_2.png) [@rumpel](https://community.keyboard.io/u/rumpel)\
**Post date:** [February 24, 2018, 7:48pm UTC](https://community.keyboard.io/t/ubuntu-avrdude-ser-open-cant-open-device-b57600/1118/2 "2018-02-24T19:48:53Z")

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It’s a modem problem on Ubuntu. See here: [Flashing problem on Ubuntu (SOLVED)](https://community.keyboard.io/t/flashing-problem-on-ubuntu-solved/628/2)

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**Author:** ![mr.fluffy](https://avatars.discourse-cdn.com/v4/letter/m/e36b37/32.png) [@mr.fluffy](https://community.keyboard.io/u/mr.fluffy)\
**Post date:** [February 25, 2018, 9:26am UTC](https://community.keyboard.io/t/ubuntu-avrdude-ser-open-cant-open-device-b57600/1118/3 "2018-02-25T09:26:39Z")

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Thank you. For the record, my problem was embarassingly simple - I wasn’t holding down the ‘Prog’ key…

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**Author:** ![merlin](https://yyz1.discourse-cdn.com/flex031/user_avatar/community.keyboard.io/merlin/32/3416_2.png) [@merlin](https://community.keyboard.io/u/merlin)\
**Post date:** [February 25, 2018, 2:01pm UTC](https://community.keyboard.io/t/ubuntu-avrdude-ser-open-cant-open-device-b57600/1118/4 "2018-02-25T14:01:28Z")

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Looking at that error message again, it’s clear that `$DEVICE_PORT_BOOTLOADER` didn’t get set, and that argument to `avrdude` was unquoted, so you got a cryptic error message. We can definitely improve the error reporting here.