---
title: "Comment by Andrey on \"STM32F4 Embedded Rust at the HAL: Timer Interrupts\" | Hashnode"
description: "Hello, thanks for the article! I'm trying to set a low value for timer it panics, e.g. timer.start(100.millis()).unwrap(); I'm using STM32F103C8T6. Any thoughts"
url: "https://hashnode.com/posts/stm32f4-embedded-rust-at-the-hal-timer-interrupts/630cc3b556df9e8e502523bf/comment/67a0a6c840988f0f9f286ed6"
---

[Discussion](https://hashnode.com/posts/stm32f4-embedded-rust-at-the-hal-timer-interrupts/630cc3b556df9e8e502523bf)

Comment [STM32F4 Embedded Rust at the HAL: Timer Interrupts](https://hashnode.com/posts/stm32f4-embedded-rust-at-the-hal-timer-interrupts/630cc3b556df9e8e502523bf)

[Andrey](https://hashnode.com/@hawaiian)

[Feb 3, 2025](https://hashnode.com/posts/stm32f4-embedded-rust-at-the-hal-timer-interrupts/630cc3b556df9e8e502523bf/comment/67a0a6c840988f0f9f286ed6)

Hello, thanks for the article! I'm trying to set a low value for timer it panics, e.g.

`timer.start(100.millis()).unwrap();`

I'm using STM32F103C8T6. Any thoughts on why?

[Omar Hiari](https://hashnode.com/@omarhiari)

[Feb 3, 2025](https://hashnode.com/posts/stm32f4-embedded-rust-at-the-hal-timer-interrupts/630cc3b556df9e8e502523bf/comment/67a0a6c840988f0f9f286ed6#reply-67a0a884e6c76c8e06618c2f)

Hello [Andrey](https://hashnode.com/@hawaiian), it's been a while since I worked with STM32s and Rust, though could you possibly share what the panic message says? It's possible that it would say that you are unwrapping an error variant.

Since the `start` method returns a `Result`, maybe you can use a `match` statement to print out the error as well. This could give some indication.

[Andrey](https://hashnode.com/@hawaiian)

[Feb 3, 2025](https://hashnode.com/posts/stm32f4-embedded-rust-at-the-hal-timer-interrupts/630cc3b556df9e8e502523bf/comment/67a0a6c840988f0f9f286ed6#reply-67a0e52f52e680d5e965c3f7)

I found out the issue, it's newbee one :) I enabled interrupts early and it ISR is called before I initialized a device, working with that device caused an error. Thanks for the response and the blog!