11 ms·

STM32 Blue Pill as an Hid USB Keyboard

45 points by thealienthing 3y ago

gaudat 3y ago
The F103 microcontroller on the blue pill is the epicenter of price hiking during the semiconductor shortage. I've seen prices upwards of 35 USD for each chip. It was more expensive to get one of these chip than to get a Raspberry Pi. I think it is better to use the Nucleo series of evaluation boards from ST now as they have first party support from ST.
- topspin 3y ago
  I ordered a NUCLEO-G474RE directly from ST yesterday. I could only add one to the cart, whereas I wanted two. When I recently bought two NUCLEO-F334R8 I didn't encounter this. So apparently there is limited stock, and someone else that wants one can get it despite me. That's fine; I'll go back later and get another. It's great to see at least one damn company thinking this way. BTW, they're providing free shipping for a limited time!
  - kevin_thibedeau 3y ago
    You can purchase some of their boards via Mouser directly who is the one fulfilling orders on STs behalf.
- NikkiA 3y ago
  Jeez, I paid 1/3 of that for my black pills, and they're objectively better in every metric.
  - monocasa 3y ago
    Those jumped up in price about the same time. Hell, I saw fly by night operations buying up black pill boards just to pull the SoCs off to sell as sketch second sourced chips.
- mike_hock 3y ago
  Don't the Pis still go for 100 a pop or has that finally normalized now?
  - deepspace 3y ago
    I just bought a 4G 4B for $75 Canadian. More expensive than before the pandemic, but not outrageous. Of course, once you add a case, PSU, cables, etc, you are over $100 again.
  - squarefoot 3y ago
    Prices started to fall during the last months, but they're still far from the pre-shortage years. It will be a slow process, and being the Pi produced by a single manufacturer, they could take more time compared to other similar products.
- vbezhenar 3y ago
  I can buy pill for $3 and nucleo for $50. I guess it depends on location, but for me nucleo is like a luxury item.
pimlottc 3y ago
Can someone explain what this is actual for? Is this just a tutorial for creating your own DIY USB client device?
- tyingq 3y ago
  One example might be bridging an old dumb keyboard into working as a usb keyboard.
  - chem83 3y ago
    Could it also be used to bridge a BT keyboard to USB for the semi-rare cases where having a wired keyboard is necessary (BIOS access, boot loader, login screen etc.)? I expected this type of product to exist, but couldn't really find a good one after a cursory look.
    - duskwuff 3y ago
      In principle, yes, but you'd need something additional to act as a Bluetooth host. You'd probably be better off using a part that can do both, like an ESP32.
    - fanf2 3y ago
      I don’t know of an off-the-shelf way to implement what you want. There’s a usb-usb converter in QMK which allows you to add QMK features to any keyboard, but QMK does not have Bluetooth support. ZMK is designed for Bluetooth but doesn’t seem to have anything like QMK’s protocol converters (tho I might have looked in the wrong place). You might be able to DIY it with a Raspberry Pi Pico W, by gluing together the picow_bt_example_hid_host_demo and tinyusb_dev_hid_multiple_interface examples from https://github.com/raspberrypi/pico-examples https://github.com/raspberrypi/pico-examples
  - TechBro8615 3y ago
    Could this be used as a rubber ducky type device? I remember last I researched making a DIY rubber ducky it was quite difficult for some reason.
- 3y ago
extraduder_ire 3y ago
Do these boards still have that design flaw that prevents them from working right with USB? Especially for programming. I remember replacing a resistor on one four-ish years ago, so that I could use it in a usb2 port. (worked fine with a usb 1.1. hub)
leshow 3y ago
I've got one of these from way back and was meaning to do something similar in Rust. Yet another project that I just never got around to.
askiiart 3y ago
On that note,, does anyone have some resources on using a phone as a USB keyboard? It would be pretty useful not to have to haul around my bulky keyboard when I'm, say, just working on my server. Requiring root is fine.
- tejado 3y ago
  Android phones: https://github.com/tejado/android-usb-gadget https://github.com/tejado/android-usb-gadget I have unfortunately not yet developed any mouse/keyboard app for this. I only use it for https://github.com/tejado/Authorizer https://github.com/tejado/Authorizer
  - askiiart 3y ago
    Thanks so much for that, I ended up making my own app using Android USB Gadget and some code I stole from Authorizer. https://github.com/askiiart/android-usb-keyboard https://github.com/askiiart/android-usb-keyboard It's my first app, and it definitely shows, but it works. Though, it's definitely missing a fair number of keys.

45 points by thealienthing 3y ago

The F103 microcontroller on the blue pill is the epicenter of price hiking during the semiconductor shortage. I've seen prices upwards of 35 USD for each chip. It was more expensive to get one of these chip than to get a Raspberry Pi. I think it is better to use the Nucleo series of evaluation boards from ST now as they have first party support from ST.

topspin 3y ago
I ordered a NUCLEO-G474RE directly from ST yesterday. I could only add one to the cart, whereas I wanted two. When I recently bought two NUCLEO-F334R8 I didn't encounter this. So apparently there is limited stock, and someone else that wants one can get it despite me. That's fine; I'll go back later and get another. It's great to see at least one damn company thinking this way. BTW, they're providing free shipping for a limited time!
- kevin_thibedeau 3y ago
  You can purchase some of their boards via Mouser directly who is the one fulfilling orders on STs behalf.
NikkiA 3y ago
Jeez, I paid 1/3 of that for my black pills, and they're objectively better in every metric.
- monocasa 3y ago
  Those jumped up in price about the same time. Hell, I saw fly by night operations buying up black pill boards just to pull the SoCs off to sell as sketch second sourced chips.
mike_hock 3y ago
Don't the Pis still go for 100 a pop or has that finally normalized now?
- deepspace 3y ago
  I just bought a 4G 4B for $75 Canadian. More expensive than before the pandemic, but not outrageous. Of course, once you add a case, PSU, cables, etc, you are over $100 again.
- squarefoot 3y ago
  Prices started to fall during the last months, but they're still far from the pre-shortage years. It will be a slow process, and being the Pi produced by a single manufacturer, they could take more time compared to other similar products.
vbezhenar 3y ago
I can buy pill for $3 and nucleo for $50. I guess it depends on location, but for me nucleo is like a luxury item.

pimlottc 3y ago

Can someone explain what this is actual for? Is this just a tutorial for creating your own DIY USB client device?

tyingq 3y ago
One example might be bridging an old dumb keyboard into working as a usb keyboard.
- chem83 3y ago
  Could it also be used to bridge a BT keyboard to USB for the semi-rare cases where having a wired keyboard is necessary (BIOS access, boot loader, login screen etc.)? I expected this type of product to exist, but couldn't really find a good one after a cursory look.
  - duskwuff 3y ago
    In principle, yes, but you'd need something additional to act as a Bluetooth host. You'd probably be better off using a part that can do both, like an ESP32.
  - fanf2 3y ago
    I don’t know of an off-the-shelf way to implement what you want. There’s a usb-usb converter in QMK which allows you to add QMK features to any keyboard, but QMK does not have Bluetooth support. ZMK is designed for Bluetooth but doesn’t seem to have anything like QMK’s protocol converters (tho I might have looked in the wrong place). You might be able to DIY it with a Raspberry Pi Pico W, by gluing together the picow_bt_example_hid_host_demo and tinyusb_dev_hid_multiple_interface examples from https://github.com/raspberrypi/pico-examples https://github.com/raspberrypi/pico-examples
- TechBro8615 3y ago
  Could this be used as a rubber ducky type device? I remember last I researched making a DIY rubber ducky it was quite difficult for some reason.
3y ago

extraduder_ire 3y ago

Do these boards still have that design flaw that prevents them from working right with USB? Especially for programming. I remember replacing a resistor on one four-ish years ago, so that I could use it in a usb2 port. (worked fine with a usb 1.1. hub)

leshow 3y ago

I've got one of these from way back and was meaning to do something similar in Rust. Yet another project that I just never got around to.

askiiart 3y ago

On that note,, does anyone have some resources on using a phone as a USB keyboard? It would be pretty useful not to have to haul around my bulky keyboard when I'm, say, just working on my server. Requiring root is fine.

tejado 3y ago
Android phones: https://github.com/tejado/android-usb-gadget https://github.com/tejado/android-usb-gadget I have unfortunately not yet developed any mouse/keyboard app for this. I only use it for https://github.com/tejado/Authorizer https://github.com/tejado/Authorizer
- askiiart 3y ago
  Thanks so much for that, I ended up making my own app using Android USB Gadget and some code I stole from Authorizer. https://github.com/askiiart/android-usb-keyboard https://github.com/askiiart/android-usb-keyboard It's my first app, and it definitely shows, but it works. Though, it's definitely missing a fair number of keys.