This keyboard is more than 10 years old. I got it for free but it had its problems. First one was a PS/2 interface. Not ideal for a keyboard used in 2016. Second problem was software for programming this keyboard. It came on not one, but two diskettes with DOS and Windows versions of the software.
That’s where I decided to take it apart and replace electronics inside. New controller is based on KeyWarrior IC which is capable of scanning 16×8 matrix.
This keyboard merges a standard keyboard with a jog controller for a CNC machine. Upper half are “normal” keys and bottom half is for controlling my CNC machine. The shortcut keys will save me a lot of time and trouble when working with the machine.
Communication between microcontrollers is always interesting topic. I was looking for simple, efficient and reliable protocol between several microcontrollers. First I have to choose the physical layer. One of the most commonly used multipoint buses is RS485. Due to simplicity I choose half-duplex RS485. Only two wires is all it needs to establish link between two devices:
Keep in mind that my device does NOT comply with any safety standards whatsoever and safety is based only on common sense. It should not be used for anything else but model rocket hobby.
I started of with a simple schematics as shown below. The idea was simple – to heat a thin wire with huge electrical current as quickly as possible. I used N-channel MOSFET with drain current rated at 80 A. Power source is 4S 5Ah LiPo battery rated at 20C which means that it’s capable of delivering 100A constantly.
The R.Pi is excellent module for many applications. Unfortunately it is not easy to stack USB modules connected to it. When USB module, e.g. RTL-SDR is attached to the R.Pi, the whole package become very long requiring larger box. One solution is to use USB extension cable, but it again require additional space. Here is another, more compact solution:
remove the USB connector from your module
place SIL header at the pins for USB connector
connect the USB module back “folded around the corner”
Category: R.Pi, Tips and Tricks |
Comments Off on Raspberry Pi “folded” USB connector
I took old cover from plastic sewer pipe (it was never used ha ha). Then I drilled four holes for M3 screws and one bigger hole for camera module lens. The housing was prepared from one litre PET bottle. I cut the bottle to proper size and inserted raspberry Pi with the camera inside the bottle. Next the LAN cable with passive 5V “PoE” was inserted.
Finally, I heated the bottle with hot air gun at the camera side to shrink a little bit and tightly close the gap between the plastic camera “holder” and the bottle .
Today I found out how to “flash” blank STM32F103xC to make STLINK V2 debugger interface.
So, instead of desoldering from Discovery board to make miniture STLINK debug interface:
it’s possible to solder blank (or any) STM32F10x with USB and at least 64k flash + 20k RAM, program it with STLINK V2 Firmware and use your new USB dongle for debugging STM32 or STM8 devices.
