I bought few STLINKs V3 (MODS) modules. It is ST-Link module to be embedded on some target system. It can be used as any other ST-Link, but the pinout and castelated via contacts have 50 mils pitch. So I prepared very simple, single sided breakout board with 100 mils pitch. The most important signals are connected to larger pads:
SWD
VCP Rx/Tx
Bootloader Bridge via UART
Supply
The “toner transfer” pdf is here (with marked signals):
Amazfit pace went swimming and drowned 🙂 After unsuccessful warranty claim I put watch in the drawer and forget about it because it looks “unopenable”. Today I learned it could be opened easily when heated. So I decided to try it. I grabbed hot air gun and shot few blows into the housing heating up to 80°C. It is just below 85°C, which could be a limit for some electronic components.
The proper tool to open the smart watch
The disasembly was piece of cake. Just separate the two pieces.
Modern battery operated portable devices use smart battery packs. Every new development of an electronic medical device must follow strict design flow defined by world-wide or local regulatory
directives. The development process of any such device using smart battery pack requires specific operating conditions to meet the testing criteria. When smart battery pack is one of the main power sources the host system should be tested with several battery states. The testing is necessary during development, validation and later in production testing.
This LED decoration is for beginners in microcontroller applications. It has 8 LEDs, audio generator and possibility to interconnect with other modules. The PCB is simplified to certain level in order to be manufacturable on a single sided substrate with minimum effort. There are only two wire bridges and one 0 ohm resistor in addition to other components. The LED decoration can be used in school projects or for new-years fun. Of course it’s not limited to X-mas tree. It can be used during Bodhi Day, Hanukkah, Id al-Adha, Winter Solstice celebration, Saturnalia, Yule, Kwanza, Omisoka or any other occasion which might come at the end of the year, when day is short and some LED blinking device might rise your mood.
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:
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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.
I am using U-Link from Keil for my debugging purposes. Sometimes it is quite bulky. I decided to design STLink V2 on a single-sided PCB in smallest possible size. Here is how it looks:
This is preliminary preview. I will post more details after first testing.
Full bunch of wires is hanging from each HAM station and PC connected to the station: CAT, audio, each via dedicated interface for isolation or level shifting. Additional mess is with parrots or digital interfaces for digital mode. I wanted simple solution, which can be conected to PC via single USB cable.
I was looking for simple audio CODEC and found WM8731. To have enough processing power for some simple DSP audio I chose cortex M4F microcontroller. There is also micro-SD on the board for audio recording and playback, two mini-DIN connectors with YAESU pinout and galvanic isolation for USB. I stareted this project few months ago. I will add posts when I will make progress with module programming.
Many micro-controller circuits are powered from the USB port. Supply voltage is usually less than USB five volts. Supply circuit has adjustable output voltage with few jumpers. Some circuits require two supply voltages, one for digital part and second for analog part. Jumpers and resistors are selected such that when no jumper is inserted, the output voltage will be at minimum level. This prevents electronic circuit from damage when jumpers are forgotten. It’s shown in schematic:
