Kinetis K64F demo board is excellent little board for experimenting with ethernet. There is no quick step-by-step tutorial for building simple web server on this board. The following instructions help bringing working HTTP server on FRDM K64F with one index page and second page with simple CGI script to print out some random numbers. This is absolute minimum for developing any web based gadget with this board.
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.
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.
This is simple, small interface between USB and alphanumeric LCD with 16×2 characters. It is using CDC class – Virtual COM port.
Microcontroller is from STM32 cortex M0 value line family: STM32F070F6. This small “gizmo” has very attractive price and good choice of peripheral devices, like ADC, USB, plenty of timers, etc… Really nice device in “DIY-friendly” package – TSSOP20.
I have some I2C sensors which are capable of running from low supply voltages. Host microcontroller has 3,3 or 5V supply, which is usually out of absolute maximum range, when I2C device is supplied with e.g. 1,8V. The sensor is usually very low power, which means simple emitter follower could do the low voltage supply.
The circuit schematic is shown in following drawing (click to enlarge):
