[Physical product verified] Minimum JLink_STM32F103CBT6_Series 1

This hardware design is completely open source and can be used for personal use and not for commercial use . Please respect the spirit of open source hardware!

The software part comes from the Internet . If there is any infringement, please contact me to delete the software attachments.

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There are 4 issues in this series, and this issue is the 1st:

I have been learning STM32F10X, and the tool I have always used is STLink V2.0 for SWD downloading. Suddenly one day, a certain group of friends suddenly said that they would give me a homemade Jlink for use~

It is indeed very small ~ but it is actually a MiniUSB interface. In the 21st century, this interface is a bit OUT, so I might as well make it again by myself :)

Just do it as you say, dismantle the chip and accessories, search for the circuits of the PCB board, search for existing schematics on the Internet, and make more than a dozen JLINK OBs in one go~

The pictures below are the last few pieces left, and the rest of the test versions will be destroyed~

This is the smallest of these Jlinks. Of course, it was only the V1.0 version that came out initially.

The V1.0 version had many problems. There were many lines that did not need to be short-circuited in certain parts. Then I deleted them in the V2.0 version. I streamlined what needed to be streamlined, changed and remade, and then the V2.0 version came out. .

At present, I am using version V2.0, which can be used very well. But some friends said that the right-angle frame of the PCB is not good, so the V2.1 version with rounded corners has been released :)

This JLINK OB is the minimum peripheral version, with only 12 components among the mess of peripheral components ! The standard model used for the main control is STM32F103CBT6 , but after my actual testing, it is also possible to use STM32F101CBT6 or STM32F102CBT6 . In addition, if CBT6 is difficult to find, you can also use C8T6. Some C8T6 can be used as CBT6 .

The picture below is the actual welding diagram. You can weld according to the diagram. The crystal oscillator is Murata Ceramics 3213 8M capacitor. Because of its small size and built-in capacitor, I particularly like it!

JP2 is the output 3.3V short-contact point. Because the output part of this board is not fool-proof, it is easy to cause the target board to burn the MCU due to mis-insertion. So if Jlink does not carry 3.3V, this problem can be avoided to a large extent. If you don't want the output to have 3.3V, you don't need to short this.

JP1 is an LED switch. This hardware can burn two types of firmware currently circulating on the Internet. One is the old version of the firmware. The disadvantage is that when you click on Keil's JLINK configuration interface, a warning window will often pop up. When downloading SWD, there is no pop-up window. The speed is Not bad, there is 4M, this version of the firmware, JP1 short-circuit the left and middle; the other is a new version of the firmware, the disadvantage is that the LED light does not light up at ordinary times, it will light up only when SWD is downloaded, but no warning window will pop up. The speed is low, 2.25M, and this firmware shorts the middle and right sides. Both firmwares can be used on this board.

The one above TYPEC is the JLINK programming port, and RST is only used when the chip is write-protected. The method is based on Baidu, so I won’t explain it in detail.

Finally, I will upload my own finished picture. If you don’t understand, please click and leave a message.

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I don’t know why this picture is stretched so ugly, but the actual board is very beautiful.