RoboMaster fluorescent charging module

PDF_RoboMaster Fluorescence Charging Module.zip

Altium_RoboMaster fluorescent charging module.zip

PADS_RoboMaster fluorescence charging module.zip

BOM_RoboMaster Fluorescence Charging Module.xlsx

97254

USB to 4-port serial TTL downloader with no cold start

USB to 4TTL downloader, cold start-free circuit

I. Product Introduction:
This USB-to-4-port serial programmer, built using CH344, has been tested and can download STC series microcontrollers, including the ESP32 microcontroller. For the ESP32 microcontroller, the factory mode of the official flash_download_tool allows simultaneous downloading to multiple devices.
II. Circuit Design
: The cold-start circuit uses a transistor and PMOS configuration. During programming, the RTS pin is pulled low, interrupting the 5V power supply for several hundred milliseconds. The circuit diagram uses 1uF pins (C1, C2, C3, C4), which is sufficient for programming STC microcontrollers. My actual prototype test circuit used 10uF, resulting in a longer 5V interruption time compared to 1uF.
III. Discussion
1. The programming interface can be modified according to your usage. If using 3.3V, add an AMS1117-3.3 to convert the power supply. CH344 supports 3.3V and 5V.
2. Programming ESP32 requires grounding GPIO00 to put the module in download mode. To ensure compatibility with STC microcontrollers, I did not directly implement the GPIO00 pin pull-down circuit on the programmer. You can modify it as needed.
3. The CH344's CFG pin, the manual says, can be set to enable or disable flow control. I have reserved the interface, but I don't know the specific usage. It seems there's no difference between CFG being grounded and floating. Discussion on the usage of CFG is welcome.

PDF_USB to 4-port Serial TTL Downloader - Cold Start-Free.zip

Altium_USB to 4-port Serial TTL Downloader - Cold Start-Free.zip

PADS_USB to 4-port Serial TTL Downloader - Cold Start-Free.zip

BOM_USB to 4-port Serial TTL Downloader - Cold Start-Free.xlsx

97257

Digital oscilloscope

Instrumentation Training Questions

       This project utilizes analog circuit components such as resistor dividers, operational amplifiers, and comparators to implement signal conditioning, amplification, shifting, filtering, and comparison functions to adapt to the input and output range of the STM32H750's ADC and DAC, thus realizing the oscilloscope's sampling and output functions. It also uses switches and voltage divider networks to implement the segmentation function of analog input and output channels, improving the measurement accuracy and output resolution of small signals. Furthermore, it utilizes the STM32H750's timer function to implement triggering and frequency measurement functions.
Project Functions: This project can function as a dual-channel oscilloscope, measuring analog signals within a ±15V range and converting them into digital signals within a 0-3.3V range for sampling by the STM32H750's ADC. It can also function as a single-channel signal source, outputting analog signals within a ±10V range, which are then generated by the STM32H750's DAC. It can also square-wave the input signal and utilize comparators and timers to implement triggering and frequency measurement functions.