Mini portable mini oscilloscope DSO+i2c tool +UART serial tool + shell

20240606

Fixed the issue where the I2C bus was pulled dead when the I2C Tool occasionally read the registers.

20240226

Open-source shell.

20231122

I2C fixed the problem that the ACK would be slow in some cases, resulting in the inability to recognize the ACK, and added the I2C clock extension function.

Feature introduction

1. Based on the modification of Lao Liu's oscilloscope, all the oscilloscope functions of the previous Lao Liu version are retained. The hardware has been mini as much as possible, has been revised many times, the current size of 28x48mm, in order to reduce the height, the physical use of the SMD EC11 encoder, SMD and plug-in EC11 can be used, welding to adjust the position.

2. The chip is used STC8A8K64D4, and the price of the chip in the STC8A8K64S4A12 is too much, and the function and STC8A8K64D4 are basically the same.

3. Add CH340N chip, you can directly use usb to realize program download and serial port reading and writing.

4. Add IP5306 charge and discharge management chip, which can be connected to lithium battery to achieve mobile portability. In oscilloscope mode, the battery does not have a 35s auto-shutdown function, and a pulse will be sent through the P36 interface to make it not automatically shut down. In lithium battery mode, press the P36 button once to power on with lithium battery power, and double click to turn off lithium battery power supply.

5. Add i2c tool function, support read and write i2c device, can dump, and support delay at the same time.

• The write format is written to the 0x0c device, and the register 0x0a write 0x01, with a delay of 100ms;
• The read format is to read the value of the 0x0B register 0x0c the device; If the delay is 1000 ms, the format is;
• Scan the I2C device format;
• Dump i2c device format, 0c is the address of the device to be dumped.
• The default baud rate of i2c is 115200, which is accessed through the serial port tool.
• Enter to get help.

6. Power on the default to enter the i2c tool function, and automatically scan the i2c device once, if you need to scan again, you can press the P36 key or rotate the EC11 encoder. Press the P36 button once, IP5306 is equivalent to being activated once, start the timer from pressing P36, and automatically power off after 35s.

7. Press and hold the P36 button, press the RST button again, automatically enter the oscilloscope mode, the oscilloscope mode uses the battery function without 35s automatic shutdown limit, when long press ec11 and then exit, automatically activate the 35s automatic shutdown function.

Hardware precautions

1. If you only want to experience the oscilloscope function, and there is no need for other functions, you can not solder the corresponding components IP5306, CH340N, AMS1117, Q1, Q2 and the corresponding peripheral devices, there are corresponding soldering short-circuit points in the PCB, and the two power supply short-circuits +5V can be used for power supply.

2.The PIN1 and PIN2 of J6 need to be shorted together to power the mcu, the purpose of this pin is that the mcu needs to be completely powered off when it is downloaded for the first time, otherwise the download will fail.

3.The PIN5 and PIN7 of J6 are shorted together, so that they can communicate through the USB->ch340N->stc monolithic serial port. To remove this shorting, you can use PIN7 and PIN9 as TTL tools.

4. If you use the i2c tool function, J6 PIN3, PIN4, PIN6 are the i2c level selection pins, support 3v3 and 1v8 levels.

5. There is a PWR power button of ip5306 in the physical display, and it has been merged with P36 in the updated version, so that it will be more convenient to use.

Download Notes

1. When downloading for the first time, try to use an external serial port tool to download, STC single-chip microcomputer download requires the serial port to be connected first, and then the single-chip microcomputer is in the power supply, be sure to remember this order.

2. The download settings are as follows, and the IRC frequency is selected as 27MHz.

3. Uncheck the reset pin as the I/O port, so that the RST button can be used as the reset button, and press this button to achieve automatic download when downloading next time.

4. Check the box to add important test parameters at the end of the program area. This point stepped on the pit for 2 days to climb out of it, if you do not check the oscilloscope function test voltage value is not accurate.