Here I am again. Although there are examples on the Internet, I have tried many ways but still can't solve it.

kisssibaby

Here I am again. Although there are examples on the Internet, I have tried many ways but still can't solve it. [Copy link]

My graduation project is to make a single-chip microcomputer. The address of the last help post is this https://bbs.eeworld.com.cn/thread-487710-2-1.html I learned slowly and did it slowly, and then built a minimum system according to this. I also have a passive crystal oscillator, a capacitor, and a reset. After connecting it to the computer with a USB to 232 interface, the author wrote a C language program and wanted to use the STC burner to write it in to test the waters, but the first step hung here I have been detecting the single-chip microcomputer, tried cold start, and adjusted the highest and lowest baud rates, but I can't figure it out. I want to ask the master for help

tianshuihu

Please post the hardware connection diagram.

kisssibaby

This is the actual picture. The breadboard I used has the positive and negative wires opposite to the positive and negative markings on the breadboard because I plugged in the power module.

kisssibaby

tianshuihu posted on 2016-4-21 14:37 Please post the hardware connection diagram

Can someone please help me?

tianshuihu

Why is there no power supply to the VCC pin 40?

tianshuihu

Pin 31 is connected to VCC. Why are the three pins 18, 19, and 20 so close to each other so far away? Why?

tianshuihu

"Use USB to 232 interface to connect to the computer" - need to share the ground. I don't seem to see you connect the serial port.

kisssibaby

tianshuihu posted on 2016-4-21 16:09 "Use USB to 232 interface to connect to computer" - need to share ground. I don't seem to see you connect the serial port

Shared ground, I was afraid that there were too many wires and I couldn't see clearly, so I removed it when taking pictures. I saw on the Internet that when writing to the microcontroller, don't connect the power supply vcc pin, so I didn't connect it.

tianshuihu

"I saw on the Internet that the power supply VCC pin should not be connected when writing to the MCU" Don't take it out of context. The normal burning of the STC MCU must have a power-off and power-on process. After power-on, the power supply must remain stable to work normally.

kisssibaby

tianshuihu posted on 2016-4-21 19:08 "I saw on the Internet that when writing to the microcontroller, do not connect the power supply VCC pin." Don't take it out of context. The normal programming of the STC microcontroller must be powered off and then on...

Then I will try again

kisssibaby

tianshuihu posted on 2016-4-21 19:08 "I saw on the Internet that the power supply vcc pin should not be connected when writing to the MCU" Don't take it out of context. The normal programming of the STC MCU must be powered off and then on...

After the 40 pin is connected to the power supply, it still stays at the MCU detection point when burning the program:Sad:

tyyhzcm

Connect pin 20 to the negative pole of the power supply and the GND of the downloader. Connect the reset and crystal oscillator circuits according to the circuit diagram given by STC. Connect pin 40 to the positive pole of the power supply. Leave the positive pole of the downloader empty and do not connect anything. Connect the RXD TXD of the MCU and the downloader with different signs together. After clicking download, unplug the positive pole and plug it in again.

kisssibaby

tyyhzcm posted on 2016-4-21 20:34 Connect pin 20 to the negative pole of the power supply and the GND of the downloader. Connect the reset and crystal oscillator circuits according to the circuit diagram given by STC. Connect pin 40 to the positive pole of the power supply and the downloader...

I will modify the circuit and try it again tomorrow. I think it looks very refreshing. I plugged too many wires.

huo_hu

With the new model, all peripheral circuits can be saved, just connect the power supply

liaoyuanhong

Did you draw the board yourself? Or did you buy a development board online? Is the USB to 232 interface driver installed?

kisssibaby

liaoyuanhong posted on 2016-4-22 18:01 Did you draw the board yourself? Or did you buy a development board online? Is the USB to 232 interface driver installed?

I bought a development board for reference, but my teacher insisted that I build one myself. I used a breadboard and installed the driver. The stc burner can detect the USB port, but it just stays at the detection of the microcontroller.

kisssibaby

huo_hu posted on 2016-4-22 11:43 If you use the new model, you can save all the peripheral circuits and just connect the power supply

Does the new model refer to the microcontroller? Are there any recommended microcontroller models? What I want to do is transparent transmission between the microcontroller and the gprs module. Please recommend some.

huo_hu

kisssibaby posted on 2016-4-22 18:50 New model, does it mean single-chip microcomputer? Are there any recommended single-chip microcomputer models? What I want to do is transparent transmission between single-chip microcomputer and gprs module. Please recommend one...

12C series are all OK, they are compatible. 89 series is a very old model.

kisssibaby

huo_hu posted on 2016-4-22 19:30 12C series are all OK, they are compatible. 89 series is a very old model.

I reconnected the line and it is better than before. Please help me see if there is any problem with the wiring.

huo_hu

kisssibaby posted on 2016-4-22 21:33 I reconnected the line and it is better than before. Please help me see if there is any problem with the wiring

Oh, the stc15f directly simulated by hardware is a chip suitable for beginners. There is no need to go back to 10 years ago.