Single-Chip Microcomputer entry guide series (8) Use a bread to build an experimental circuit

This article is original by purplesword (jzj1993). For more information, see. Original web site http://blog.csdn.net/jzj1993

We have introduced several solutions for preparing the experiment board. Here we will first introduce solution 1. I will build a simple single-chip microcomputer lab Board together with you to enjoy hands-on practice.

We have two ways to build our own lab board. One is to use a bread board, and the other is to use a universal welding board. In this article, we will introduce how to build a circuit.

A bread is a kind of equipment used for circuit experiments. It has a lot of holes on it. We can insert components and wires into it to form the circuit we need. If a circuit error is found, unplug the component and wire and plug in again. After the circuit is completed, all components can be pulled and used again.

It is easy to set up the circuit of the bread, saving time and materials. However, the disadvantage is that the bread can only be used to build some relatively simple circuits that do not require high electrical connections. If the circuit is too complex and there are all kinds of wires on the bread board, some wires or components may be loose and it is not easy to find. If some circuits have high requirements on electrical connections, such as high current, weak Signal Processing, high-frequency circuit, etc., because the components are simply inserted in, and the resistance value between them is large, the effect is not ideal.

Display of the bread line and a common bread board. You can use common hard wires with proper thickness or the dedicated cables shown in the figure.

In the figure, the entire vertical bars marked with red lines and blue lines on the outside are connected separately. They are generally used for power supply. Each of the five holes in the middle is connected together and used to connect various components.

　　

Next we will go to the topic to build a simple single-chip microcomputer lab board. We have introduced that the minimum system circuit of a single-chip microcomputer is the minimum circuit for the normal operation of the single-chip microcomputer. Here we will start from the minimum system. Prepare the following tool materials:

Crumb, crumb wire, wire, and DuPont Wire

RC Single-Chip Microcomputer in the dip40 package (both can be X)

11.0592mhz crystal oscillator and 30pf capacitor (for clock circuit)

10uf capacitor, 10 K resistor (for Reset Circuit)

USB-TTL download line (for program burning, will be detailed in the following articles)

Six-pin self-locking switch (as a power switch, it can be omitted, instead of plugging the wire)

　　

The elements in the figure are used to reset the circuit and clock circuit. The above is a 10 k Color Ring Resistance, please learn the specific reading method; then the 10uf point uncapacitor, electrolytic capacitor has a positive and negative, the skin is marked with a white arrow on the pin as the negative, if it is a brand new electrolytic capacitor, the positive electrode pin is longer; there are two ceramic capacitors on the left below, I did not find 30pf I use 27pf is relatively close to the replacement, the specific capacity reading method please also learn; in the lower right corner, the crystal oscillator is marked with 11.0592 on the front, that is, the crystal oscillator frequency is 11.0592 MHz.

　　

The figure shows the minimum system built. The two white lines are used to connect the positive and negative ends on both sides.

　　

Dubang line of one end of the Public head (PIN) and one end of the mother head (Jack)

　　

USB-TTL adapter front

　　

Opposite side of USB-TTL adapter Board)

　　

Dubang line mother connected to the USB-TTL adapter Board (hereinafter referred to as the adapter Board), dubang line of the Public head inserted in the bread board and the minimum single chip microcomputer system connected. The power supply of the 5 V connection to the bread board on the adapter Board (My adapter board has two power supply voltages: 5 V and 3 V, and some adapter boards only have one VCC and connect them to the VCC). Gnd is connected to the negative end of the bread board, that is, the Gnd of the single chip microcomputer. These two wires can supply power to the single chip microcomputer. The txd on the adapter board connects the single chip microcomputer rxd (p3.0) and the rxd connects the single chip microcomputer txd (p3.1) (refer to the 51 Single-Chip Microcomputer pin distribution diagram previously introduced). These two lines are used for serial communication and download programs, which will be detailed later.

As shown in the figure, I have connected the circuit, connected a LED and resistor on p1.0, and downloaded the LED flashing program from the computer. You can see that the green led in the photo is being lit.

After setting up the lab board, I will take you to install the relevant software, write the first single chip microcomputer program, and download it to our lab board for running.

Single-Chip Microcomputer entry guide series (8) Use a bread to build an experimental circuit