Self-made writer

Self-made simple 51 microcontroller Programmer (writer)

AT89C51 is the most widely used 8051 Single-Chip Microcomputer. More importantly, it has the characteristics of repeatedly burning (flash. Generally, 1000 times can be repeatedly written, which provides a cheap platform for beginners to test. In order to meet the needs of the majority of single-chip microcomputer enthusiasts, I took half a month to reference foreign materials, the actual design and production of a simple AT89C51/52/55 single-chip computer programmer. Due to the different programming time series of single-chip microcomputer, this programmer only supports the Atmel Company's AT89C51, AT89C51, and AT89C51 55 chips, and does not support WINBOND or Philips compatible chips. The following is a single-chip programming circuit diagram.

Note: For a list of components, see the appendix.
Brief description of Working principle:

 

Q2, Q4 and the surrounding components constitute a level conversion circuit, which saves one piece of MAX 232 chip. In the case of low requirements, this circuit can replace maxcompute in single chip communication. Q1, R2, R4, dw2, and four components provide a 12 V voltage for the programmer. R4 and R2 constitute a partial pressure circuit. In normal times, * 13th chip 89C51 (P3.3) output High Level, Q1 conduction, R2 (1 k) Will dw2 (12 V) Down, at this time dw2 voltage from R4, R2 partial pressure, about 3-5 V; when writing a program, the * chip 13th foot (P3.3) Outputs a low level, Q1 cutoff, dw2 (12 V) directly sends to the 31 foot of the burned chip, thus providing a burning voltage. The programming tool burning Voltage provided by the official Atmel website is adjusted with LM317 and uses two high-precision resistors. The circuit is complex and costly, this circuit is proved to be stable and reliable by experiments with hundreds of users.

The power supply transformer must be 15 V power supply, for example, the common 3-12 v dc adjustable power supply, note that the no-load voltage should be less than 13 V, the filtering should be better, otherwise the programming may be unreliable.
* The chip is installed on the IC seat. Find a programmer and write the * program ez51.hex and insert it to facilitate debugging. If it is difficult to purchase a card holder, you can directly use an IC seat. Connect the cable with a string of 9 to 9 male and a mother. Note that there are two or three cross ports on the market. It is best to use a multimeter to check whether there is a one-to-one correspondence. If you do not have a serial line, you can also split an old-fashioned serial port with the mouse, as long as the two ends are connected with 2, 3, 5 feet. This circuit has no special requirements on components. The resistance should be 1/8 W ordinary carbon film. I use 2sa1015 and 2sc1815 for the transistor. In fact, many small power tubes can be used, such as 9014,9015. You just need to pay attention to the difference in pin arrangement.
The diode 1n4148 can be replaced by 1n4004. In addition, it is best to select a 12 V pressure regulator with an accuracy of less than 5%. If the 11.0592m crystal has the conditions, we should test that the retail crystals in the market are not vibrating.
This programming tool burn write software ez31.exe interface is very simple; fully compatible with the WINDOWS9X-2000. There are only a few buttons: Open File (send), read chip (read), exit (exit), com selection, lock code, and check (fast verily ). You will know it at a glance. Note that the upgraded version ez4.0 is now available for automatic monitoring of port numbers and chips. Easy to use!DIY installation steps:

1: Installation resistance, a total of 11; component inserted in place after welding shear pin:
2: Install diode, three 1n4148 and one 12 V voltage regulator dw2. Please take a closer look at the surface of the tube with words: the steady pressure tube is printed with 12 V. Do not confuse it. The diode is polar, And the blackhead of the diode is inserted to the white side of the PCB. Right: After the component is inserted in place, weld the scissors:

3: Install 2 104 and 2 30p capacitors; 11. 0592 crystals, none of which have any direction plug:
4: Insert a transistor. Electrolytic Capacitor, luminous tube: note that these things are polar: if you reverse it, it will not work. Electrolytic capacitors and luminous tubes are easy to handle. They are both negative and downward. Transistor (two 2sc1815, one 2sa1015,) and one 78l05 regulator IC: they can be seen on the PCB, and the butt is in the half circle direction.

5: insert exclusion (one end of a white point is the public end, and its position is close to the source end of the PCB edge; power socket, 232 socket is needless to say.
6: plug the * chip socket.
7: plug-in and write the seat. Since he and * The chip are face-to-face, he must first weld * The chip socket, and finally burn and write the clip seat. Otherwise, it will be difficult to change the soldering iron.
8: if you do not know how to remove components, please open your eyes and take a closer look at the picture above.
9: Check whether there is an error or short circuit in each part of the circuit board. Then, follow the preceding debugging method to debug. If no error is inserted, you can call OK once.

Debugging:

Power-on after assembly, check with A multimeter:
1, 7805 output 5 V, D2 power indicator light on. (I used 78l05 in the figure)
2. The dw2 voltage is 3-5 V.
4. Connect the base pole of Q1 to the ground, and the dw2 voltage is 12 V.
5, U1 (89C51) 2.2, 19 feet voltage is 2.1 V, V, this voltage can be used as the basis for the circuit vibration.
Connect the power supply and Serial Line of the programmer, insert the burned chip, and click COM1 or com2 (in this example, I connect to com2 ), the lower right corner of the window shows 89c51found. At this time, we should see that the signal indicator D6 is on every 2 seconds, indicating that it works online.
Select a HEX file that needs to be burned to start writing. If everything is normal, the displayed interface is shown in.
Dual-panel super small PCB; note that * the chip is installed on the back side of the chip. Therefore, the entire circuit board is only a little bigger than the match box. It may be the most compact programmer you can see. Is it very beautiful?

Take a look at this picture: You must have decided! A total of less than 30 parts, really Ez, according to the assembly of a plug-in to the welding test only half an hour.
Appendix: component list
Part type designator footprint
1 K r19 axial0.3
1 K R2 axial0.3
1n4148 D5 diode0.4
1n4148 D1 diode0.4
3 K R3 axial0.3
3 K R4 axial0.3
4k7 R13 axial0.3
4k7 R11 axial0.3
4k7 R8 axial0.3
10 K * 8 R18 (row resistance)
10 K R7 axial0.3
10 K R6 axial0.3
10 K R5 axial0.3
10 UF C8 rb.2/. 4
10 UF C14 rb.2/. 4
10 UF C7 rb.2/. 4
10 UF C6 rb.2/. 4
11.0592 M xt2 rad0.2 (crystal)
12 V dw2 (Pressure Control Tube)
15 V in 7257 (power input socket)
18 K R12 axial0.3
30 p C15 rad0.1
30 p C16 rad0.1
104 C4 rad0.1
104 C5 rad0.1
A1015 Q4 to-126
C1815 Q1 to-126
C1815 Q2 to-126
In4148 D4 diode0.4
Led D2 rb.2/. 4 (Light Emitting Diode)
Singal D6 rb.2/. 4 (Light Emitting Diode)

DB9 232 socket
40pin burning and writing seat
40pin IC (for plug * chips)
232 string line
PCB
89C51 * Chip
15 V power supply