AT89C51 is one of the most widely used 8051 microcontrollers, and more importantly, it has the characteristics of repeated programming (FLASH). It can be reprogrammed 1000 times in general, which provides a cheap platform for beginners' experiments. In order to meet the needs of the majority of SCM enthusiasts, I use two weeks of time, reference to foreign data, the actual design of a simple successful AT89C51/52/55 microcontroller programmer. Due to the different programming timing of the SCM, this programmer only supports ATMEL's AT89C51, AT89C52, AT89C55 chips, does not support Winbond or Philips compatible chips.
For many electronic enthusiasts like me who are not too young from the beginning of the 80s to assemble 7-inductor semi-conductor radios, facing the MCU seems to be a bit paradox, but in fact I think he is even simpler than assembling a radio: Is its hardware circuit diagram, a little bit of patience, you can use the breadboard welding.
In order to facilitate everyone's production, I simplified the circuit design:
Q2, Q4 and surrounding components constitute the level conversion circuit, which saves a max 232 chip. In places where the requirements are not high, this circuit can replace the MAX232 in the microcontroller communication.
The Q1, R2, R4, DW2, and 4 components provide programmers with 12V for programming. Among them, R4 and R2 form a voltage divider circuit; normally, the 13th pin (P3.3) of the monitoring chip 89C51 outputs a high level. Q1 is on and R2 (1K) pulls DW2 (12V) low. At this time, DW2 voltage is divided by R4 and R2 and is about 3-5V. When writing a program, monitor pin 13 (P3.3) output. Low level, Q1 cuts off, DW2 (12V) Sends directly to 31 feet of burned chip, thus offer and write the voltage. The programmer's programming voltage provided by ATMEL's official website is adjusted by the LM317, and uses two high-precision resistors. The circuit is complex and costly. The circuit has been proved to be very stable and reliable after hundreds of experiments.
The power transformer requires a 15V power supply, such as a common 3-12V DC adjustable power supply. Note that the no-load voltage should not be lower than 13V and the filtering should be better, otherwise the programming may become unreliable.
The monitoring chip is installed with an IC holder. In addition, a programmer is programmed to burn the monitor program EZ51.HEX and then inserted for easy debugging. If you have difficulty buying, you can use an IC card directly. Power up after assembly and check with a multimeter:
1,7805 output 5V, D2 power indicator light. (I'm using 78L05 in the picture)
2, DW2 voltage is 3-5V.
4. The base of Q1 is shorted to ground. The voltage of DW2 is 12V.
5, U1 (89C51) 18,19 pin voltage is 2.2V, 2.1V, this voltage can be used as the basis for the start-up circuit.
Connect the cable to a 9-to-9-mother serial cable. Note that there are some serial ports on the market where the 2 and 3 pins are crossed. It is best to use a multimeter to check whether it is a one-to-one correspondence. If you do not have a serial cable, you can also remove an old serial mouse and make it as long as you connect the 2, 3, and 5 pins. This circuit has no special requirements on the components. Resistors use 1/8W ordinary carbon film. The transistor I use is 2SA1015, 2SC1815. In fact, many small power transistors are available, such as 9014 and 9015. Just need to pay attention to the difference of their pin arrangement. Diode 1N4148 can be replaced with 1N4004. Another 12V regulator is best to choose, accuracy requirements within 5%. If the 11.0592M crystal is conditional, it should be tested. The crystals in the retail market may not work.
The programmer's programming software EZ31.EXE interface is very simple; fully compatible with Windows9X-2000. There are only a few buttons, which are SEND, READ, EXIT, COM selection, LOCK CODE, and FAST VERILY. Big home will know it. Note that the download version of ez4.0 automatically monitors the port number and chip for its updated version. Use more simple!
Connect the programmer's power supply and serial cable, and insert the programming chip. Click COM1 or COM2 (according to the actual connection, in this case, I'm connecting to COM2). The lower right corner of the window shows 89C51Found. At this point you should see the signal indicator D6 light up every 2 seconds, indicating online work.
Select a hex file that needs to be programmed to start programming. If everything is normal, the interface shown above is shown.
Dual-panel super-small PCB; note that the monitoring chip is mounted on the opposite side. So the entire circuit board is just a little bigger than the matchbox, and probably the smallest programmer you can see. Isn't it pretty?
Look at this picture: Presumably you must do it! A total of less than 30 parts, it is indeed ez, according to the assembly of a plug-in to the welding test as long as half an hour.
Component list
Part Type Designator Footprint
1K R19 axial0.3
1K R2 axial0.3
1N4148 D5 diode0.4
1N4148 D1 diode0.4
3K R3 axial0.3
3K R4 axial0.3
4K7 R13 axial0.3
4K7 R11 axial0.3
4K7 R8 axial0.3
10K*8 R18 (row resistance)
10K R7 axial0.3
10K R6 axial0.3
10K R5 axial0.3
10UF C8 RB.2/.4
10UF C14 RB.2/.4
10UF C7 RB.2/.4
10UF C6 RB.2/.4
11.0592M XT2 rad0.2 (crystal)
12V DW2 (Regulator)
15V IN 7257 (power input socket)
18K R12 axial0.3
30P C15 RAD0.1
30P 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
LEDD2 rb.2/.4 (Light Emitting Diodes)
SINGAL D6 rb.2/.4 (Light Emitting Diodes)
DB9 232 socket
40PIN programming card holder
40PIN IC Block (for monitoring chip)
232 serial line
PCB
89C51 monitoring chip
15V power supply
DIY installation steps:
1: Install resistors, a total of 11; after the component is inserted in place, the welding shear leg:
2: Install the diode, three 1N4148 and one 12V regulator DW2. Please look carefully at the surface of the tube: The Zener tube is printed with 12V. Don't confuse it. The diode is polarized. The black side of the diode is plugged into the printed white side of the pcb: the component is inserted in place and the solder leg is cut:
3: Install two 104 and two 30p capacitors; 11.0592 crystals, these are no directivity to insert:
4: Insert the transistor. Electrolytic capacitors, luminous tube: Note that these things are polar: If you do it, you can't do it. Electrolytic capacitor and LED are very easy to do, both are negative down. Transistors (two 2SC1815, one 2SA1015, and one 78L05 regulator IC): Their direction can be seen on the PCB, the direction of the butt is half-circle.
5: insert exclusion (exclusion with a white point of the common end, his position near the source of the PCB side; the power outlet, 232 socket Needless to say.
6: plug into the monitor chip.
7: Insert and burn the card holder. Because he and the monitor chip are face to face, the monitor chip socket must be soldered first, and then the card must be soldered. Otherwise it will not move the soldering iron.
8: If you really do not clear the direction of the components, please take a close look at the photo above.
9: Finally, check whether the circuit board has any wrong insertion or short circuit. Then follow the debugging method above. If not inserted wrong
Basically OK once OK
High Voltage Component - Resistor, High Voltage Compoment - Capacitor, HV Film Capacitor for Power Supply
XIAN STATE IMPORT & EXPORT CORP. , https://www.shvcomponents.com