The proposed programmer is based on a publication from the Radio magazine No. 2, 2004, “Programming modern PIC16, PIC12 on PonyProg”. This is my first programmer that I used to flash PIC chips at home. The programmer is a simplified version of the JDM programmer, the original circuit has an RS-232 to TTL converter in the form of a MAX232 chip, it is more versatile, but you can’t assemble it “on your knee”. This circuit does not have any active components at all, does not contain scarce parts and is very simple, it can be assembled without the use of a printed circuit board.

Rice. 1: Schematic diagram of the programmer.

Description of the scheme
The scheme of the programmer is shown in fig. 1. Resistors in the circuits CLK (clocking), DATA (information), Upp (programming voltage) serve to limit the flowing current. PIC controllers are protected from breakdown by built-in zener diodes, so some compatibility of TTL and RS-232 logic is obtained. In the presented circuit, there are diodes VD1, VD2, which “take away” positive voltage from the COM port relative to pin 5 and transfer it to the controller’s power supply, due to which, in some cases, it is possible to get rid of an additional power source.

Establishment
In practice, it does not always happen that this programmer will work without adjustment, from the 1st time, because. the operation of this scheme is highly dependent on the parameters of the COM port. However, on two Gigabyte 8IPE1000 and WinFast motherboards under XP, everything worked right away for me. If you are too lazy to deal with a non-working, more complex programmer circuit, then you should try to assemble this one. Here are some things that might affect:

The newer mat. board, the developers pay less attention to these ports, because these ports have long become obsolete. You can get rid of this by purchasing a USB-COM adapter, although again, the purchased device may not be suitable. The required parameters are as follows: the variable voltage must change at least -10V to +10V (log. 0 and 1) relative to the 5th pin of the connector. The output current must be at least such that when a 2.7 kΩ resistor is connected between the 5th pin and the pin under test, the voltage does not drop below 10V (I have not seen such boards myself). Also, the port must correctly determine the voltages coming from the controller, at a voltage level close to 0V, but not more than 2V, zero is detected, and, accordingly, at above 2V, one is detected.

Also problems can arise from the software.
This is especially true for LINUX OS, because due to the presence of emulators like wine, VirtualBox ports may not work correctly, and a lot of features are required from them. I will touch on these issues in more detail in another article.

Knowing these features, let's start building.
For this, it is highly desirable to have the ICProg 1.05D program.
In the program menu, you must first select in the settings resp. port (COM1. COM2), select JDM programmer. Then open the "Hardware Check" window, in the "Settings" menu. In this menu, you need to check the boxes in turn and measure the voltage at the contacts of the connected connector with a voltmeter. If the voltage parameters do not correspond to the norm, then unfortunately, this may be the cause of inoperability, then you will have to assemble a circuit with an RS-232 TTL converter. Having checked all the checkboxes, you need to make sure that a supply voltage of about 5V is formed on the zener diode. If the voltages are normal and there are no installation errors, then everything should work. We put the controller in the socket, open the firmware, program it. Checkboxes like "Invert data out" do not need to be enabled (all are unchecked). Also, do not forget that some batches of controllers may not have quite standard parameters, and they cannot be flashed, in such cases with this programmer you can only try to reduce the supply voltage from 5V to 3-4V by connecting the corresponding. zener diode, look at the controller for erroneous activation of the LVP mode (low voltage programming), how to prevent, you can read on the Internet for a specific type of controller. You can probably increase the programming voltage of a problem controller only by complicating the circuit by introducing an amplifier stage with a common emitter, powered from an additional power source.

Now more about the problem with the power supply of the device. The programmer was tested with ICProg programs and console picprog under Linux, it should work with anyone that supports JDM if you connect an additional power source (it is connected through a 1kΩ resistor to the zener diode, diodes with resistors in this case can be completely excluded). The fact is that the programmer control algorithms for individual software are different, the ICProg program is the most unpretentious. It was noticed that in Windows this program raised the required supply voltage on the unused pin 2, the same program under the emulator in Linux to another mat. The board was no longer able to do this, however, a way out was found by taking power from the programming voltage. In general, with ICProg, I think you can use this programmer without additional power. With other software, this is unlikely to be guaranteed, for example, the “native” from the Ubuntu picprog repositories without power simply does not detect the programmer, displaying the message “JDM hardware not found”. It probably either receives some data without applying the programming voltage, or does it too quickly, so that the filter capacitor has not yet had time to charge.

JDM programmer I used for controllers PIC16F676, PIC16F630 And PIC16F629. From the original, my version differs in that the programming voltage Vpp can be applied before the supply voltage vdd for reprogramming controllers. For this purpose, the upper transistor in the circuit is used. It opens when the voltage on pin 3 of the DB9F socket reaches approximately 8 V with respect to pin 5 of the socket, or 13 V with respect to the minus of the controller Vss. Switch Vdd_Vpp in the closed state allows the supply voltage vdd appear on the controller outputs before the programming voltage Vpp.

JDM Programmer Schematic

For programming, a COM port will be used, which will use the following pins - 3, 4, 5, 7 and 8. The circuit has the ability to program memory chips of the series 24cXX. To do this, the lower 8 contacts are used in the DIP16 block, the first contact of the microcircuit is inserted into the fifth pin of the block. Jumper J1 allows you to disable write protection.

The lower transistor in the circuit, as before, is used to shift voltages, since the plus power supply of the controller vdd connects to pin 5 of the socket - the common wire of the port, and minus the power Vss is obtained using diodes connected to pins 3 and 7 of the socket, and a zener diode.

Transistors in the JDM programmer used 2SC945 And BC548, diodes - 1N4148. Capacitor u1 should be placed as close as possible to the power pins of the microcontroller. The 1k resistor is optional if the 10k resistor and jumper J1 are installed on the DIP16 block.

This programmer successfully works with programs and

It just so happened that I started my acquaintance with microcontrollers with AVR. PIC microcontrollers for the time being, for the time being - bypassed. But, nevertheless, they also have unique, interesting to repeat, designs! But these microcontrollers also need to be flashed. I am writing this article mainly for myself. In order not to forget the technology, how to flash a PIC microcontroller without problems and senseless loss of time.

How to Program PIC Microcontrollers or Simple JDM Programmer

For the first circuit - I tried for a long time and hard to make a PIC programmer according to the circuits found on the Internet - nothing happened. It's a shame, but I had to turn to a friend to flash the MK. But this is not the point - to constantly run around acquaintances! The same friend also advised a simple scheme that works from the COM port. But even when I put it together, it still didn't work. After all, it’s not enough to assemble a programmer - you also need to set up a program for it, which we will flash. And this is exactly what I didn't get. A whole cloud of instructions on the Internet, and few of them helped me ...

Then, I managed to flash one microcontroller. But since I was flashing it under conditions of a severe lack of time, I didn’t think to save at least a link to the instruction. And after all, I did not find it later. Therefore, I repeat - I am writing an article in order to have my own instructions.

So, a programmer for PIC microcontrollers. Simple, although not 5 wires like for AVR microcontrollers, which I still use today. Here is the diagram:

Here is the circuit board ().

The COM connector is soldered with pins directly to the pads (the main thing is not to get confused with the numbering). The second row of pins is connected to the board with small jumpers (I said very incomprehensibly, yeah). I'll try to give a photo ... even though it's scary (I don't have a normal camera right now).
The most vicious thing is that for PIC microcontrollers, 12 volts are needed for firmware. And better not 12, but a little more. Let's say 13. Or 13.5 (by the way, experts - correct me in the comments if I'm wrong. Please.). 12 volts can still be obtained somewhere. Where is 13? I just got out of the situation - I took a freshly charged lithium-polymer battery, which had 12.6 volts. Well, or even a four-cell battery, with its 16 volts (I flashed one PIC this way - no problem).

But I digress again. So - instructions for firmware PIC microcontrollers. We are looking for the WinPIC800 program (unfortunately, the simple and popular icprog did not work for me) and configure it as shown in the screenshot.

After that, open the firmware file, connect the microcontroller and flash it.

It is the simplest design for flashing controllers of the PIC family. The undeniable advantages - simplicity, compactness, power without an external source of this classic programmer circuit made it very popular among radio amateurs, especially since the circuit is already 5 years old, and during this time it has established itself as a simple and reliable tool for working with microcontrollers.

Schematic diagram of the programmer for pic controllers:

Power supply for the circuit itself is not required, because the COM port of the computer is used for this, through which the microcontroller firmware is controlled. For low-voltage programming mode, 5v is enough, but all options for changing (fuses) may not be available. The connector for connecting the COM-9 port was mounted directly on the printed circuit board of the PIC programmer - it turned out very convenient.

You can plug the board without extra cords directly into the port. tested on various computers and when programming MK series 12F, 16F and 18F, showed high quality firmware. The proposed scheme allows programming PIC12F509, PIC16F84A, PIC16F628 microcontrollers. For example, recently, using the proposed programmer, a microcontroller was successfully flashed for.

For programming, WinPic800 is used - one of the best programs for programming PIC controllers. The program allows you to perform operations for microcontrollers of the PIC family: reading, writing, erasing, checking FLASH and EEPROM memory and setting configuration bits.

It is not a problem for many radio amateurs to quickly assemble a circuit they like on a microcontroller. But many beginners to work with microcontrollers are faced with the question of how to program it. One of the simplest options for programmers is the JDM programmer.

Program - programmer ProgCode v 1.0

This program runs on Windows XP. Allows programming PIC controllers of the medium family (PIC16Fxxx) via the computer's COM port. The programmer connection indicator (in the upper right corner of the window) in the absence of a programmer on the port selected in the settings turns red. If the programmer is connected, the program detects it and the indicator in the upper right corner takes the form shown in Figure 1.

The control panel is located on the left side of the program window. This panel can be minimized by clicking on the button in the toolbar or by clicking on the left edge of the window (this is convenient when the program window is maximized to full screen).

Figure (screenshot of ProgCode v1.0)


If a HEX file is loaded into the program, then it is advisable to first select the MK in the list of controllers for which the downloaded firmware is designed. If this is not done, then the file, designed for a microcontroller with a larger memory than selected in the list, will be truncated and part of the program will be lost - a warning is displayed with this file loading option.

If this does not happen, then you can select the desired controller after loading the file into the program.

SFR File Format

The ProgCode programmer supports working with its own file format. These files have the .SFR extension and allow you to store additional information about the program designed for the microcontroller. This file stores information about the type of microcontroller. This allows, when loading an SFR file, not to worry about pre-selecting the type of MK in the settings.

Port and protocol settings when connecting the programmer

After installing the program, by default, all settings are set that are necessary for the programmer to work with the JDM scheme shown on this page.
The signal inversion in the above circuit is only needed for the OutData output, since in this circuit the signal is inverted by the matching transistor. On all other outputs, inversion is disabled.



The pulse delay can be equal to 0. Its adjustment is provided for "particularly difficult" instances of controllers that cannot be flashed. The same applies to the write pause allowance - it is zero by default. If you increase the values ​​of these settings, the programming time of the controller will increase significantly.

The "check on write" checkbox should be checked if you need to "on the fly" check everything that is written to the microcontroller for correctness and compliance with the source file. If this checkbox is unchecked, the check is not performed at all and there will be no error messages, even if such errors actually exist.
Port speed selection - any speed can be selected. For the JDM programmer, this parameter does not matter.

WindowsXP uses buffering of information transmitted through COM ports. These are the so-called FIFO buffers. To avoid errors when programming through JDM, this mechanism must be disabled. You can do this in Windows Device Manager.

Go to the control panel, then:
Administrative Tools - Computer Management - Device Manager

Then we select the port to which the JDM programmer is connected (for example, COM1) - we look at the properties - the port settings tab - in addition. And uncheck the box "Use FIFO buffers"

Figure - Configuring the COM port to work with the JDM programmer



After that, we restart the computer.

Local Project Explorer

In addition to directly programming controllers, the program implements a convenient project browser for MK, located both on local computer folders and on the Internet. This was done for ease of use. Often, the projects you need are in different folders, and you have to spend time getting to the right directory to view the project. Here you can easily add the necessary folders to the list of folders and view any project with two or three mouse clicks.

Any file, when double-clicking on it in the browser panel, will open in the program itself - this applies to pictures, html files, doc, rtf, djvu (with plugins installed), pdf, txt, asm. The file can also be opened by double-clicking in the browser using an external program installed on the computer. To do this, the extension of the desired file type must be registered in the "File Associations" list. If you do not specify the path to the opening program, Windows will open the file in the default program (this is convenient for opening archives that do not always open unambiguously). If the path to the opening program is specified in the list, the file will be opened in the specified program. It is convenient to view files like SPL, LAY, DSN in this way.

Figure (screenshot of ProgCode v1.0 browser)



This is how the file association settings window looks like:

Web Project Explorer

The project browser on the Internet, as well as the local project browser, allows you to quickly go to the desired site on the Internet with a couple of clicks, view the project and, if necessary, immediately flash the program into the MK.



When reviewing projects on the Internet, if the project page contains a link to a file with the SFR extension (this is the file format of the ProgCode program), then such a file, when clicked on it, will open in a new tab of the program and is immediately ready for firmware into the microcontroller.
The list of links can be edited using the "Edit" button. This will open the window for editing the list of links:

Description of the chip programming process

Most modern microcircuits contain flash memory, which is programmed using the I2C protocol or similar protocols.
Rewritable memory is available in PIC, AVR and other controllers, memory chips like 24Cxx, and similar, various MMC and SD memory cards, ordinary USB flash cards that are connected to a computer via a USB connector.

Consider writing information to the flash memory of the microcontroller PIC 16 F 628 A

There are 2 lines DATA and CLOCK , through which it is transmittedinformation. Line CLOCK serves to supply clock pulses, and the line DATA to transfer information.

To transfer 1 bit of information to the microcontroller, you must set 0 or 1 (depending on the value of the bit) on the data line ( DATA) and create a voltage drop (transition from 1 to 0) on the clock line ( CLOCK).
One bit for the controller is not enough. He waits after five more to take this package of 6 bits as a command. The controller really likes commands, and they should consist of exactly 6 bits - this is the nature of the PIC 16.
Here is the list and meaning of the commands that the PIC is able to understand. There are not so many commands - the vocabulary of this controller is small, but one should not think that it is completely stupid - there are devices with fewer commands

"LoadConfiguration" 000000 - Load configuration

"LoadDataForDataMemory" - 000011 - Loading data into data memory (EEPROM)
"IncrementAddress" 000110 - Increase the address of the PC MK
"ReadDataFromProgramMemory" 000100 - Reading data from program memory
"ReadDataFromDataMemory" 000101 - Reading data from data memory (EEPROM)
"BeginProgrammingOnlyCycle" 011000 - Start programming cycle
"BulkEraseProgramMemory" 001001 - Complete erasure of program memory
"BulkEraseDataMemory" 001011 - Complete erasing of data memory (EEPROM)

The controller reacts to these commands in different ways. In different ways, after issuing the command, you need to continue the conversation with him.
In order to start a full-fledged programming process, it is also necessary to apply a voltage of 12 volts to the MCLR output of the controller, then apply a supply voltage to it. It is in this sequence of voltage supply that there is a certain meaning. After power up, if the PIC is configured to run from the internal RC oscillator, it can start executing its own program, which is not allowed when programming, as a failure is inevitable.
Pre-feeding 12 volts to the MCLR avoids this scenario.
When writing information to the flash memory of MK programs after the command

"LoadDataForProgramMemory" 000010 - Loading data into program memory

it is necessary to send the data itself to the controller - 16 bits,
which look like this:

“0xxxxxxxxxxxxx 0”.

The crosses in this word are the data itself, and the zeros around the edges are sent as a frame - this is the standard for PIC 16. There are only 14 significant bits in a word. This series of controllers has a 14-bit command representation format.
After the transmission of the data word is completed, the PIC waits for the next command.
Since our goal is to write a word to the MK program memory, the next command should be the command

"BeginEraseProgrammingCycle" 001000 - Start programming cycle

Having received it, the controller is disconnected from the outside world for 6 milliseconds, which it needs to complete the recording process.

The signals at the pins of the microcontroller are generated by a computer using special programs - programmers. COM, LPT or USB ports can serve for signal transmission. Programs such as PonyProg, IsProg, WinPic800 work with the JDM programmer.

Schematic diagram of the JDM programmer

A very simple programmer circuit is shown in the figure. In this circuit, although the control of the voltage supply sequence is not implemented, it is very simple and it is possible to assemble such a circuit very quickly, using a minimum of parts.
Figure (diagram of JDM programmer)

One of the questions when connecting the programmer to a computer is the question - how to provide selective isolation. In order to avoid damage to the COM port in the event of a malfunction in the circuit. Some circuits use the MAX232 chip, which provides selective isolation and signal level matching. In this scheme, the issue is resolved more simply - using battery power. The level of the signal coming from the computer is limited by the zener diodes VD1, VD2, and VD3. Despite the simplicity of the JDM programmer circuit, most types of PIC microcontrollers can be programmed with it.

The jumper between the pins COM6(DSR) and COM7(RTS) is designed so that the program can determine that the programmer is connected to the computer.

The connection of the programmer outputs to a specific MK depends on the type of MK. Often, several panels are mounted on the programmer board, which are designed for a certain type of controller.

The table shows the purpose of the legs of some types of MK during programming.

The PIC16F84, PIC16F84A microcontrollers have the same arrangement of pins for programming.

The pin assignment for microcontrollers of the PIC16Fxxx series, depending on the type of case, is standard in most cases, but if there is any doubt about this, then it is most reliable to check the datasheet for a specific instance of the MK. Part of the documentation is present on the Russian site http://microchip.ru The full collection of datasheets and other documentation is on the website of the manufacturer of PIC microcontrollers: http://microchip.com

Project Index

The program allows you to go directly to the index page, view the description of the desired project with a couple of clicks and immediately flash the program into the controller.



If necessary, flash the controller with the selected firmware - click on the SFR format file, for example Timer_a.sfr
The program downloads the file from the server in a new tab.



After that, it remains only to insert the MK into the programmer socket, if it has not already been done, and click on the "Write all" button.
The program is recorded in MK. After that, the controller is inserted into the device board and the device is ready for operation.