USB Pic Programmer
USB Pic Programmer
This post is dedicated to anyone who wants to program a PIC (microchip) device via USB. While browsing the web for ready-to-use projects, I found a nice project called Open Programmer, which has several schematics, PCBs, and open source code. Source link: http://openprog.altervista.org/OP_ita.html.
What bothered me was the need to install a special socket board on the motherboard depending on the model of the PIC being programmed. Moreover, the proposed layout did not match my personal ideas of a “compact look”. So, in the following, I propose a small version of this circuit with one smart built-in ZIF socket. This version sacrifices many models of non-PIC microcontrollers. I will be grateful to anyone who offers a wider range of implementation suitable for programming Atmel and other devices. In any case, if your goal is to program PIC devices, you are on a good site.
A small box, a USB connector, a ZIF connector, two LEDs. That’s all in my compact offer.
Description
Details are available in the original project mentioned above. Below I have shown my compact version with schematic, PCB layout and instructions for assembling and inserting it into a very basic plastic box. At the bottom of this page I provide a copy of the PIC18F2550 download program used to control the programming functions, as well as a copy of a third-party PC program. I have tested the program up to Win-8 without problems. Note that a newer version of the firmware and software is available on the original site.
Implementation and assembly
First assemble the main module using low profile components that are no more than 10mm above the PCB surface, as the second board will be mounted above this board. Install 4 columns that are ten millimeters high to allow for final assembly of the second board. Use low profile parts to attach the columns, otherwise manual metal removal may be required to reduce the copper side.
ZIF is a fairly thin component to solder in the end. Take care to avoid any force that could cause damage or deformation. It is better to make holes of 1.2 mm diameter to facilitate insertion of the ZIF socket into the PCB. When soldering, jump several contacts at a time, following a spiral line, using a sequence that allows you to heat up the contact while you solder the next one.
Once the two circuits are complete, connect them using striplines and block the assembly using columns. Use countersunk screws for the countersunk holes to ensure that the screws are not too high relative to the top surface of the second PCB. Only the socket and two LEDs should appear.
The plastic box is very common. You have to create holes to allow the parts coming out of its surface: a connector, two LEDs (or one bi-color LED), a USB connector on the short side. It is a female type A
After a few tries and corrections you will reach the final result. There is a frame on the cover that needs to be modified to accommodate the circuits, but your logic will guide you. The first PCB should be secured to the box using the screws provided.
Here and below is the final result:
Software
As mentioned earlier, the original site offers both firmware and PC software. In any case, to start using this programmer, I suggest you use the versions I used while editing the project, available below for download. After some tests, you can try the new updated versions available on the original site. Of course, if you don’t have a programmer yet, your friend should program it first. After this first step, you’ll be a car!
Usage
Connect the programmer to the PC using a USB-A cable. The device is considered universal. The green LED first blinks quickly, indicating the current connection. Than slowly, indicating the end of the connection phase. The PC software allows the bots to write and read the EEPROM of any PIC installed on the ZIF toe. Test functions allow you to measure the high voltage Vpp generated by the step-up converter present in the main circuit. This voltage is already checked by the firmware itself anyway.
The programmable PIC should be located on the ZIF socket as shown in the following figure.
