Reads and writes hex8 and hex32 files, and also binary in case of serial memories. If not otherwise specified the program looks for an USB device with vid&pid=0x4d8:0x100. If after plugging the device /dev/usb/hiddevX is inexistent (and LED2 doesn't blink at 1 Hz), it's sufficient to execute a few times lsusb to force enumeration, or unplug and replug the cable. If you want to enable a user group write:

To permanently enable a user do the following (on Ubuntu and other Debian based distributions, check for others):Īs root create a file /etc/udev/rules.d/les The Linux version searches the programmer between devices /dev/usb/hiddevX (or the one specified as parameter) and needs reading rights for it. OP is a command-line executable the Windows version doesn't need installation Here a version for 18F2450 (with reduced functionality, see the circuit).Ĭommand-line utility (Linux and Windows, v0.7.9) Here is the complete MPLAB project, here the hex file only.

It's certainly possible to compile with SDCC, but some changes are needed to the source code.Įverything is given under the GPL2 license. The main control cycle waits for a packet from USB, then executes commands in sequence while managing communication tasks at the same time a control function is called periodically by a timer interrupt and keeps the DCDC regulator output voltage constant.īuilding the project requires only free programs: MPLAB and MCC18 student version, which are unfortunately only available for the windows (in)operating system. My programmer code simply adds a command interpreter that drives the microcontroller's outputs according to a set of instructions. I wrote a brief guide on how to use it to my knowledge this is the only open source firmware with HID support and GPL license. The USB firmware comes from a nearly unknown open source project, written by Alexander Enzmann, which I modified and adapted to the MCC18 compiler. The programmer appears to the system as a HID device that exchanges 64 bytes packets every 1 ms. Like all USB devices this one too has a vid and a pid these are usually obtained under payment, but since I don't have any money to waste and I'm not selling a commercial product I used the default Microchip vid and a pid of choice: 0x4D8&0x100 anyways it's possible to configure both, so I leave the choice to the user.

Maximum allowed speed is 64KB/s, although with my application I measured something in the range 20-40 KB/s, certainly enough to program devices with memory of 100KB at most. In order to use the USB interface included in some PIC devices we need a firmware that implements one of the classes defined by the USB consortium or a new one I opted for the HID class, which is supported natively by all operating systems and so doesn't need any driver.

18f252 tait programmer