14 Jan 98, Jens.Madsen@post3.tele.dk writes to All: JM> I plan a RS232-powered Production Quality Programmer with folowing JM> capabilities: JM> 1. Meeting all Microchip Specification. The power is keeped low JM> enough (<1mA?) by resetting the PICxxxx, and then step fast until JM> desired address is reach, do programmings, and reset again when power is JM> needed. The Power is held on an electrolytic capacitor. The PIC's only JM> use very low power when reset is active. It's possible. Look for the COMPIC-1 technical background. JM> 2. The Programmer may be slow due to the low power consummation, JM> but the normal speed is as for a standard Production Programmer. This JM> is obtained by JM> a) Verification of the capable power on the capacitor, and JM> only reset the microchip and insert delays if needed. OK JM> b) Using that the typical current on RS232 may be higher and JM> the power used by the PICxxx typical are much lower than maximum JM> current. OK JM> 3) The Programmer should use an PIC16Cxx to control voltages, and JM> to verify if programming voltages are meet. The voltages for the JM> production programmer is generated by the microcontroler by JM> controling the average on an output pin. The Interrupts may not occur JM> exactly, and may be adjustet by reading the PIC's counter. Both Vcc JM> and Vdd is controled by the microchip, and both values is adjusted by JM> software. No external adjustment is needed and the adjustments are JM> burned into flash / eeprom. OK JM> 4) The Programmer should work with standard RS232 communication, JM> and the microchip controles it. The high values on Vdd is generated JM> by charge-pump, and verified by the chip. The charge-pump generages JM> 13V from +/-5V only, and it should work with all RS232 chips. You can found also +5V-only RS232 ports (some laptops). JM> 5) The Programmer should program all the microchips and is not JM> restricted to the serial programmable only. Almost impossible. Check specification for the PIC16C5X power consumption during programming - 30...50 mA @ 13.5V. Programmer will work at _very_ slow speed for this crystals. Check also specification for PIC17Cxx - you should manipulate 22 pins in programming mode. Another issue: Vcc for production quality programmer should be changed at least from 2.0V till 5.5V. You should have specfic level translators for all logic signals. JM> 6) The currents are verified to guarentee that the PICxxx is JM> inserted right in the socket, and to avoid problems if the chip is JM> shorted internaly. The check may be done when MCLR is low if it need JM> to guarentee low verification current. OK JM> 7) The Programmer does not depend on clock's from the PC, and it JM> is able to work with all platforms if software exist, and if needed. JM> (The Programmer was intended to work with a standard terminal JM> program). OK JM> I like to know if such a programmer is made, or if other is planing JM> to do it before I start to develope the programmer. Another one issue - commutation. Currently Microchip have 8 different incompatible pin layots: - PIC12Cxx - PIC16C54/56/58 - 18-pin mid-range (PIC16C61/71x/62x/8x) - PIC16C55/57 - PIC14xxx - 28-pin mid-range (PIC16C62/63/66/72/73/76) - 40-pin mid-range (PIC16C64/65/74/77) - PIC17Cxx New 14-pin PICs also announced and probably some another will be introduced in future. Production quality programmer should have one 40-pin ZIF (Aries or similar) and all commutation inside. It' looks like 40x28 analog commutation matrix with low ON resistance and full commutation, able to commutate current till 100 mA @ 14V. You should have another 10-12 pins for this matrix control, some pins for Vdd and Vcc setup, etc. - total about 50...60 control pins at the microcontroller. Yes, programmer, powered from COM port is very easy to use, especially with laptop in field, in car, etc. For example, COMPIC-1 programmer clones now manufactured at least by 3 companies and is very popular (I think, 1000+ already sold). However, COM port have very strong power limitation. Probably, in most situation, where production quality programmer should be used, external AC/DC 12V power supply will not be a problem. Best regards Alexey http://www.geocities.com/SiliconValley/Way/5807 ...more than 400 PIC-related links now