Rochester, 28 december 2007. 2007/12/26, Xiaofan Chen : > > On 12/27/07, Richard Caldwell wrote: > > Hi, further to my zener issue I'm having the following problem > > when driving the data line high/low (step 6 of El Cheapo windows > > interface v0.84). At step 3 I get 13.42V. At step4 I get 4.89V which > > should be close enough. At step 6 I've the following problem, > > when driving the data line high I get 3.58V and low I get 1.45V > > instead of the expected values. I'm getting these values even > > with the PSU disconnected which sugests I'm simply reading > > high/low values from the parallel port?? Can anyone suggest > > where my problem might lie? > > Can anyone suggest where my problem might lie? Make sure you use the most recent version of the El Cheapo implementation. There have been various updates, for both the PCB and the non-PCB version. If you use the PCB version, verify that the soldering didn't damage the lines on the board (the board is very sensitive to this). The problem is with El Cheapo or whatever it is called. At 13.42V, > the Vpp is too high for some PICs and this may permanently > damage some Flash PICs. There is no problem with the El Cheapo. I've used it many times with success. As long as you only program the set of devices that it is meant to work with, you will have no issues. I succesfully used it with the 16F877, the 16F628 and the 16F84A. ic-prog has an extension for it, and it may be able to program the 16F88 using that. Sadly, it does not program the 16F877A and the 16F628A. Also note that the El Cheapo can program a number of parts (especially in the C series) that the Pickit 2 can not. I am not saying El Cheapo is better than the Pickit 2, however, it does have its own power supply, and it works well for the devices it was designed for. I did, however, eventually switch to the Pickit 2. Greetings, Maarten Hofman. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist