Sorry I hit the send button too fast. "As for the Vpp/Vpp sequence" should be "As for Vpp/Vdd sequence control" On 9/11/05, Xiaofan Chen wrote:=20 >=20 > I am talking about **Vpp**. What I mean is the Vpp voltage is rather=20 > constant=20 > for Wisp628 yet those JDMs will probably have big variations. > As for the Vpp/Vpp sequence, it is not probably not so easy for ICSP=20 > programmers if no Vdd control is possible. However ICD2 does not > even properly program the standalone 12F629 with internal MCLR and=20 > RC oscillator configuration. > Regards, > Xiaofan >=20 > On 9/11/05, Jan-Erik Soderholm wrote:=20 > >=20 > > HI. > > Just so there isn't any missunderstandings... > >=20 > > Chen Xiao Fan wrote : > >=20 > > > My guess is that Vpp are not really controlled in=20 > > > most JDM units... > >=20 > > Since you mentioned the Wisp628 in the paragraph before, > >=20 > > Note that the Wisp628 doesn't do that either "as-is". > > It needs a few extra components (as outlined on Wouters > > Wisp628 page), and then it simple shorts Vdd to GND > > a short period, which in itself puts some constraints > > on the power supply (no PSU with "soft-start-", not > > to many uF's on-baord). A 7805 based PSU with a few=20 > > 10's of uF has usualy worked for me. > >=20 > > I've been re-selling Wisp628's in Sweden for a couple > > of months, and I've had *three* customers locking themselfs > > out from 12Fxxx since then. All of them using the blink-a-led=20 > > test program (using intosc and int-MCLR) from Wouters page...) > > And since these are all PIC-beginners, well, it's not the > > best start they could get... :-) > >=20 > >=20 > > Jan-Erik. > >=20 > >=20 > >=20 > > -- > > http://www.piclist.com PIC/SX FAQ & list archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist > >=20 >=20 > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist