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I have uploaded this version to the files area. I also uploaded a picture of the required circuitry. This circuitry is already implemented on the IAR Kickstart and Keil MCB2100 evaluation boards. It is really handy as ISP development can be done relatively quickly and "hands-off". Cheers Richard |
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LPC210x Flash Utility with RTS/DTR Control
Started by ●February 5, 2004
Reply by ●February 5, 20042004-02-05
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Hi Richard, i think the position of D3,4 is wrong. What happens when DTR or RTS are '1' (negative voltage)? You better place D3,4 behind the 33k resitor to protect the drivers of your PC. Andreas --- In , "Richard" <richas@y...> wrote: > I have uploaded this version to the files area. I also uploaded a > picture of the required circuitry. This circuitry is already > implemented on the IAR Kickstart and Keil MCB2100 evaluation boards. > It is really handy as ISP development can be done relatively quickly > and "hands-off". > > Cheers > > Richard |
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Reply by ●February 5, 20042004-02-05
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Yes, shift those right one resistor. :-) Richard --- In , "haack0815" <lpc_arm@s...> wrote: > Hi Richard, > > i think the position of D3,4 is wrong. > What happens when DTR or RTS are '1' (negative voltage)? > You better place D3,4 behind the 33k resitor to protect the drivers > of your PC. > > Andreas > > --- In , "Richard" <richas@y...> wrote: > > I have uploaded this version to the files area. I also uploaded a > > picture of the required circuitry. This circuitry is already > > implemented on the IAR Kickstart and Keil MCB2100 evaluation boards. > > It is really handy as ISP development can be done relatively quickly > > and "hands-off". > > > > Cheers > > > > Richard |
Reply by ●February 5, 20042004-02-05
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While a good idea from an engineering perspective, remember that RS-232 drivers are meant to survive dead shorts, including shorting a high line to a low line (+12 to -12). The circuit may not function correctly, but it won't (shouldn't) blow the driver. --jc haack0815 wrote: > Hi Richard, > > i think the position of D3,4 is wrong. > What happens when DTR or RTS are '1' (negative voltage)? > You better place D3,4 behind the 33k resitor to protect the drivers > of your PC. > > Andreas > > --- In , "Richard" <richas@y...> wrote: > > I have uploaded this version to the files area. I also uploaded a > > picture of the required circuitry. This circuitry is already > > implemented on the IAR Kickstart and Keil MCB2100 evaluation boards. > > It is really handy as ISP development can be done relatively quickly > > and "hands-off". > > > > Cheers > > > > Richard |
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Reply by ●February 5, 20042004-02-05
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I fixed the schematic. Thanks for the heads-up. Richard --- In , "J.C. Wren" <jcwren@j...> wrote: > While a good idea from an engineering perspective, remember that > RS-232 drivers are meant to survive dead shorts, including shorting a > high line to a low line (+12 to -12). The circuit may not function > correctly, but it won't (shouldn't) blow the driver. > > --jc > > haack0815 wrote: > > > Hi Richard, > > > > i think the position of D3,4 is wrong. > > What happens when DTR or RTS are '1' (negative voltage)? > > You better place D3,4 behind the 33k resitor to protect the drivers > > of your PC. > > > > Andreas > > > > --- In , "Richard" <richas@y...> wrote: > > > I have uploaded this version to the files area. I also uploaded a > > > picture of the required circuitry. This circuitry is already > > > implemented on the IAR Kickstart and Keil MCB2100 evaluation boards. > > > It is really handy as ISP development can be done relatively quickly > > > and "hands-off". > > > > > > Cheers > > > > > > Richard > > > > |
Reply by ●February 7, 20042004-02-07
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Richard, Can you check this schematic again? On a DB-9, pin 4 is DTR and pin 7 is RTS. These are reversed on the schematic. Is DTR intended to drive P0.14 or /RST? --jc Richard wrote: > I have uploaded this version to the files area. I also uploaded a > picture of the required circuitry. This circuitry is already > implemented on the IAR Kickstart and Keil MCB2100 evaluation boards. > It is really handy as ISP development can be done relatively quickly > and "hands-off". > > Cheers > > Richard |
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Reply by ●February 8, 20042004-02-08
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Hi jc, the DTR signal drives the Reset signal and RTS is used for P0.14 Andreas --- In , "J.C. Wren" <jcwren@j...> wrote: > Richard, > > Can you check this schematic again? On a DB-9, pin 4 is DTR and pin > 7 is RTS. These are reversed on the schematic. Is DTR intended to > drive P0.14 or /RST? > > --jc > > Richard wrote: > > > I have uploaded this version to the files area. I also uploaded a > > picture of the required circuitry. This circuitry is already > > implemented on the IAR Kickstart and Keil MCB2100 evaluation boards. > > It is really handy as ISP development can be done relatively quickly > > and "hands-off". > > > > Cheers > > > > Richard |
