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Tommy Tyler Expert
Joined: 21 Sep 2003 Posts: 412 Location: Denver mountains |
Posted: Sun May 13, 2012 8:20 pm Post subject: Another Low-Cost JP1.2/3 (Flash) Interface |
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Here's another way to make your own flash interface, not the best, but probably the least expensive that uses an FTDI chip and driver. And it does top the Nokia and FTDI Cable versions in that you can have an LED diagnostic indicator if you want it.
The instructions are HERE. |
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jetstar52
Joined: 16 Oct 2003 Posts: 177 Location: Sacramento, CA |
Posted: Mon May 14, 2012 11:50 am Post subject: |
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Amazing! Thanks so much for your continuing help to this community. I noticed in your instructions that there's no need to connect pin 1. I have a modified 15-100 whose six-pin header came off due to wear and mishandling. Can I ignore pin 1 when I reattach the 15-100's header? If I leave pin 1 unconnected, can I still use the earlier cable I bought from you? _________________ I used to have 5 remotes that controlled one thing each. Now I have 6 remotes that each control everything! |
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Tommy Tyler Expert
Joined: 21 Sep 2003 Posts: 412 Location: Denver mountains |
Posted: Wed May 16, 2012 10:10 am Post subject: |
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Yes, you can ignore pin 1. |
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Dilligaf
Joined: 05 Aug 2003 Posts: 79 Location: Michigan |
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Barf Expert
Joined: 24 Oct 2008 Posts: 1415 Location: Munich, Germany |
Posted: Fri May 18, 2012 3:09 pm Post subject: |
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@Dilligaf:
In all three cases, you need a "serial JP1-interface", not an "adapter". Instructions for this are found in the forum. Note that a "normal serial port" carries +-12 Volts (originally RS232 was invented for something else than modern electronics), and this will fry electronics like a JP1 remote. To the "regular usb to serial" converter: What the "gallon of gasoline"-thread taught us is that experimenting with no-name usb-serial converters is for those with lots of time and very, very little money... (although I personally had success, as I have reported.) |
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Tommy Tyler Expert
Joined: 21 Sep 2003 Posts: 412 Location: Denver mountains |
Posted: Sat May 19, 2012 9:17 am Post subject: |
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Maybe this will help clarify things a bit. There are two basic types of "USB Converters" on the market. The first, and most familiar type, essentially creates a VCP (virtual com port) at a computer that does not have a serial output port, to enable it to communicate with equipment that does. This is the type in the link at the start of this thread. You can identify these easily because they have a DB9 output connector just like the serial connector your computer doesn't have. Its serial data lines exhibit true RS232 voltage levels, often swinging between -12V and +12V, and always resting in the low voltage state when the line is idle.
The second type of converter often goes by a name such as USB-to-RS232 TTL converter, or USB-to-Serial TTL converter, or something similar. Your clues are the designation "TTL" and the absence of a DB9 output connector. TTL refers to the voltage levels of its signals, which are in the 0 to 5V range. This type of converter is also used to create a VCP at a USB port, but the outputs are not intended for transmission to remote equipment. Rather, they are intended to be connected to devices such as microprocessors that accept TTL voltage level signals. Also, the polarity of the data signals is inverted from normal RS232, and the line rests in the higher voltage state when idle.
The second type of converter can sometimes be used as the basis for a flash interface, since the signal levels and polarity are compatible with a remote. But the first type of converter requires a regular serial flash interface be inserted between the converter and the remote to invert the signals and protect from the high voltages. |
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Dilligaf
Joined: 05 Aug 2003 Posts: 79 Location: Michigan |
Posted: Sat May 19, 2012 11:43 am Post subject: |
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Got it. Thanks to both of you.
Mike |
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