Map swicher
Map swicher
05-08-2007, 04:23 PM
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Re: Map swicher
It's easy, use a 512k, 1M, or 2M EE/EPROM/Flash chip instead of a 256k. You'll probably want to make a little daughterboard to adapt the different chip to go where the stock location is though.
I've done switching like this before, I don't have any daughterboards left though because I only made a small batch for a special project.
Here's how it works: You'll have additional (higher) address lines for the larger sized memory array, so you can switch those on or off. You're manually toggling an address line(s), and the ECU accesses the other address lines like it normally does. The ECU is now accessing a different area in the chip, but it doesn't know that and doesn't care. You're now accessing the 256k-512k area in the chip instead of the 0-256k area, if that makes sense..
A 512k can now house 2 programs (1 extra address line; 2 combinations), a 1M can house 4 programs (2 extra address lines; 4 combinations), etc.
It's very simple to do if you want to switch while the car/ECU is off; you can just jumper one of the higher address lines to ground and access a new program. You'll need to tie the un-accessed lines to 5V power through a 10k or 15k resistor to keep them from floating. You can use a computer jumper, DIP switch, whatever to switch where it needs to go.
You'll actually be using a different program, not just a different map. To switch maps, you'll use identical programs with modified maps.
If you want to switch maps on the fly, with the ECU on, you'll have to change your game plan. Now you're looking at conditioning/converting (one voltage to another) and debouncing (keeping it from chattering when a switch makes contact) an input, and then switching the address lines with that conditioned input. This is fairly simple also, but quite a bit more involved. I've seen some very simple ways of doing this, but they're pretty ghetto and tend to make the ECU crash sometimes because it gets corrupted data during the time when the programs are switched. This won't damage the ECU, you'll usually just have to cycle power with the key and everything is fine. If you do the on the fly switching a proper way, you won't have to worry about this.
This is all very simple stuff, it's just hard to do without making a little circuit board because you'll need a place to put additional stuff, etc. The board replaces the socket that normally goes in the ECU, and has a socket on it for the bigger chip. I'm sure you can probably find boards to do this floating around on the internet; there is a lot of people doing this stuff now. If you can't find anything I could make a small batch in a few weeks if you're willing to part with some money (and if there are a few other people who would want this local to you).
Note: You don't need any special tuning software or anything like that; you just have to make sure that whatever EE/EPROM/Flash programmer has the capability to program larger chips. This means you can use Hondata, Crome, whatever to do the tuning.
I've done switching like this before, I don't have any daughterboards left though because I only made a small batch for a special project.
Here's how it works: You'll have additional (higher) address lines for the larger sized memory array, so you can switch those on or off. You're manually toggling an address line(s), and the ECU accesses the other address lines like it normally does. The ECU is now accessing a different area in the chip, but it doesn't know that and doesn't care. You're now accessing the 256k-512k area in the chip instead of the 0-256k area, if that makes sense..
A 512k can now house 2 programs (1 extra address line; 2 combinations), a 1M can house 4 programs (2 extra address lines; 4 combinations), etc.
It's very simple to do if you want to switch while the car/ECU is off; you can just jumper one of the higher address lines to ground and access a new program. You'll need to tie the un-accessed lines to 5V power through a 10k or 15k resistor to keep them from floating. You can use a computer jumper, DIP switch, whatever to switch where it needs to go.
You'll actually be using a different program, not just a different map. To switch maps, you'll use identical programs with modified maps.
If you want to switch maps on the fly, with the ECU on, you'll have to change your game plan. Now you're looking at conditioning/converting (one voltage to another) and debouncing (keeping it from chattering when a switch makes contact) an input, and then switching the address lines with that conditioned input. This is fairly simple also, but quite a bit more involved. I've seen some very simple ways of doing this, but they're pretty ghetto and tend to make the ECU crash sometimes because it gets corrupted data during the time when the programs are switched. This won't damage the ECU, you'll usually just have to cycle power with the key and everything is fine. If you do the on the fly switching a proper way, you won't have to worry about this.
This is all very simple stuff, it's just hard to do without making a little circuit board because you'll need a place to put additional stuff, etc. The board replaces the socket that normally goes in the ECU, and has a socket on it for the bigger chip. I'm sure you can probably find boards to do this floating around on the internet; there is a lot of people doing this stuff now. If you can't find anything I could make a small batch in a few weeks if you're willing to part with some money (and if there are a few other people who would want this local to you).
Note: You don't need any special tuning software or anything like that; you just have to make sure that whatever EE/EPROM/Flash programmer has the capability to program larger chips. This means you can use Hondata, Crome, whatever to do the tuning.
Last edited by Fabrik8; 05-08-2007 at 06:00 PM.
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