Shit, I'm an idiot!
Stevie, you're 100% right I think...Although I'll have to test it out, I'm pretty sure you're right! When looking at the wiring sketch from the AEM forum, that threw me off as the guy was using an external 5V power source to a 2.2k pull up. So I wired it the same way, not realizing that the DTA input is the 5V with it's own 1K pull up...
Let me test it out but for some reason this seems right...
The way I had wired it up the sensor output gave me 4800mv at ambient. This seemed off from Jon's scale. In order for it to be correct, the scale pull up value would have had to be in the 700ohm range.
Now the way I had it wired, both pull ups were in parallel to the signal line. The parallel sum of the DTA's 1K and my external 2.2k is 688ohm. Very close to my estimated 700ohm in the previous paragraph... Which seems to confirm just what you said Stevie; I wired the external 5V and 2.2k pull-up for NOTHING!!!
I'll let you guys know...
Thanks again very much.
AEM temp sensor scaling
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Re: AEM temp sensor scaling
Yeah you only need the external pull-up if wiring to an AV, AT's have it built in as discussed.
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Re: AEM temp sensor scaling
Crap - I didn't realize you were withing the 5v in external. Follow the spreadsheet as the 1K pull up to 5v is internal.Simon P. wrote:Shit, I'm an idiot!
Stevie, you're 100% right I think...Although I'll have to test it out, I'm pretty sure you're right! When looking at the wiring sketch from the AEM forum, that threw me off as the guy was using an external 5V power source to a 2.2k pull up. So I wired it the same way, not realizing that the DTA input is the 5V with it's own 1K pull up...
Let me test it out but for some reason this seems right...
The way I had wired it up the sensor output gave me 4800mv at ambient. This seemed off from Jon's scale. In order for it to be correct, the scale pull up value would have had to be in the 700ohm range.
Now the way I had it wired, both pull ups were in parallel to the signal line. The parallel sum of the DTA's 1K and my external 2.2k is 688ohm. Very close to my estimated 700ohm in the previous paragraph... Which seems to confirm just what you said Stevie; I wired the external 5V and 2.2k pull-up for NOTHING!!!
I'll let you guys know...
Thanks again very much.
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