Arduino go kart EMS

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Fred
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Re: Arduino go kart EMS

Post by Fred »

Weird coils! I'll let you know if I'm in the area for you to do just that. Only time will tell :-)

As for the opto, that sounds accurate.
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Re: Arduino go kart EMS

Post by noisymime »

Just ordered some of these for injector drivers: http://www.st.com/web/en/resource/techn ... 003579.pdf

$1.29 a pop in qtys 10+ from RS including free delivery. Was about the best fully protected driver I could find in that sort of price range. I don't think I missed any glaring weaknesses in the datasheet, so I'll see how I go when they get here. Have to be better than the generic FETs I'm using now anyway :)
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Fred
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Re: Arduino go kart EMS

Post by Fred »

Am I right? 30V clamp? Not obvious in that document. That's a little low for optimum performance but will work OK. If you don't let the coil kick back it closes slower. I scoped an OEM injector yesterday and saw ~55V spikes permitted by the driver in use, for example.
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Re: Arduino go kart EMS

Post by DonTZ125 »

Doing a quick datasheet check, the VND5N07 that Jean uses on his quad driver board has a 70v clamp.
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Re: Arduino go kart EMS

Post by noisymime »

Been a while between updates, so I thought I'd throw something up. Development is continuing nicely, mostly on the software side of late. The first round of testing boards worked OK, but there were definitely some issues with the design that I'll sort out for the next version.

Firmware has been the focus though and it's starting to reach a pretty usable level. All the 3D and 2D map stuff is done which gives me fuel, ignition, TPS based acceleration enrichment, after start enrichment etc. There's basic stuff like a rev limiter (hard and soft spark cut) and flood clear as well. I'm just working on the ability to nicely set sensor calibration data at the moment (For CLT, IAT and O2) and once that's complete things like warm up enrichment, air temp correction and an AFR target table can be added fairly easily.

I don't seem to have hit the arduinos hardware limits yet, though CPU and EEPROM usage need to be watched fairly closely.

There's a few people showing interest in testing and they have boards in their hands now to try out, so hopefully things should keep ticking along. :lol:
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Re: Arduino go kart EMS

Post by noisymime »

Time for another quick update...

Progress has been really good over the last month or so with the firmware coming along nicely. Lots of testing and small improvements and things are now running really reliably with the current set of capabilities.

The next board design has come ahead in leaps and bounds and I'm hoping to get a small batch printed shortly. I've borrowed a lot of the design from DeuceEFIs Jaguar board (and learned quite a bit in the process), so a HUGE thankyou to him for making that available to people like me. :worship:

In case anyone wants to check it out, the summary page for the next board is at: https://github.com/noisymime/speeduino/wiki/V0.2-board
Note that this board isn't yet finished, there are a few circuits still missing, but it's getting there.
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Re: Arduino go kart EMS

Post by noisymime »

Well the next revision of the board is done and a small batch have been produced for testing. Final spec ended up being a little more limited than I had originally hoped, but it was a sacrifice for sticking with THT for all components.

Image

Specs for the board:
* 4 High impedance injector channels (Each with a LED indicator)
* 4 ignition outputs for 'smart' coils or igniters (capable of 3A at 12v or low current logic level)
* Inputs for CLT, IAT, O2 and TPS
* Optional onboard MAP sensor (MPX4250)
* 2 medium current generic PWM output (3A - Eg Idle control)
* 2 low current digital outputs (Max 40mA)
* Battery voltage reference
* 2 speed sensing inputs (RPM and cam) that supports 0-5v pulses by default of 0-12v / VR signal with plug-in conditioner board ( http://jbperf.com/dual_VR/v2_1.html or another one I'm currently finalising)
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russian
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Re: Arduino go kart EMS

Post by russian »

noisymime wrote:a sacrifice for for sticking with THT for all components.
Is THT really worth a sacrifice? 1206 is not much harder then THT.
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Re: Arduino go kart EMS

Post by DonTZ125 »

Hand soldering an SMT component that you can pick up isn't actually that hard. Hand soldering a SOD323 diode that you ordered by accident when it should have been a SOD123 part - THAT took patience ... :oops:
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Re: Arduino go kart EMS

Post by noisymime »

russian wrote:
noisymime wrote:a sacrifice for for sticking with THT for all components.
Is THT really worth a sacrifice? 1206 is not much harder then THT.
You're right that 1206 isn't too bad at all, the concern is that given this is meant to be a DIY type kit item, whether it would scare people off.

I've (mostly) redone that board with larger SMD parts and it's allowed me to squeeze another 2 channel FET in, which I was really lacking in the original version, but I haven't sent it off to get made yet. I'll see how the THT version works out in testing and then maybe make a decision about what to do for the larger batch.
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