Search found 21 matches
- Fri Dec 27, 2013 8:01 am
- Forum: Dev: Hardware
- Topic: Interfacing with a LCD/tablet dash
- Replies: 14
- Views: 12812
Re: Interfacing with a LCD/tablet dash
The Discovery board it totally is fast enough to run an LCD display. I run one of these in my car: http://www.ebay.com/itm/new-7inch-7-0-800-480-TFT-LCD-Module-Display-Touch-Panel-SSD1963-For-51-AVR-/111140237971?pt=LH_DefaultDomain_0&hash=item19e0797293 The discovery board runs datalogging for ...
- Fri Nov 15, 2013 7:55 pm
- Forum: Dev: Hardware
- Topic: VR + knock module
- Replies: 69
- Views: 162927
Re: [help needed] VR + knock module
It's all greek to me.russian wrote: You are not alone, I've got six Russians fighting about it at http://rusefi.com/forum/viewtopic.php?f=8&t=251
- Thu Nov 14, 2013 8:11 pm
- Forum: Dev: Hardware
- Topic: VR + knock module
- Replies: 69
- Views: 162927
Re: [help needed] VR + knock module
It's easy enough to bodge together a fixed function bandpass filter in code. Here is a good source: http://www-users.cs.york.ac.uk/~fisher/mkfilter/
Acoustic knock detection is still a weak way to go. Ion sensing is much better.
http://vvnet.fi/ville/ion/DIY-Ion-Sensing-2.pdf
Acoustic knock detection is still a weak way to go. Ion sensing is much better.
http://vvnet.fi/ville/ion/DIY-Ion-Sensing-2.pdf
- Thu Nov 14, 2013 8:01 pm
- Forum: Dev: Hardware
- Topic: 6 channel injector module - VNS14NV04
- Replies: 22
- Views: 34506
Re: 6 channel injector module
I like those switches, but man are they slow.
The speed isn't an issue for injectors but with a switching time that long they're going to dissipate quite a bit more heat.
I probably would have gone with the DPAK for better dissipation.
The speed isn't an issue for injectors but with a switching time that long they're going to dissipate quite a bit more heat.
I probably would have gone with the DPAK for better dissipation.
- Fri Nov 08, 2013 6:20 pm
- Forum: Dev: Hardware
- Topic: Thermocouple input?
- Replies: 54
- Views: 42499
Re: Thermocouple input?
The MAX31855 is about the simplest way to do a thermocouple input. It handles the cold junction compensation, linearization and A/D conversion. A simple bit banged interface and you're all set. It's even cheap. If I had known it existed befoe today I probably would have put one on my digital dashboa...
- Sun Nov 03, 2013 8:31 pm
- Forum: Dev: Software
- Topic: A different approach.
- Replies: 46
- Views: 40643
Re: A different approach.
Cars used to run open loop at WOT but they don't any more. Most modern ECUs use a WBO2 because WOT is a tested parameter for the EPA and they can't get away without it. That's why you can get a Bosch WBO2 sensor for cheap now. I'd use a separate table for the correction so you can wipe it without wo...
- Fri Nov 01, 2013 3:16 am
- Forum: Dev: Hardware
- Topic: What about fancy output drivers?
- Replies: 12
- Views: 11546
Re: What about fancy output drivers?
Not enough drive current.
A saturated injector takes about an amp to drive. I peak/hold injector uses about 4A for a milisecond or so then 1A hold.
That driver can only do 625ma per driver.
A saturated injector takes about an amp to drive. I peak/hold injector uses about 4A for a milisecond or so then 1A hold.
That driver can only do 625ma per driver.
- Thu Oct 31, 2013 7:46 pm
- Forum: Dev: Hardware
- Topic: Variable Reluctance input
- Replies: 15
- Views: 15135
Re: Variable Reluctance input
The Maxim IC is fancy, and only available in fine pitch surface mount. It'll be a total bear to solder by hand. The ON chip is simpler and a dual VR amp, with .050 lead spacing which is easily doable by hand. The big difference between the TI chap and the ON chip are the outputs. The TI chip outputs...
- Thu Oct 31, 2013 7:26 pm
- Forum: Dev: Software
- Topic: A different approach.
- Replies: 46
- Views: 40643
Re: A different approach.
If you want to keep it as simple as possible how about this: A simple alpha N table to get it close (+-5% or so) A WB O2 sensor. A second table with a multiplier based on a single target AFR from the WB O2 that's the same size as the main alpha N table. A clamped feedback loop that ticks fuel correc...
- Fri Oct 25, 2013 6:00 pm
- Forum: Dev: Software
- Topic: Fuel Pump control.
- Replies: 10
- Views: 11034
Re: Fuel Pump control.
I'd do it with more of a watchdog approach.
Turning on the ECU and getting crank signals reset the watchdog. If the watchdog expires, turn off the fuel pump.
Turning on the ECU and getting crank signals reset the watchdog. If the watchdog expires, turn off the fuel pump.
- Thu Oct 24, 2013 8:38 pm
- Forum: Dev: Software
- Topic: Fuel Pump control.
- Replies: 10
- Views: 11034
Re: Fuel Pump control.
It's important to turn off the fuel pump ater a couple of seconds of no crank angle changes.
You do not want the fuel pump running for more than a few seconds if the engine stalls for safety.
Think fuel line ruptures.
You do not want the fuel pump running for more than a few seconds if the engine stalls for safety.
Think fuel line ruptures.
- Sat Oct 19, 2013 7:15 pm
- Forum: Dev: Hardware
- Topic: Power supply - Sergey89
- Replies: 20
- Views: 22299
Re: Power supply - Sergey89
That's why I used a 3.3v rated voltage transorb http://www.semtech.com/apps/product.php?pn=SRDA3.3-4 I'm not worried at all about ripple. There's alread a LDO on the discovery board that the analog stuff references. I also added 470uf caps on the 12v, 5v, and my own 3.3v LDO that I use for pull-ups.
- Fri Oct 18, 2013 8:42 pm
- Forum: Dev: Hardware
- Topic: Injectors driver - Sergey89
- Replies: 4
- Views: 7914
Re: Injectors driver - Sergey89
National used to have 4 channel peak/hold injector drivers but I don't see them on the TI website.
They still have the LM1949 but it's kind of bulky. They have lots of high current automotive drivers as well.
They still have the LM1949 but it's kind of bulky. They have lots of high current automotive drivers as well.
- Fri Oct 18, 2013 8:34 pm
- Forum: Dev: Hardware
- Topic: analog inputs: op-amp + divider - Russian - now MCP6004
- Replies: 124
- Views: 137745
Re: analog inputs: op-amp + divider
if 15pf and <1ua leakage is too much input loading, you're not reading automotive sensors.Sergey89 wrote:TVS and Zener diodes has a large leakage current. Low leakage diode is more preferred device (BAV199 for example).
- Fri Oct 18, 2013 8:28 pm
- Forum: Dev: Hardware
- Topic: Analog inputs - Sergey89
- Replies: 6
- Views: 8188
Re: Analog inputs - Sergey89
R5 - C5 are a nice RC input filter, takes out a lot of hash.
Ditch the opamp and clamp diodes, use a resistor divider and a transorb. I used these http://www.semtech.com/images/datasheet/srda3.3-4.pdf for my i/o protection.
Ditch the opamp and clamp diodes, use a resistor divider and a transorb. I used these http://www.semtech.com/images/datasheet/srda3.3-4.pdf for my i/o protection.
- Fri Oct 18, 2013 8:26 pm
- Forum: Dev: Hardware
- Topic: Triggers - Sergey89
- Replies: 2
- Views: 5038
Re: Triggers - Sergey89
That's a lot of circuitry to replace one of these: http://www.semtech.com/images/datasheet/srda3.3-4.pdf
- Fri Oct 18, 2013 8:23 pm
- Forum: Dev: Hardware
- Topic: Actuators driver - Sergey89
- Replies: 3
- Views: 5223
Re: Actuators driver - Sergey89
How much current do you need to sink?
I used TLE6225G low side drivers with fault protection. Why re-invent the wheel on something this boring?
I used TLE6225G low side drivers with fault protection. Why re-invent the wheel on something this boring?
- Fri Oct 18, 2013 8:21 pm
- Forum: Dev: Hardware
- Topic: Power supply - Sergey89
- Replies: 20
- Views: 22299
Re: Power supply - Sergey89
I used these:
http://www.ebay.com/itm/10PCS-DC-DC-LM2596-Step-Down-Module-Adjustable-Power-Supply-CC-CV-Output-1-3-35V-/380663903236?pt=LH_DefaultDomain_0&hash=item58a1563404
All of my I/O are clamped with transorbs, no worry about dumping into the power supply.
http://www.ebay.com/itm/10PCS-DC-DC-LM2596-Step-Down-Module-Adjustable-Power-Supply-CC-CV-Output-1-3-35V-/380663903236?pt=LH_DefaultDomain_0&hash=item58a1563404
All of my I/O are clamped with transorbs, no worry about dumping into the power supply.
- Mon Oct 14, 2013 7:33 am
- Forum: Dev: Hardware
- Topic: analog inputs: op-amp + divider - Russian - now MCP6004
- Replies: 124
- Views: 137745
Re: analog inputs: op-amp + divider
Keep the input protection. It's much better to blow out an external diode then the a/d inputs. I use a TVS diodes, in a quad unipolar 3.3v package for protection. I also don't bother with the buffer opamp. I have a 'universal' input with an input resistor, a pull up and down and a cap to ground, fol...
- Wed Sep 04, 2013 5:55 pm
- Forum: Dev: Software
- Topic: output scheduling resolution
- Replies: 20
- Views: 37295
Re: output scheduling resolution
If you can keep jitter under 2us when doing the processing you need to do then you're golden.
- Tue Sep 03, 2013 5:11 am
- Forum: Dev: Software
- Topic: output scheduling resolution
- Replies: 20
- Views: 37295
Re: output scheduling resolution
The real test will be to make about a dozen timers all running with slightly different periods at the same time and check the jitter then. Also make each handler burn a hundered clock cycles or so to get a more realistic load. Assuming you want to be able to control an eight cylinder engine you need...