t vago's MPGuino workspace thread, continued

[alvin_wj]

Hi t vago. Just wanna ask silly question here. I have built the MPGuino based on DCB (metric version, arduino uno) for my car like 5-6 years ago and i have completely lost at the current software development.

Now, i want to build one for my motorcycle (Ninja 250 or Ninja 300 in US).
For this build, i want to use Arduino Nano v3 atmega328p + I2C serial interface for the LCD 16x2 or 20x4. Is it compatible with your version? I'm gonna build it based on schematic found in here:
http://ecomodder.com/wiki/images/7/7..._Schematic.GIF

Thank you in advance. Sorry to ask this silly question, but had read from first to the last page, and still confused

Would be great if you could put your schematic in this thread to help others (like me) who wants to be build new one with the latest software but didn't know if your version is compatible with the schematic above or not

[skybolt]

Now, i want to build one for my motorcycle (Ninja 250 or Ninja 300 in US).
For this build, i want to use Arduino Nano v3 atmega328p + I2C serial interface for the LCD 16x2 or 20x4. Is it compatible with your version? I'm gonna build it based on schematic found in here:
http://ecomodder.com/wiki/images/7/7..._Schematic.GIF

I have Vago's code running on an Arduino Pro Mini 3.3v 8MHz, (Amazon $10 for 3 of them) and it runs well. I also have it running on a TinyDuino, $20 but the size of a quarter. The hard part for anything nonstandard is you may need to make the car-to-arduino interface yourself. It's not hard, just follow the online schematics. You'll need a 7805 12-to-5 volt regulator, two 50k (or 47k or 51k) resistors (or 100k). Also, do NOT power the LCD from the 5V pin on the arduino, you will fry the on-board regulator. For the LCD I recommend the Adafruit button-and-LCD shield, then you only need 2 wires between the arduino and the LCD unit.

You will want to base your design on this schematic instead of the one you're suggesting, since the on-board voltage regulator -- well, I'll just say I've fried many, many arduinos by not using a beefy 7805 regulator. I'm still trying to get around it, and your mileage may vary.


http://ecomodder.com/wiki/images/8/8..._Schematic.GIF

Remember: you can avoid the worst part of the wiring by using an LCD that already has it's own processing, such as the Adafruit one. (Check t-vagos code for all supported LCDs); as managing the wires between a small arduino and 12 pins of an LCD display is nasty. If you do go with the Adafruit LCD be sure to power it from the voltage regulator and not the arduino. Good luck!

The only reason I'm using the 3.3v 8MHz version is so that I can send serial output to a Pi, which will fry if it has 5v inbound on the receive pin, so you can certainly use the 5v arduino nano/pico/mini, etc. I suggest using a breadboard to get your car-to-arduino working before you solder.

Would be great if you could put your schematic in this thread to help others (like me) who wants to be build new one with the latest software but didn't know if your version is compatible with the schematic above or not

As far as I can tell by reverse-engineering t-vago has a series of test mules, but not a particular PCB design. T-vagos stuff works very well on the Meelis hardware if you want a nice, tight package, and I believe it would be trivial to change out the LCD in Meelis' hardware from a 16x2 to a larger display (20x4?); I have given up on LCDs, but IIRC there are many adaptations already using 4-line displays, so I'd assume t's code supports it as well.

[skybolt]

Originally Posted by t vago

Not sure how the Arduino digitalWrite functions will interact with the MPGuino code, but I do not think they'll be a problem.

I seem to have located a problem in the digital read functions. In a nutshell, it won't read from my fuel injector, which is a 13v ground-read. I will walk you through the specifics, but I believe D2 and 3 are soaking up the 5v signal.

Let me start by saying that I first ran into the problem on a hardware test bed, basically a long breadboard with a 7508, one electrolytic cap (330uf) and a ceramic cap (104, so .1uf) on the regulator. I think it should have been .01 but it has not been the source of the problem. (I also have 51k resistors and I can switch back and forth between 5.1 and 3.3v zeners. I like to use 3.3v arduinos and I don't know if 5.1 will fry a D pin).

I used a voltmeter to check the voltage at D2/3 and it was near zero. I unplugged the 4 car wires and check the resistance with a voltmeter, and it changed into capacitive mode and read .01 nf. I unplugged the board, and it read 51k, as it should have from the start.

I then checked the voltage at the D2/3 pins on my Meelis hardware, and it read 5v (it's a 5v board with 5.1v zeners, so that's what I'd expect). Then I bypassed the Meelis resistors and zeners, and used my breadboard to pass input to the Meelis pins. It works as expected, properly reading RPMs and fuel.

I then installed this code (attached) on the Meelis hardware, as configured, and it no longer reads fuel. I can only conclude it's in the code. I can continue to test any number of physical scenarios, but you know know my ISP board is a bit dodgy, so re-flashing the Meelis hardware isn't something I want to do a lot of, but if I hold the ISP shield just right, all the pins make contact and it will compile and load properly.

The code has a few changes, mostly parameters and I changed the string date to 2017-02-10 (it read 08 even though the code title is 10 and I wasn't sure if it was loading on the Meelis until I changed the boot string).

[alvin_wj]

Originally Posted by skybolt

I have Vago's code running on an Arduino Pro Mini 3.3v 8MHz, (Amazon $10 for 3 of them) and it runs well. I also have it running on a TinyDuino, $20 but the size of a quarter. The hard part for anything nonstandard is you may need to make the car-to-arduino interface yourself. It's not hard, just follow the online schematics. You'll need a 7805 12-to-5 volt regulator, two 50k (or 47k or 51k) resistors (or 100k). Also, do NOT power the LCD from the 5V pin on the arduino, you will fry the on-board regulator. For the LCD I recommend the Adafruit button-and-LCD shield, then you only need 2 wires between the arduino and the LCD unit.

You will want to base your design on this schematic instead of the one you're suggesting, since the on-board voltage regulator -- well, I'll just say I've fried many, many arduinos by not using a beefy 7805 regulator. I'm still trying to get around it, and your mileage may vary.


http://ecomodder.com/wiki/images/8/8..._Schematic.GIF

Dear Skybolt, thank you for your reply. I forgot to mention that my MPGuino were using 7805 that you mention. I feel satisfied though when build my first MPGuino but cannot stand to build one more using that method. That's why i bought the Nano as i didn't have to wire all the component (atmega, crystal, caps, resistor, and so on). And you read my mine. I do want to use the 7805 for powering the arduino, and the LCD

Originally Posted by skybolt

Remember: you can avoid the worst part of the wiring by using an LCD that already has it's own processing, such as the Adafruit one. (Check t-vagos code for all supported LCDs); as managing the wires between a small arduino and 12 pins of an LCD display is nasty. If you do go with the Adafruit LCD be sure to power it from the voltage regulator and not the arduino. Good luck!

The only reason I'm using the 3.3v 8MHz version is so that I can send serial output to a Pi, which will fry if it has 5v inbound on the receive pin, so you can certainly use the 5v arduino nano/pico/mini, etc. I suggest using a breadboard to get your car-to-arduino working before you solder.



As far as I can tell by reverse-engineering t-vago has a series of test mules, but not a particular PCB design. T-vagos stuff works very well on the Meelis hardware if you want a nice, tight package, and I believe it would be trivial to change out the LCD in Meelis' hardware from a 16x2 to a larger display (20x4?); I have given up on LCDs, but IIRC there are many adaptations already using 4-line displays, so I'd assume t's code supports it as well.

I do love the idea to bought MPGuino kit to save time, but if you've been to my country, our customs are really pain in the a**. For example, anything that have any price tag >$50 will be charged for an extra tax. And the process itself are wasting more time than to buy the component and assembling it

That's why i want to build MPGuino by myself again

At last, my Nano are arrived and just found out that my zener diode stock is run out. Must have 1-2 days more for the zener to arrive lol.
Many thanks for the reply i hope this build not gonna be as hard as the first one

[skybolt]

Originally Posted by alvin_wj

At last, my Nano are arrived and just found out that my zener diode stock is run out. Must have 1-2 days more for the zener to arrive lol.
Many thanks for the reply i hope this build not gonna be as hard as the first one

Good luck -- it can definitely be a pain. I'd use some type of prototyping board to limit damage to the nano board when perfecting your circuit, something like this:

or

[skybolt]

Originally Posted by t vago

Not sure how the Arduino digitalWrite functions will interact with the MPGuino code, but I do not think they'll be a problem.

I'm re-checking the 0210 code on Meelis' hardware to make sure I went through the built-in resistor/diode array and if so if it works or not. Stand by.

[skybolt]

Originally Posted by skybolt

I'm re-checking the 0210 code on Meelis' hardware to make sure I went through the built-in resistor/diode array and if so if it works or not. Stand by.

Disregard for now -- 2010 code on Meelis hardware with Meelis input functioning correctly.

[skybolt]

Originally Posted by t vago

Not sure how the Arduino digitalWrite functions will interact with the MPGuino code, but I do not think they'll be a problem.

Hold off on code investigations for now. I re-tested the 0210 code with the Meelis hardware and Meelis resistor/diode array. Works as expected. I now have sufficient clip-on wires to make more robust tests. Will advise. Next test is to use the Meelis resistor-diode array to talk to Arduino Pro Mini board. I can't imagine what I could have possibly screwed up; it's just two components and a wire. Maybe something is wrong with the breadboard (melted inside, etc)

[skybolt]

My speed sensor is only putting out 4.2 volts -- none of the arduinos can read it, but inexplicably the speedometer still functions correctly. I will locate/repair the physical damage and resume testing.

**sigh**

[skybolt]

Originally Posted by skybolt

My speed sensor is only putting out 4.2 volts -- none of the arduinos can read it, but inexplicably the speedometer still functions correctly. I will locate/repair the physical damage and resume testing.

**sigh**

Success!! I blew the zener diode for the speedometer input. I have verified good data with version 1.93 (2015-05-20).

Resuming testing on 20170210. Will report.